From 17d9ddc72fb8bba0d4f67868c9c612e472a594a9 Mon Sep 17 00:00:00 2001 From: "Pallipadi, Venkatesh" Date: Wed, 10 Feb 2010 15:23:44 -0800 Subject: rbtree: Add support for augmented rbtrees Add support for augmented rbtrees in core rbtree code. This will be used in subsequent patches, in x86 PAT code, which needs interval trees to efficiently keep track of PAT ranges. Signed-off-by: Venkatesh Pallipadi LKML-Reference: <20100210232343.GA11465@linux-os.sc.intel.com> Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- include/linux/rbtree.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h index 9c295411d01..8e33a256ea0 100644 --- a/include/linux/rbtree.h +++ b/include/linux/rbtree.h @@ -110,6 +110,7 @@ struct rb_node struct rb_root { struct rb_node *rb_node; + void (*augment_cb)(struct rb_node *node); }; @@ -129,7 +130,9 @@ static inline void rb_set_color(struct rb_node *rb, int color) rb->rb_parent_color = (rb->rb_parent_color & ~1) | color; } -#define RB_ROOT (struct rb_root) { NULL, } +#define RB_ROOT (struct rb_root) { NULL, NULL, } +#define RB_AUGMENT_ROOT(x) (struct rb_root) { NULL, x} + #define rb_entry(ptr, type, member) container_of(ptr, type, member) #define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL) -- cgit v1.2.3-70-g09d2 From 4abc14a733f9002c05623db755aaafdd27fa7a91 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Wed, 20 Jan 2010 14:52:23 +0100 Subject: iommu-api: Rename ->{un}map function pointers to ->{un}map_range The new function pointer names match better with the top-level functions of the iommu-api which are using them. Main intention of this change is to make the ->{un}map pointer names free for two new mapping functions. Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 4 ++-- drivers/base/iommu.c | 4 ++-- drivers/pci/intel-iommu.c | 4 ++-- include/linux/iommu.h | 8 ++++---- 4 files changed, 10 insertions(+), 10 deletions(-) (limited to 'include') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index adb0ba02570..59cae7c4df5 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -2515,8 +2515,8 @@ static struct iommu_ops amd_iommu_ops = { .domain_destroy = amd_iommu_domain_destroy, .attach_dev = amd_iommu_attach_device, .detach_dev = amd_iommu_detach_device, - .map = amd_iommu_map_range, - .unmap = amd_iommu_unmap_range, + .map_range = amd_iommu_map_range, + .unmap_range = amd_iommu_unmap_range, .iova_to_phys = amd_iommu_iova_to_phys, .domain_has_cap = amd_iommu_domain_has_cap, }; diff --git a/drivers/base/iommu.c b/drivers/base/iommu.c index 8ad4ffea692..f4c86c42929 100644 --- a/drivers/base/iommu.c +++ b/drivers/base/iommu.c @@ -83,14 +83,14 @@ EXPORT_SYMBOL_GPL(iommu_detach_device); int iommu_map_range(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot) { - return iommu_ops->map(domain, iova, paddr, size, prot); + return iommu_ops->map_range(domain, iova, paddr, size, prot); } EXPORT_SYMBOL_GPL(iommu_map_range); void iommu_unmap_range(struct iommu_domain *domain, unsigned long iova, size_t size) { - iommu_ops->unmap(domain, iova, size); + iommu_ops->unmap_range(domain, iova, size); } EXPORT_SYMBOL_GPL(iommu_unmap_range); diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 417312528dd..a714e3db13c 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -3714,8 +3714,8 @@ static struct iommu_ops intel_iommu_ops = { .domain_destroy = intel_iommu_domain_destroy, .attach_dev = intel_iommu_attach_device, .detach_dev = intel_iommu_detach_device, - .map = intel_iommu_map_range, - .unmap = intel_iommu_unmap_range, + .map_range = intel_iommu_map_range, + .unmap_range = intel_iommu_unmap_range, .iova_to_phys = intel_iommu_iova_to_phys, .domain_has_cap = intel_iommu_domain_has_cap, }; diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 3af4ffd591b..0f18f37a650 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -36,10 +36,10 @@ struct iommu_ops { void (*domain_destroy)(struct iommu_domain *domain); int (*attach_dev)(struct iommu_domain *domain, struct device *dev); void (*detach_dev)(struct iommu_domain *domain, struct device *dev); - int (*map)(struct iommu_domain *domain, unsigned long iova, - phys_addr_t paddr, size_t size, int prot); - void (*unmap)(struct iommu_domain *domain, unsigned long iova, - size_t size); + int (*map_range)(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot); + void (*unmap_range)(struct iommu_domain *domain, unsigned long iova, + size_t size); phys_addr_t (*iova_to_phys)(struct iommu_domain *domain, unsigned long iova); int (*domain_has_cap)(struct iommu_domain *domain, -- cgit v1.2.3-70-g09d2 From cefc53c7f494240d4813c80154c7617452d1904d Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 8 Jan 2010 13:35:09 +0100 Subject: iommu-api: Add iommu_map and iommu_unmap functions These two functions provide support for mapping and unmapping physical addresses to io virtual addresses. The difference to the iommu_(un)map_range() is that the new functions take a gfp_order parameter instead of a size. This allows the IOMMU backend implementations to detect easier if a given range can be mapped by larger page sizes. These new functions should replace the old ones in the long term. Signed-off-by: Joerg Roedel --- drivers/base/iommu.c | 31 +++++++++++++++++++++++++++++++ include/linux/iommu.h | 16 ++++++++++++++++ 2 files changed, 47 insertions(+) (limited to 'include') diff --git a/drivers/base/iommu.c b/drivers/base/iommu.c index f4c86c42929..cf7cbec116e 100644 --- a/drivers/base/iommu.c +++ b/drivers/base/iommu.c @@ -107,3 +107,34 @@ int iommu_domain_has_cap(struct iommu_domain *domain, return iommu_ops->domain_has_cap(domain, cap); } EXPORT_SYMBOL_GPL(iommu_domain_has_cap); + +int iommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, int gfp_order, int prot) +{ + unsigned long invalid_mask; + size_t size; + + size = 0x1000UL << gfp_order; + invalid_mask = size - 1; + + BUG_ON((iova | paddr) & invalid_mask); + + return iommu_ops->map_range(domain, iova, paddr, size, prot); +} +EXPORT_SYMBOL_GPL(iommu_map); + +int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order) +{ + unsigned long invalid_mask; + size_t size; + + size = 0x1000UL << gfp_order; + invalid_mask = size - 1; + + BUG_ON(iova & invalid_mask); + + iommu_ops->unmap_range(domain, iova, size); + + return gfp_order; +} +EXPORT_SYMBOL_GPL(iommu_unmap); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 0f18f37a650..6d0035bb1a0 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -60,6 +60,10 @@ extern int iommu_map_range(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot); extern void iommu_unmap_range(struct iommu_domain *domain, unsigned long iova, size_t size); +extern int iommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, int gfp_order, int prot); +extern int iommu_unmap(struct iommu_domain *domain, unsigned long iova, + int gfp_order); extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, unsigned long iova); extern int iommu_domain_has_cap(struct iommu_domain *domain, @@ -108,6 +112,18 @@ static inline void iommu_unmap_range(struct iommu_domain *domain, { } +static inline int iommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, int gfp_order, int prot) +{ + return -ENODEV; +} + +static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova, + int gfp_order) +{ + return -ENODEV; +} + static inline phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, unsigned long iova) { -- cgit v1.2.3-70-g09d2 From 67651786948c360c3122b8a17cb1e59209d50880 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 21 Jan 2010 16:32:27 +0100 Subject: iommu-api: Add ->{un}map callbacks to iommu_ops This patch adds new callbacks for mapping and unmapping pages to the iommu_ops structure. These callbacks are aware of page sizes which makes them different to the ->{un}map_range callbacks. Signed-off-by: Joerg Roedel --- drivers/base/iommu.c | 6 ++++++ include/linux/iommu.h | 4 ++++ 2 files changed, 10 insertions(+) (limited to 'include') diff --git a/drivers/base/iommu.c b/drivers/base/iommu.c index cf7cbec116e..55d37e4609e 100644 --- a/drivers/base/iommu.c +++ b/drivers/base/iommu.c @@ -119,6 +119,9 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova, BUG_ON((iova | paddr) & invalid_mask); + if (iommu_ops->map) + return iommu_ops->map(domain, iova, paddr, gfp_order, prot); + return iommu_ops->map_range(domain, iova, paddr, size, prot); } EXPORT_SYMBOL_GPL(iommu_map); @@ -133,6 +136,9 @@ int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order) BUG_ON(iova & invalid_mask); + if (iommu_ops->unmap) + return iommu_ops->unmap(domain, iova, gfp_order); + iommu_ops->unmap_range(domain, iova, size); return gfp_order; diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 6d0035bb1a0..5a7a3d888da 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -36,6 +36,10 @@ struct iommu_ops { void (*domain_destroy)(struct iommu_domain *domain); int (*attach_dev)(struct iommu_domain *domain, struct device *dev); void (*detach_dev)(struct iommu_domain *domain, struct device *dev); + int (*map)(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, int gfp_order, int prot); + int (*unmap)(struct iommu_domain *domain, unsigned long iova, + int gfp_order); int (*map_range)(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot); void (*unmap_range)(struct iommu_domain *domain, unsigned long iova, -- cgit v1.2.3-70-g09d2 From 12c7389abe5786349d3ea6da1961cf78d0c1c7cd Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 21 Jan 2010 11:50:28 +0100 Subject: iommu-api: Remove iommu_{un}map_range functions These functions are not longer used and can be removed savely. There functionality is now provided by the iommu_{un}map functions which are also capable of multiple page sizes. Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 48 --------------------------------------------- drivers/base/iommu.c | 26 ++---------------------- include/linux/iommu.h | 20 ------------------- 3 files changed, 2 insertions(+), 92 deletions(-) (limited to 'include') diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 0e068c9ca5f..d8da9988edd 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -2506,52 +2506,6 @@ static int amd_iommu_attach_device(struct iommu_domain *dom, return ret; } -static int amd_iommu_map_range(struct iommu_domain *dom, - unsigned long iova, phys_addr_t paddr, - size_t size, int iommu_prot) -{ - struct protection_domain *domain = dom->priv; - unsigned long i, npages = iommu_num_pages(paddr, size, PAGE_SIZE); - int prot = 0; - int ret; - - if (iommu_prot & IOMMU_READ) - prot |= IOMMU_PROT_IR; - if (iommu_prot & IOMMU_WRITE) - prot |= IOMMU_PROT_IW; - - iova &= PAGE_MASK; - paddr &= PAGE_MASK; - - for (i = 0; i < npages; ++i) { - ret = iommu_map_page(domain, iova, paddr, prot, PAGE_SIZE); - if (ret) - return ret; - - iova += PAGE_SIZE; - paddr += PAGE_SIZE; - } - - return 0; -} - -static void amd_iommu_unmap_range(struct iommu_domain *dom, - unsigned long iova, size_t size) -{ - - struct protection_domain *domain = dom->priv; - unsigned long i, npages = iommu_num_pages(iova, size, PAGE_SIZE); - - iova &= PAGE_MASK; - - for (i = 0; i < npages; ++i) { - iommu_unmap_page(domain, iova, PAGE_SIZE); - iova += PAGE_SIZE; - } - - iommu_flush_tlb_pde(domain); -} - static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova, phys_addr_t paddr, int gfp_order, int iommu_prot) { @@ -2616,8 +2570,6 @@ static struct iommu_ops amd_iommu_ops = { .detach_dev = amd_iommu_detach_device, .map = amd_iommu_map, .unmap = amd_iommu_unmap, - .map_range = amd_iommu_map_range, - .unmap_range = amd_iommu_unmap_range, .iova_to_phys = amd_iommu_iova_to_phys, .domain_has_cap = amd_iommu_domain_has_cap, }; diff --git a/drivers/base/iommu.c b/drivers/base/iommu.c index 55d37e4609e..6e6b6a11b3c 100644 --- a/drivers/base/iommu.c +++ b/drivers/base/iommu.c @@ -80,20 +80,6 @@ void iommu_detach_device(struct iommu_domain *domain, struct device *dev) } EXPORT_SYMBOL_GPL(iommu_detach_device); -int iommu_map_range(struct iommu_domain *domain, unsigned long iova, - phys_addr_t paddr, size_t size, int prot) -{ - return iommu_ops->map_range(domain, iova, paddr, size, prot); -} -EXPORT_SYMBOL_GPL(iommu_map_range); - -void iommu_unmap_range(struct iommu_domain *domain, unsigned long iova, - size_t size) -{ - iommu_ops->unmap_range(domain, iova, size); -} -EXPORT_SYMBOL_GPL(iommu_unmap_range); - phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, unsigned long iova) { @@ -119,10 +105,7 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova, BUG_ON((iova | paddr) & invalid_mask); - if (iommu_ops->map) - return iommu_ops->map(domain, iova, paddr, gfp_order, prot); - - return iommu_ops->map_range(domain, iova, paddr, size, prot); + return iommu_ops->map(domain, iova, paddr, gfp_order, prot); } EXPORT_SYMBOL_GPL(iommu_map); @@ -136,11 +119,6 @@ int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order) BUG_ON(iova & invalid_mask); - if (iommu_ops->unmap) - return iommu_ops->unmap(domain, iova, gfp_order); - - iommu_ops->unmap_range(domain, iova, size); - - return gfp_order; + return iommu_ops->unmap(domain, iova, gfp_order); } EXPORT_SYMBOL_GPL(iommu_unmap); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 5a7a3d888da..be22ad83689 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -40,10 +40,6 @@ struct iommu_ops { phys_addr_t paddr, int gfp_order, int prot); int (*unmap)(struct iommu_domain *domain, unsigned long iova, int gfp_order); - int (*map_range)(struct iommu_domain *domain, unsigned long iova, - phys_addr_t paddr, size_t size, int prot); - void (*unmap_range)(struct iommu_domain *domain, unsigned long iova, - size_t size); phys_addr_t (*iova_to_phys)(struct iommu_domain *domain, unsigned long iova); int (*domain_has_cap)(struct iommu_domain *domain, @@ -60,10 +56,6 @@ extern int iommu_attach_device(struct iommu_domain *domain, struct device *dev); extern void iommu_detach_device(struct iommu_domain *domain, struct device *dev); -extern int iommu_map_range(struct iommu_domain *domain, unsigned long iova, - phys_addr_t paddr, size_t size, int prot); -extern void iommu_unmap_range(struct iommu_domain *domain, unsigned long iova, - size_t size); extern int iommu_map(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, int gfp_order, int prot); extern int iommu_unmap(struct iommu_domain *domain, unsigned long iova, @@ -104,18 +96,6 @@ static inline void iommu_detach_device(struct iommu_domain *domain, { } -static inline int iommu_map_range(struct iommu_domain *domain, - unsigned long iova, phys_addr_t paddr, - size_t size, int prot) -{ - return -ENODEV; -} - -static inline void iommu_unmap_range(struct iommu_domain *domain, - unsigned long iova, size_t size) -{ -} - static inline int iommu_map(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, int gfp_order, int prot) { -- cgit v1.2.3-70-g09d2 From ca037701a025334e724e5c61b3b1082940c8b981 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 2 Mar 2010 19:52:12 +0100 Subject: perf, x86: Add PEBS infrastructure This patch implements support for Intel Precise Event Based Sampling, which is an alternative counter mode in which the counter triggers a hardware assist to collect information on events. The hardware assist takes a trap like snapshot of a subset of the machine registers. This data is written to the Intel Debug-Store, which can be programmed with a data threshold at which to raise a PMI. With the PEBS hardware assist being trap like, the reported IP is always one instruction after the actual instruction that triggered the event. This implements a simple PEBS model that always takes a single PEBS event at a time. This is done so that the interaction with the rest of the system is as expected (freq adjust, period randomization, lbr, callchains, etc.). It adds an ABI element: perf_event_attr::precise, which indicates that we wish to use this (constrained, but precise) mode. Signed-off-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: paulus@samba.org Cc: eranian@google.com Cc: robert.richter@amd.com Cc: fweisbec@gmail.com LKML-Reference: <20100304140100.392111285@chello.nl> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.c | 223 +++++------- arch/x86/kernel/cpu/perf_event_intel.c | 150 ++------ arch/x86/kernel/cpu/perf_event_intel_ds.c | 557 ++++++++++++++++++++++++++++++ include/linux/perf_event.h | 3 +- 4 files changed, 671 insertions(+), 262 deletions(-) create mode 100644 arch/x86/kernel/cpu/perf_event_intel_ds.c (limited to 'include') diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 1d665a0b202..0c03d5c1671 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -31,45 +31,6 @@ static u64 perf_event_mask __read_mostly; -/* The maximal number of PEBS events: */ -#define MAX_PEBS_EVENTS 4 - -/* The size of a BTS record in bytes: */ -#define BTS_RECORD_SIZE 24 - -/* The size of a per-cpu BTS buffer in bytes: */ -#define BTS_BUFFER_SIZE (BTS_RECORD_SIZE * 2048) - -/* The BTS overflow threshold in bytes from the end of the buffer: */ -#define BTS_OVFL_TH (BTS_RECORD_SIZE * 128) - - -/* - * Bits in the debugctlmsr controlling branch tracing. - */ -#define X86_DEBUGCTL_TR (1 << 6) -#define X86_DEBUGCTL_BTS (1 << 7) -#define X86_DEBUGCTL_BTINT (1 << 8) -#define X86_DEBUGCTL_BTS_OFF_OS (1 << 9) -#define X86_DEBUGCTL_BTS_OFF_USR (1 << 10) - -/* - * A debug store configuration. - * - * We only support architectures that use 64bit fields. - */ -struct debug_store { - u64 bts_buffer_base; - u64 bts_index; - u64 bts_absolute_maximum; - u64 bts_interrupt_threshold; - u64 pebs_buffer_base; - u64 pebs_index; - u64 pebs_absolute_maximum; - u64 pebs_interrupt_threshold; - u64 pebs_event_reset[MAX_PEBS_EVENTS]; -}; - struct event_constraint { union { unsigned long idxmsk[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; @@ -88,17 +49,29 @@ struct amd_nb { }; struct cpu_hw_events { + /* + * Generic x86 PMC bits + */ struct perf_event *events[X86_PMC_IDX_MAX]; /* in counter order */ unsigned long active_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; unsigned long interrupts; int enabled; - struct debug_store *ds; int n_events; int n_added; int assign[X86_PMC_IDX_MAX]; /* event to counter assignment */ u64 tags[X86_PMC_IDX_MAX]; struct perf_event *event_list[X86_PMC_IDX_MAX]; /* in enabled order */ + + /* + * Intel DebugStore bits + */ + struct debug_store *ds; + u64 pebs_enabled; + + /* + * AMD specific bits + */ struct amd_nb *amd_nb; }; @@ -112,12 +85,24 @@ struct cpu_hw_events { #define EVENT_CONSTRAINT(c, n, m) \ __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n)) +/* + * Constraint on the Event code. + */ #define INTEL_EVENT_CONSTRAINT(c, n) \ EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVTSEL_MASK) +/* + * Constraint on the Event code + UMask + fixed-mask + */ #define FIXED_EVENT_CONSTRAINT(c, n) \ EVENT_CONSTRAINT(c, (1ULL << (32+n)), INTEL_ARCH_FIXED_MASK) +/* + * Constraint on the Event code + UMask + */ +#define PEBS_EVENT_CONSTRAINT(c, n) \ + EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVENT_MASK) + #define EVENT_CONSTRAINT_END \ EVENT_CONSTRAINT(0, 0, 0) @@ -128,6 +113,9 @@ struct cpu_hw_events { * struct x86_pmu - generic x86 pmu */ struct x86_pmu { + /* + * Generic x86 PMC bits + */ const char *name; int version; int (*handle_irq)(struct pt_regs *); @@ -146,10 +134,6 @@ struct x86_pmu { u64 event_mask; int apic; u64 max_period; - u64 intel_ctrl; - void (*enable_bts)(u64 config); - void (*disable_bts)(void); - struct event_constraint * (*get_event_constraints)(struct cpu_hw_events *cpuc, struct perf_event *event); @@ -162,6 +146,19 @@ struct x86_pmu { void (*cpu_starting)(int cpu); void (*cpu_dying)(int cpu); void (*cpu_dead)(int cpu); + + /* + * Intel Arch Perfmon v2+ + */ + u64 intel_ctrl; + + /* + * Intel DebugStore bits + */ + int bts, pebs; + int pebs_record_size; + void (*drain_pebs)(struct pt_regs *regs); + struct event_constraint *pebs_constraints; }; static struct x86_pmu x86_pmu __read_mostly; @@ -293,110 +290,14 @@ static void release_pmc_hardware(void) #endif } -static inline bool bts_available(void) -{ - return x86_pmu.enable_bts != NULL; -} - -static void init_debug_store_on_cpu(int cpu) -{ - struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; - - if (!ds) - return; - - wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, - (u32)((u64)(unsigned long)ds), - (u32)((u64)(unsigned long)ds >> 32)); -} - -static void fini_debug_store_on_cpu(int cpu) -{ - if (!per_cpu(cpu_hw_events, cpu).ds) - return; - - wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0); -} - -static void release_bts_hardware(void) -{ - int cpu; - - if (!bts_available()) - return; - - get_online_cpus(); - - for_each_online_cpu(cpu) - fini_debug_store_on_cpu(cpu); - - for_each_possible_cpu(cpu) { - struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; - - if (!ds) - continue; - - per_cpu(cpu_hw_events, cpu).ds = NULL; - - kfree((void *)(unsigned long)ds->bts_buffer_base); - kfree(ds); - } - - put_online_cpus(); -} - -static int reserve_bts_hardware(void) -{ - int cpu, err = 0; - - if (!bts_available()) - return 0; - - get_online_cpus(); - - for_each_possible_cpu(cpu) { - struct debug_store *ds; - void *buffer; - - err = -ENOMEM; - buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL); - if (unlikely(!buffer)) - break; - - ds = kzalloc(sizeof(*ds), GFP_KERNEL); - if (unlikely(!ds)) { - kfree(buffer); - break; - } - - ds->bts_buffer_base = (u64)(unsigned long)buffer; - ds->bts_index = ds->bts_buffer_base; - ds->bts_absolute_maximum = - ds->bts_buffer_base + BTS_BUFFER_SIZE; - ds->bts_interrupt_threshold = - ds->bts_absolute_maximum - BTS_OVFL_TH; - - per_cpu(cpu_hw_events, cpu).ds = ds; - err = 0; - } - - if (err) - release_bts_hardware(); - else { - for_each_online_cpu(cpu) - init_debug_store_on_cpu(cpu); - } - - put_online_cpus(); - - return err; -} +static int reserve_ds_buffers(void); +static void release_ds_buffers(void); static void hw_perf_event_destroy(struct perf_event *event) { if (atomic_dec_and_mutex_lock(&active_events, &pmc_reserve_mutex)) { release_pmc_hardware(); - release_bts_hardware(); + release_ds_buffers(); mutex_unlock(&pmc_reserve_mutex); } } @@ -459,7 +360,7 @@ static int __hw_perf_event_init(struct perf_event *event) if (!reserve_pmc_hardware()) err = -EBUSY; else - err = reserve_bts_hardware(); + err = reserve_ds_buffers(); } if (!err) atomic_inc(&active_events); @@ -537,7 +438,7 @@ static int __hw_perf_event_init(struct perf_event *event) if ((attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) && (hwc->sample_period == 1)) { /* BTS is not supported by this architecture. */ - if (!bts_available()) + if (!x86_pmu.bts) return -EOPNOTSUPP; /* BTS is currently only allowed for user-mode. */ @@ -995,6 +896,7 @@ static void x86_pmu_unthrottle(struct perf_event *event) void perf_event_print_debug(void) { u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed; + u64 pebs; struct cpu_hw_events *cpuc; unsigned long flags; int cpu, idx; @@ -1012,12 +914,14 @@ void perf_event_print_debug(void) rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status); rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow); rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed); + rdmsrl(MSR_IA32_PEBS_ENABLE, pebs); pr_info("\n"); pr_info("CPU#%d: ctrl: %016llx\n", cpu, ctrl); pr_info("CPU#%d: status: %016llx\n", cpu, status); pr_info("CPU#%d: overflow: %016llx\n", cpu, overflow); pr_info("CPU#%d: fixed: %016llx\n", cpu, fixed); + pr_info("CPU#%d: pebs: %016llx\n", cpu, pebs); } pr_info("CPU#%d: active: %016llx\n", cpu, *(u64 *)cpuc->active_mask); @@ -1333,6 +1237,7 @@ undo: #include "perf_event_amd.c" #include "perf_event_p6.c" +#include "perf_event_intel_ds.c" #include "perf_event_intel.c" static int __cpuinit @@ -1464,6 +1369,32 @@ static const struct pmu pmu = { .unthrottle = x86_pmu_unthrottle, }; +/* + * validate that we can schedule this event + */ +static int validate_event(struct perf_event *event) +{ + struct cpu_hw_events *fake_cpuc; + struct event_constraint *c; + int ret = 0; + + fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO); + if (!fake_cpuc) + return -ENOMEM; + + c = x86_pmu.get_event_constraints(fake_cpuc, event); + + if (!c || !c->weight) + ret = -ENOSPC; + + if (x86_pmu.put_event_constraints) + x86_pmu.put_event_constraints(fake_cpuc, event); + + kfree(fake_cpuc); + + return ret; +} + /* * validate a single event group * @@ -1529,6 +1460,8 @@ const struct pmu *hw_perf_event_init(struct perf_event *event) if (event->group_leader != event) err = validate_group(event); + else + err = validate_event(event); event->pmu = tmp; } diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 84bfde64a33..11446412e4c 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -470,42 +470,6 @@ static u64 intel_pmu_raw_event(u64 hw_event) return hw_event & CORE_EVNTSEL_MASK; } -static void intel_pmu_enable_bts(u64 config) -{ - unsigned long debugctlmsr; - - debugctlmsr = get_debugctlmsr(); - - debugctlmsr |= X86_DEBUGCTL_TR; - debugctlmsr |= X86_DEBUGCTL_BTS; - debugctlmsr |= X86_DEBUGCTL_BTINT; - - if (!(config & ARCH_PERFMON_EVENTSEL_OS)) - debugctlmsr |= X86_DEBUGCTL_BTS_OFF_OS; - - if (!(config & ARCH_PERFMON_EVENTSEL_USR)) - debugctlmsr |= X86_DEBUGCTL_BTS_OFF_USR; - - update_debugctlmsr(debugctlmsr); -} - -static void intel_pmu_disable_bts(void) -{ - struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); - unsigned long debugctlmsr; - - if (!cpuc->ds) - return; - - debugctlmsr = get_debugctlmsr(); - - debugctlmsr &= - ~(X86_DEBUGCTL_TR | X86_DEBUGCTL_BTS | X86_DEBUGCTL_BTINT | - X86_DEBUGCTL_BTS_OFF_OS | X86_DEBUGCTL_BTS_OFF_USR); - - update_debugctlmsr(debugctlmsr); -} - static void intel_pmu_disable_all(void) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); @@ -514,6 +478,8 @@ static void intel_pmu_disable_all(void) if (test_bit(X86_PMC_IDX_FIXED_BTS, cpuc->active_mask)) intel_pmu_disable_bts(); + + intel_pmu_pebs_disable_all(); } static void intel_pmu_enable_all(void) @@ -531,6 +497,8 @@ static void intel_pmu_enable_all(void) intel_pmu_enable_bts(event->hw.config); } + + intel_pmu_pebs_enable_all(); } static inline u64 intel_pmu_get_status(void) @@ -547,8 +515,7 @@ static inline void intel_pmu_ack_status(u64 ack) wrmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, ack); } -static inline void -intel_pmu_disable_fixed(struct hw_perf_event *hwc) +static void intel_pmu_disable_fixed(struct hw_perf_event *hwc) { int idx = hwc->idx - X86_PMC_IDX_FIXED; u64 ctrl_val, mask; @@ -560,68 +527,7 @@ intel_pmu_disable_fixed(struct hw_perf_event *hwc) (void)checking_wrmsrl(hwc->config_base, ctrl_val); } -static void intel_pmu_drain_bts_buffer(void) -{ - struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); - struct debug_store *ds = cpuc->ds; - struct bts_record { - u64 from; - u64 to; - u64 flags; - }; - struct perf_event *event = cpuc->events[X86_PMC_IDX_FIXED_BTS]; - struct bts_record *at, *top; - struct perf_output_handle handle; - struct perf_event_header header; - struct perf_sample_data data; - struct pt_regs regs; - - if (!event) - return; - - if (!ds) - return; - - at = (struct bts_record *)(unsigned long)ds->bts_buffer_base; - top = (struct bts_record *)(unsigned long)ds->bts_index; - - if (top <= at) - return; - - ds->bts_index = ds->bts_buffer_base; - - perf_sample_data_init(&data, 0); - - data.period = event->hw.last_period; - regs.ip = 0; - - /* - * Prepare a generic sample, i.e. fill in the invariant fields. - * We will overwrite the from and to address before we output - * the sample. - */ - perf_prepare_sample(&header, &data, event, ®s); - - if (perf_output_begin(&handle, event, - header.size * (top - at), 1, 1)) - return; - - for (; at < top; at++) { - data.ip = at->from; - data.addr = at->to; - - perf_output_sample(&handle, &header, &data, event); - } - - perf_output_end(&handle); - - /* There's new data available. */ - event->hw.interrupts++; - event->pending_kill = POLL_IN; -} - -static inline void -intel_pmu_disable_event(struct perf_event *event) +static void intel_pmu_disable_event(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; @@ -637,10 +543,12 @@ intel_pmu_disable_event(struct perf_event *event) } x86_pmu_disable_event(event); + + if (unlikely(event->attr.precise)) + intel_pmu_pebs_disable(hwc); } -static inline void -intel_pmu_enable_fixed(struct hw_perf_event *hwc) +static void intel_pmu_enable_fixed(struct hw_perf_event *hwc) { int idx = hwc->idx - X86_PMC_IDX_FIXED; u64 ctrl_val, bits, mask; @@ -689,6 +597,9 @@ static void intel_pmu_enable_event(struct perf_event *event) return; } + if (unlikely(event->attr.precise)) + intel_pmu_pebs_enable(hwc); + __x86_pmu_enable_event(hwc); } @@ -762,6 +673,13 @@ again: inc_irq_stat(apic_perf_irqs); ack = status; + + /* + * PEBS overflow sets bit 62 in the global status register + */ + if (__test_and_clear_bit(62, (unsigned long *)&status)) + x86_pmu.drain_pebs(regs); + for_each_set_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) { struct perf_event *event = cpuc->events[bit]; @@ -791,22 +709,18 @@ done: return 1; } -static struct event_constraint bts_constraint = - EVENT_CONSTRAINT(0, 1ULL << X86_PMC_IDX_FIXED_BTS, 0); - static struct event_constraint * -intel_special_constraints(struct perf_event *event) +intel_bts_constraints(struct perf_event *event) { - unsigned int hw_event; - - hw_event = event->hw.config & INTEL_ARCH_EVENT_MASK; + struct hw_perf_event *hwc = &event->hw; + unsigned int hw_event, bts_event; - if (unlikely((hw_event == - x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS)) && - (event->hw.sample_period == 1))) { + hw_event = hwc->config & INTEL_ARCH_EVENT_MASK; + bts_event = x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS); + if (unlikely(hw_event == bts_event && hwc->sample_period == 1)) return &bts_constraint; - } + return NULL; } @@ -815,7 +729,11 @@ intel_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event { struct event_constraint *c; - c = intel_special_constraints(event); + c = intel_bts_constraints(event); + if (c) + return c; + + c = intel_pebs_constraints(event); if (c) return c; @@ -864,8 +782,6 @@ static __initconst struct x86_pmu intel_pmu = { * the generic event period: */ .max_period = (1ULL << 31) - 1, - .enable_bts = intel_pmu_enable_bts, - .disable_bts = intel_pmu_disable_bts, .get_event_constraints = intel_get_event_constraints, .cpu_starting = init_debug_store_on_cpu, @@ -915,6 +831,8 @@ static __init int intel_pmu_init(void) if (version > 1) x86_pmu.num_events_fixed = max((int)edx.split.num_events_fixed, 3); + intel_ds_init(); + /* * Install the hw-cache-events table: */ diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c new file mode 100644 index 00000000000..0d994ef213b --- /dev/null +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -0,0 +1,557 @@ +#ifdef CONFIG_CPU_SUP_INTEL + +/* The maximal number of PEBS events: */ +#define MAX_PEBS_EVENTS 4 + +/* The size of a BTS record in bytes: */ +#define BTS_RECORD_SIZE 24 + +#define BTS_BUFFER_SIZE (PAGE_SIZE << 4) +#define PEBS_BUFFER_SIZE PAGE_SIZE + +/* + * pebs_record_32 for p4 and core not supported + +struct pebs_record_32 { + u32 flags, ip; + u32 ax, bc, cx, dx; + u32 si, di, bp, sp; +}; + + */ + +struct pebs_record_core { + u64 flags, ip; + u64 ax, bx, cx, dx; + u64 si, di, bp, sp; + u64 r8, r9, r10, r11; + u64 r12, r13, r14, r15; +}; + +struct pebs_record_nhm { + u64 flags, ip; + u64 ax, bx, cx, dx; + u64 si, di, bp, sp; + u64 r8, r9, r10, r11; + u64 r12, r13, r14, r15; + u64 status, dla, dse, lat; +}; + +/* + * Bits in the debugctlmsr controlling branch tracing. + */ +#define X86_DEBUGCTL_TR (1 << 6) +#define X86_DEBUGCTL_BTS (1 << 7) +#define X86_DEBUGCTL_BTINT (1 << 8) +#define X86_DEBUGCTL_BTS_OFF_OS (1 << 9) +#define X86_DEBUGCTL_BTS_OFF_USR (1 << 10) + +/* + * A debug store configuration. + * + * We only support architectures that use 64bit fields. + */ +struct debug_store { + u64 bts_buffer_base; + u64 bts_index; + u64 bts_absolute_maximum; + u64 bts_interrupt_threshold; + u64 pebs_buffer_base; + u64 pebs_index; + u64 pebs_absolute_maximum; + u64 pebs_interrupt_threshold; + u64 pebs_event_reset[MAX_PEBS_EVENTS]; +}; + +static void init_debug_store_on_cpu(int cpu) +{ + struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; + + if (!ds) + return; + + wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, + (u32)((u64)(unsigned long)ds), + (u32)((u64)(unsigned long)ds >> 32)); +} + +static void fini_debug_store_on_cpu(int cpu) +{ + if (!per_cpu(cpu_hw_events, cpu).ds) + return; + + wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0); +} + +static void release_ds_buffers(void) +{ + int cpu; + + if (!x86_pmu.bts && !x86_pmu.pebs) + return; + + get_online_cpus(); + + for_each_online_cpu(cpu) + fini_debug_store_on_cpu(cpu); + + for_each_possible_cpu(cpu) { + struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; + + if (!ds) + continue; + + per_cpu(cpu_hw_events, cpu).ds = NULL; + + kfree((void *)(unsigned long)ds->pebs_buffer_base); + kfree((void *)(unsigned long)ds->bts_buffer_base); + kfree(ds); + } + + put_online_cpus(); +} + +static int reserve_ds_buffers(void) +{ + int cpu, err = 0; + + if (!x86_pmu.bts && !x86_pmu.pebs) + return 0; + + get_online_cpus(); + + for_each_possible_cpu(cpu) { + struct debug_store *ds; + void *buffer; + int max, thresh; + + err = -ENOMEM; + ds = kzalloc(sizeof(*ds), GFP_KERNEL); + if (unlikely(!ds)) { + kfree(buffer); + break; + } + per_cpu(cpu_hw_events, cpu).ds = ds; + + if (x86_pmu.bts) { + buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL); + if (unlikely(!buffer)) + break; + + max = BTS_BUFFER_SIZE / BTS_RECORD_SIZE; + thresh = max / 16; + + ds->bts_buffer_base = (u64)(unsigned long)buffer; + ds->bts_index = ds->bts_buffer_base; + ds->bts_absolute_maximum = ds->bts_buffer_base + + max * BTS_RECORD_SIZE; + ds->bts_interrupt_threshold = ds->bts_absolute_maximum - + thresh * BTS_RECORD_SIZE; + } + + if (x86_pmu.pebs) { + buffer = kzalloc(PEBS_BUFFER_SIZE, GFP_KERNEL); + if (unlikely(!buffer)) + break; + + max = PEBS_BUFFER_SIZE / x86_pmu.pebs_record_size; + + ds->pebs_buffer_base = (u64)(unsigned long)buffer; + ds->pebs_index = ds->pebs_buffer_base; + ds->pebs_absolute_maximum = ds->pebs_buffer_base + + max * x86_pmu.pebs_record_size; + /* + * Always use single record PEBS + */ + ds->pebs_interrupt_threshold = ds->pebs_buffer_base + + x86_pmu.pebs_record_size; + } + + err = 0; + } + + if (err) + release_ds_buffers(); + else { + for_each_online_cpu(cpu) + init_debug_store_on_cpu(cpu); + } + + put_online_cpus(); + + return err; +} + +/* + * BTS + */ + +static struct event_constraint bts_constraint = + EVENT_CONSTRAINT(0, 1ULL << X86_PMC_IDX_FIXED_BTS, 0); + +static void intel_pmu_enable_bts(u64 config) +{ + unsigned long debugctlmsr; + + debugctlmsr = get_debugctlmsr(); + + debugctlmsr |= X86_DEBUGCTL_TR; + debugctlmsr |= X86_DEBUGCTL_BTS; + debugctlmsr |= X86_DEBUGCTL_BTINT; + + if (!(config & ARCH_PERFMON_EVENTSEL_OS)) + debugctlmsr |= X86_DEBUGCTL_BTS_OFF_OS; + + if (!(config & ARCH_PERFMON_EVENTSEL_USR)) + debugctlmsr |= X86_DEBUGCTL_BTS_OFF_USR; + + update_debugctlmsr(debugctlmsr); +} + +static void intel_pmu_disable_bts(void) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + unsigned long debugctlmsr; + + if (!cpuc->ds) + return; + + debugctlmsr = get_debugctlmsr(); + + debugctlmsr &= + ~(X86_DEBUGCTL_TR | X86_DEBUGCTL_BTS | X86_DEBUGCTL_BTINT | + X86_DEBUGCTL_BTS_OFF_OS | X86_DEBUGCTL_BTS_OFF_USR); + + update_debugctlmsr(debugctlmsr); +} + +static void intel_pmu_drain_bts_buffer(void) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct debug_store *ds = cpuc->ds; + struct bts_record { + u64 from; + u64 to; + u64 flags; + }; + struct perf_event *event = cpuc->events[X86_PMC_IDX_FIXED_BTS]; + struct bts_record *at, *top; + struct perf_output_handle handle; + struct perf_event_header header; + struct perf_sample_data data; + struct pt_regs regs; + + if (!event) + return; + + if (!ds) + return; + + at = (struct bts_record *)(unsigned long)ds->bts_buffer_base; + top = (struct bts_record *)(unsigned long)ds->bts_index; + + if (top <= at) + return; + + ds->bts_index = ds->bts_buffer_base; + + perf_sample_data_init(&data, 0); + data.period = event->hw.last_period; + regs.ip = 0; + + /* + * Prepare a generic sample, i.e. fill in the invariant fields. + * We will overwrite the from and to address before we output + * the sample. + */ + perf_prepare_sample(&header, &data, event, ®s); + + if (perf_output_begin(&handle, event, header.size * (top - at), 1, 1)) + return; + + for (; at < top; at++) { + data.ip = at->from; + data.addr = at->to; + + perf_output_sample(&handle, &header, &data, event); + } + + perf_output_end(&handle); + + /* There's new data available. */ + event->hw.interrupts++; + event->pending_kill = POLL_IN; +} + +/* + * PEBS + */ + +static struct event_constraint intel_core_pebs_events[] = { + PEBS_EVENT_CONSTRAINT(0x00c0, 0x1), /* INSTR_RETIRED.ANY */ + PEBS_EVENT_CONSTRAINT(0xfec1, 0x1), /* X87_OPS_RETIRED.ANY */ + PEBS_EVENT_CONSTRAINT(0x00c5, 0x1), /* BR_INST_RETIRED.MISPRED */ + PEBS_EVENT_CONSTRAINT(0x1fc7, 0x1), /* SIMD_INST_RETURED.ANY */ + PEBS_EVENT_CONSTRAINT(0x01cb, 0x1), /* MEM_LOAD_RETIRED.L1D_MISS */ + PEBS_EVENT_CONSTRAINT(0x02cb, 0x1), /* MEM_LOAD_RETIRED.L1D_LINE_MISS */ + PEBS_EVENT_CONSTRAINT(0x04cb, 0x1), /* MEM_LOAD_RETIRED.L2_MISS */ + PEBS_EVENT_CONSTRAINT(0x08cb, 0x1), /* MEM_LOAD_RETIRED.L2_LINE_MISS */ + PEBS_EVENT_CONSTRAINT(0x10cb, 0x1), /* MEM_LOAD_RETIRED.DTLB_MISS */ + EVENT_CONSTRAINT_END +}; + +static struct event_constraint intel_nehalem_pebs_events[] = { + PEBS_EVENT_CONSTRAINT(0x00c0, 0xf), /* INSTR_RETIRED.ANY */ + PEBS_EVENT_CONSTRAINT(0xfec1, 0xf), /* X87_OPS_RETIRED.ANY */ + PEBS_EVENT_CONSTRAINT(0x00c5, 0xf), /* BR_INST_RETIRED.MISPRED */ + PEBS_EVENT_CONSTRAINT(0x1fc7, 0xf), /* SIMD_INST_RETURED.ANY */ + PEBS_EVENT_CONSTRAINT(0x01cb, 0xf), /* MEM_LOAD_RETIRED.L1D_MISS */ + PEBS_EVENT_CONSTRAINT(0x02cb, 0xf), /* MEM_LOAD_RETIRED.L1D_LINE_MISS */ + PEBS_EVENT_CONSTRAINT(0x04cb, 0xf), /* MEM_LOAD_RETIRED.L2_MISS */ + PEBS_EVENT_CONSTRAINT(0x08cb, 0xf), /* MEM_LOAD_RETIRED.L2_LINE_MISS */ + PEBS_EVENT_CONSTRAINT(0x10cb, 0xf), /* MEM_LOAD_RETIRED.DTLB_MISS */ + EVENT_CONSTRAINT_END +}; + +static struct event_constraint * +intel_pebs_constraints(struct perf_event *event) +{ + struct event_constraint *c; + + if (!event->attr.precise) + return NULL; + + if (x86_pmu.pebs_constraints) { + for_each_event_constraint(c, x86_pmu.pebs_constraints) { + if ((event->hw.config & c->cmask) == c->code) + return c; + } + } + + return &emptyconstraint; +} + +static void intel_pmu_pebs_enable(struct hw_perf_event *hwc) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + u64 val = cpuc->pebs_enabled; + + hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT; + + val |= 1ULL << hwc->idx; + wrmsrl(MSR_IA32_PEBS_ENABLE, val); +} + +static void intel_pmu_pebs_disable(struct hw_perf_event *hwc) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + u64 val = cpuc->pebs_enabled; + + val &= ~(1ULL << hwc->idx); + wrmsrl(MSR_IA32_PEBS_ENABLE, val); + + hwc->config |= ARCH_PERFMON_EVENTSEL_INT; +} + +static void intel_pmu_pebs_enable_all(void) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + + if (cpuc->pebs_enabled) + wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled); +} + +static void intel_pmu_pebs_disable_all(void) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + + if (cpuc->pebs_enabled) + wrmsrl(MSR_IA32_PEBS_ENABLE, 0); +} + +static int intel_pmu_save_and_restart(struct perf_event *event); +static void intel_pmu_disable_event(struct perf_event *event); + +static void intel_pmu_drain_pebs_core(struct pt_regs *iregs) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct debug_store *ds = cpuc->ds; + struct perf_event *event = cpuc->events[0]; /* PMC0 only */ + struct pebs_record_core *at, *top; + struct perf_sample_data data; + struct pt_regs regs; + int n; + + if (!event || !ds || !x86_pmu.pebs) + return; + + intel_pmu_pebs_disable_all(); + + at = (struct pebs_record_core *)(unsigned long)ds->pebs_buffer_base; + top = (struct pebs_record_core *)(unsigned long)ds->pebs_index; + + if (top <= at) + goto out; + + ds->pebs_index = ds->pebs_buffer_base; + + if (!intel_pmu_save_and_restart(event)) + goto out; + + perf_sample_data_init(&data, 0); + data.period = event->hw.last_period; + + n = top - at; + + /* + * Should not happen, we program the threshold at 1 and do not + * set a reset value. + */ + WARN_ON_ONCE(n > 1); + + /* + * We use the interrupt regs as a base because the PEBS record + * does not contain a full regs set, specifically it seems to + * lack segment descriptors, which get used by things like + * user_mode(). + * + * In the simple case fix up only the IP and BP,SP regs, for + * PERF_SAMPLE_IP and PERF_SAMPLE_CALLCHAIN to function properly. + * A possible PERF_SAMPLE_REGS will have to transfer all regs. + */ + regs = *iregs; + regs.ip = at->ip; + regs.bp = at->bp; + regs.sp = at->sp; + + if (perf_event_overflow(event, 1, &data, ®s)) + intel_pmu_disable_event(event); + +out: + intel_pmu_pebs_enable_all(); +} + +static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct debug_store *ds = cpuc->ds; + struct pebs_record_nhm *at, *top; + struct perf_sample_data data; + struct perf_event *event = NULL; + struct pt_regs regs; + int bit, n; + + if (!ds || !x86_pmu.pebs) + return; + + intel_pmu_pebs_disable_all(); + + at = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base; + top = (struct pebs_record_nhm *)(unsigned long)ds->pebs_index; + + if (top <= at) + goto out; + + ds->pebs_index = ds->pebs_buffer_base; + + n = top - at; + + /* + * Should not happen, we program the threshold at 1 and do not + * set a reset value. + */ + WARN_ON_ONCE(n > MAX_PEBS_EVENTS); + + for ( ; at < top; at++) { + for_each_bit(bit, (unsigned long *)&at->status, MAX_PEBS_EVENTS) { + if (!cpuc->events[bit]->attr.precise) + continue; + + event = cpuc->events[bit]; + } + + if (!event) + continue; + + if (!intel_pmu_save_and_restart(event)) + continue; + + perf_sample_data_init(&data, 0); + data.period = event->hw.last_period; + + /* + * See the comment in intel_pmu_drain_pebs_core() + */ + regs = *iregs; + regs.ip = at->ip; + regs.bp = at->bp; + regs.sp = at->sp; + + if (perf_event_overflow(event, 1, &data, ®s)) + intel_pmu_disable_event(event); + } +out: + intel_pmu_pebs_enable_all(); +} + +/* + * BTS, PEBS probe and setup + */ + +static void intel_ds_init(void) +{ + /* + * No support for 32bit formats + */ + if (!boot_cpu_has(X86_FEATURE_DTES64)) + return; + + x86_pmu.bts = boot_cpu_has(X86_FEATURE_BTS); + x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS); + if (x86_pmu.pebs) { + int format = 0; + + if (x86_pmu.version > 1) { + u64 capabilities; + /* + * v2+ has a PEBS format field + */ + rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities); + format = (capabilities >> 8) & 0xf; + } + + switch (format) { + case 0: + printk(KERN_CONT "PEBS v0, "); + x86_pmu.pebs_record_size = sizeof(struct pebs_record_core); + x86_pmu.drain_pebs = intel_pmu_drain_pebs_core; + x86_pmu.pebs_constraints = intel_core_pebs_events; + break; + + case 1: + printk(KERN_CONT "PEBS v1, "); + x86_pmu.pebs_record_size = sizeof(struct pebs_record_nhm); + x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm; + x86_pmu.pebs_constraints = intel_nehalem_pebs_events; + break; + + default: + printk(KERN_CONT "PEBS unknown format: %d, ", format); + x86_pmu.pebs = 0; + break; + } + } +} + +#else /* CONFIG_CPU_SUP_INTEL */ + +static int reseve_ds_buffers(void) +{ + return 0; +} + +static void release_ds_buffers(void) +{ +} + +#endif /* CONFIG_CPU_SUP_INTEL */ diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 80acbf3d5de..42307b50c78 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -203,8 +203,9 @@ struct perf_event_attr { enable_on_exec : 1, /* next exec enables */ task : 1, /* trace fork/exit */ watermark : 1, /* wakeup_watermark */ + precise : 1, /* OoO invariant counter */ - __reserved_1 : 49; + __reserved_1 : 48; union { __u32 wakeup_events; /* wakeup every n events */ -- cgit v1.2.3-70-g09d2 From caff2befffe899e63df5cc760b7ed01cfd902685 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 3 Mar 2010 12:02:30 +0100 Subject: perf, x86: Implement simple LBR support Implement simple suport Intel Last-Branch-Record, it supports all hardware that implements FREEZE_LBRS_ON_PMI, but does not (yet) implement the LBR config register. The Intel LBR is a FIFO of From,To addresses describing the last few branches the hardware took. This patch does not add perf interface to the LBR, but merely provides an interface for internal use. Signed-off-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: paulus@samba.org Cc: eranian@google.com Cc: robert.richter@amd.com Cc: fweisbec@gmail.com LKML-Reference: <20100304140100.544191154@chello.nl> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.c | 18 +++ arch/x86/kernel/cpu/perf_event_intel.c | 13 ++ arch/x86/kernel/cpu/perf_event_intel_lbr.c | 228 +++++++++++++++++++++++++++++ include/linux/perf_event.h | 11 ++ 4 files changed, 270 insertions(+) create mode 100644 arch/x86/kernel/cpu/perf_event_intel_lbr.c (limited to 'include') diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 0c03d5c1671..1badff6b6b2 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -48,6 +48,8 @@ struct amd_nb { struct event_constraint event_constraints[X86_PMC_IDX_MAX]; }; +#define MAX_LBR_ENTRIES 16 + struct cpu_hw_events { /* * Generic x86 PMC bits @@ -69,6 +71,14 @@ struct cpu_hw_events { struct debug_store *ds; u64 pebs_enabled; + /* + * Intel LBR bits + */ + int lbr_users; + void *lbr_context; + struct perf_branch_stack lbr_stack; + struct perf_branch_entry lbr_entries[MAX_LBR_ENTRIES]; + /* * AMD specific bits */ @@ -159,6 +169,13 @@ struct x86_pmu { int pebs_record_size; void (*drain_pebs)(struct pt_regs *regs); struct event_constraint *pebs_constraints; + + /* + * Intel LBR + */ + unsigned long lbr_tos, lbr_from, lbr_to; /* MSR base regs */ + int lbr_nr; /* hardware stack size */ + int lbr_format; /* hardware format */ }; static struct x86_pmu x86_pmu __read_mostly; @@ -1237,6 +1254,7 @@ undo: #include "perf_event_amd.c" #include "perf_event_p6.c" +#include "perf_event_intel_lbr.c" #include "perf_event_intel_ds.c" #include "perf_event_intel.c" diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 11446412e4c..44f6ed42a93 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -480,6 +480,7 @@ static void intel_pmu_disable_all(void) intel_pmu_disable_bts(); intel_pmu_pebs_disable_all(); + intel_pmu_lbr_disable_all(); } static void intel_pmu_enable_all(void) @@ -499,6 +500,7 @@ static void intel_pmu_enable_all(void) } intel_pmu_pebs_enable_all(); + intel_pmu_lbr_enable_all(); } static inline u64 intel_pmu_get_status(void) @@ -674,6 +676,8 @@ again: inc_irq_stat(apic_perf_irqs); ack = status; + intel_pmu_lbr_read(); + /* * PEBS overflow sets bit 62 in the global status register */ @@ -848,6 +852,8 @@ static __init int intel_pmu_init(void) memcpy(hw_cache_event_ids, core2_hw_cache_event_ids, sizeof(hw_cache_event_ids)); + intel_pmu_lbr_init_core(); + x86_pmu.event_constraints = intel_core2_event_constraints; pr_cont("Core2 events, "); break; @@ -857,13 +863,18 @@ static __init int intel_pmu_init(void) memcpy(hw_cache_event_ids, nehalem_hw_cache_event_ids, sizeof(hw_cache_event_ids)); + intel_pmu_lbr_init_nhm(); + x86_pmu.event_constraints = intel_nehalem_event_constraints; pr_cont("Nehalem/Corei7 events, "); break; + case 28: /* Atom */ memcpy(hw_cache_event_ids, atom_hw_cache_event_ids, sizeof(hw_cache_event_ids)); + intel_pmu_lbr_init_atom(); + x86_pmu.event_constraints = intel_gen_event_constraints; pr_cont("Atom events, "); break; @@ -873,6 +884,8 @@ static __init int intel_pmu_init(void) memcpy(hw_cache_event_ids, westmere_hw_cache_event_ids, sizeof(hw_cache_event_ids)); + intel_pmu_lbr_init_nhm(); + x86_pmu.event_constraints = intel_westmere_event_constraints; pr_cont("Westmere events, "); break; diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c new file mode 100644 index 00000000000..ea3e99ed82c --- /dev/null +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c @@ -0,0 +1,228 @@ +#ifdef CONFIG_CPU_SUP_INTEL + +enum { + LBR_FORMAT_32 = 0x00, + LBR_FORMAT_LIP = 0x01, + LBR_FORMAT_EIP = 0x02, + LBR_FORMAT_EIP_FLAGS = 0x03, +}; + +/* + * We only support LBR implementations that have FREEZE_LBRS_ON_PMI + * otherwise it becomes near impossible to get a reliable stack. + */ + +#define X86_DEBUGCTL_LBR (1 << 0) +#define X86_DEBUGCTL_FREEZE_LBRS_ON_PMI (1 << 11) + +static void __intel_pmu_lbr_enable(void) +{ + u64 debugctl; + + rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); + debugctl |= (X86_DEBUGCTL_LBR | X86_DEBUGCTL_FREEZE_LBRS_ON_PMI); + wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); +} + +static void __intel_pmu_lbr_disable(void) +{ + u64 debugctl; + + rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); + debugctl &= ~(X86_DEBUGCTL_LBR | X86_DEBUGCTL_FREEZE_LBRS_ON_PMI); + wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); +} + +static void intel_pmu_lbr_reset_32(void) +{ + int i; + + for (i = 0; i < x86_pmu.lbr_nr; i++) + wrmsrl(x86_pmu.lbr_from + i, 0); +} + +static void intel_pmu_lbr_reset_64(void) +{ + int i; + + for (i = 0; i < x86_pmu.lbr_nr; i++) { + wrmsrl(x86_pmu.lbr_from + i, 0); + wrmsrl(x86_pmu.lbr_to + i, 0); + } +} + +static void intel_pmu_lbr_reset(void) +{ + if (x86_pmu.lbr_format == LBR_FORMAT_32) + intel_pmu_lbr_reset_32(); + else + intel_pmu_lbr_reset_64(); +} + +static void intel_pmu_lbr_enable(struct perf_event *event) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + + if (!x86_pmu.lbr_nr) + return; + + WARN_ON(cpuc->enabled); + + /* + * Reset the LBR stack if this is the first LBR user or + * we changed task context so as to avoid data leaks. + */ + + if (!cpuc->lbr_users || + (event->ctx->task && cpuc->lbr_context != event->ctx)) { + intel_pmu_lbr_reset(); + cpuc->lbr_context = event->ctx; + } + + cpuc->lbr_users++; +} + +static void intel_pmu_lbr_disable(struct perf_event *event) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + + if (!x86_pmu.lbr_nr) + return; + + cpuc->lbr_users--; + + BUG_ON(cpuc->lbr_users < 0); + WARN_ON(cpuc->enabled); +} + +static void intel_pmu_lbr_enable_all(void) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + + if (cpuc->lbr_users) + __intel_pmu_lbr_enable(); +} + +static void intel_pmu_lbr_disable_all(void) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + + if (cpuc->lbr_users) + __intel_pmu_lbr_disable(); +} + +static inline u64 intel_pmu_lbr_tos(void) +{ + u64 tos; + + rdmsrl(x86_pmu.lbr_tos, tos); + + return tos; +} + +static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc) +{ + unsigned long mask = x86_pmu.lbr_nr - 1; + u64 tos = intel_pmu_lbr_tos(); + int i; + + for (i = 0; i < x86_pmu.lbr_nr; i++, tos--) { + unsigned long lbr_idx = (tos - i) & mask; + union { + struct { + u32 from; + u32 to; + }; + u64 lbr; + } msr_lastbranch; + + rdmsrl(x86_pmu.lbr_from + lbr_idx, msr_lastbranch.lbr); + + cpuc->lbr_entries[i].from = msr_lastbranch.from; + cpuc->lbr_entries[i].to = msr_lastbranch.to; + cpuc->lbr_entries[i].flags = 0; + } + cpuc->lbr_stack.nr = i; +} + +#define LBR_FROM_FLAG_MISPRED (1ULL << 63) + +/* + * Due to lack of segmentation in Linux the effective address (offset) + * is the same as the linear address, allowing us to merge the LIP and EIP + * LBR formats. + */ +static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc) +{ + unsigned long mask = x86_pmu.lbr_nr - 1; + u64 tos = intel_pmu_lbr_tos(); + int i; + + for (i = 0; i < x86_pmu.lbr_nr; i++, tos--) { + unsigned long lbr_idx = (tos - i) & mask; + u64 from, to, flags = 0; + + rdmsrl(x86_pmu.lbr_from + lbr_idx, from); + rdmsrl(x86_pmu.lbr_to + lbr_idx, to); + + if (x86_pmu.lbr_format == LBR_FORMAT_EIP_FLAGS) { + flags = !!(from & LBR_FROM_FLAG_MISPRED); + from = (u64)((((s64)from) << 1) >> 1); + } + + cpuc->lbr_entries[i].from = from; + cpuc->lbr_entries[i].to = to; + cpuc->lbr_entries[i].flags = flags; + } + cpuc->lbr_stack.nr = i; +} + +static void intel_pmu_lbr_read(void) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + + if (!cpuc->lbr_users) + return; + + if (x86_pmu.lbr_format == LBR_FORMAT_32) + intel_pmu_lbr_read_32(cpuc); + else + intel_pmu_lbr_read_64(cpuc); +} + +static int intel_pmu_lbr_format(void) +{ + u64 capabilities; + + rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities); + return capabilities & 0x1f; +} + +static void intel_pmu_lbr_init_core(void) +{ + x86_pmu.lbr_format = intel_pmu_lbr_format(); + x86_pmu.lbr_nr = 4; + x86_pmu.lbr_tos = 0x01c9; + x86_pmu.lbr_from = 0x40; + x86_pmu.lbr_to = 0x60; +} + +static void intel_pmu_lbr_init_nhm(void) +{ + x86_pmu.lbr_format = intel_pmu_lbr_format(); + x86_pmu.lbr_nr = 16; + x86_pmu.lbr_tos = 0x01c9; + x86_pmu.lbr_from = 0x680; + x86_pmu.lbr_to = 0x6c0; +} + +static void intel_pmu_lbr_init_atom(void) +{ + x86_pmu.lbr_format = intel_pmu_lbr_format(); + x86_pmu.lbr_nr = 8; + x86_pmu.lbr_tos = 0x01c9; + x86_pmu.lbr_from = 0x40; + x86_pmu.lbr_to = 0x60; +} + +#endif /* CONFIG_CPU_SUP_INTEL */ diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 42307b50c78..ab4fd9ede26 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -467,6 +467,17 @@ struct perf_raw_record { void *data; }; +struct perf_branch_entry { + __u64 from; + __u64 to; + __u64 flags; +}; + +struct perf_branch_stack { + __u64 nr; + struct perf_branch_entry entries[0]; +}; + struct task_struct; /** -- cgit v1.2.3-70-g09d2 From ef21f683a045a79b6aa86ad81e5fdfc0d5ddd250 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 3 Mar 2010 13:12:23 +0100 Subject: perf, x86: use LBR for PEBS IP+1 fixup Use the LBR to fix up the PEBS IP+1 issue. As said, PEBS reports the next instruction, here we use the LBR to find the last branch and from that construct the actual IP. If the IP matches the LBR-TO, we use LBR-FROM, otherwise we use the LBR-TO address as the beginning of the last basic block and decode forward. Once we find a match to the current IP, we use the previous location. This patch introduces a new ABI element: PERF_RECORD_MISC_EXACT, which conveys that the reported IP (PERF_SAMPLE_IP) is the exact instruction that caused the event (barring CPU errata). The fixup can fail due to various reasons: 1) LBR contains invalid data (quite possible) 2) part of the basic block got paged out 3) the reported IP isn't part of the basic block (see 1) Signed-off-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Masami Hiramatsu Cc: "Zhang, Yanmin" Cc: paulus@samba.org Cc: eranian@google.com Cc: robert.richter@amd.com Cc: fweisbec@gmail.com LKML-Reference: <20100304140100.619375431@chello.nl> Signed-off-by: Ingo Molnar --- arch/x86/include/asm/perf_event.h | 19 +++++++ arch/x86/kernel/cpu/perf_event.c | 70 +++++++++++++------------- arch/x86/kernel/cpu/perf_event_intel.c | 4 +- arch/x86/kernel/cpu/perf_event_intel_ds.c | 84 ++++++++++++++++++++++++++++++- include/linux/perf_event.h | 6 +++ 5 files changed, 144 insertions(+), 39 deletions(-) (limited to 'include') diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index db6109a885a..a9038c95161 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -136,6 +136,25 @@ extern void perf_events_lapic_init(void); #define PERF_EVENT_INDEX_OFFSET 0 +/* + * Abuse bit 3 of the cpu eflags register to indicate proper PEBS IP fixups. + * This flag is otherwise unused and ABI specified to be 0, so nobody should + * care what we do with it. + */ +#define PERF_EFLAGS_EXACT (1UL << 3) + +#define perf_misc_flags(regs) \ +({ int misc = 0; \ + if (user_mode(regs)) \ + misc |= PERF_RECORD_MISC_USER; \ + else \ + misc |= PERF_RECORD_MISC_KERNEL; \ + if (regs->flags & PERF_EFLAGS_EXACT) \ + misc |= PERF_RECORD_MISC_EXACT; \ + misc; }) + +#define perf_instruction_pointer(regs) ((regs)->ip) + #else static inline void init_hw_perf_events(void) { } static inline void perf_events_lapic_init(void) { } diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 1badff6b6b2..5cb4e8dcee4 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -29,6 +29,41 @@ #include #include +/* + * best effort, GUP based copy_from_user() that assumes IRQ or NMI context + */ +static unsigned long +copy_from_user_nmi(void *to, const void __user *from, unsigned long n) +{ + unsigned long offset, addr = (unsigned long)from; + int type = in_nmi() ? KM_NMI : KM_IRQ0; + unsigned long size, len = 0; + struct page *page; + void *map; + int ret; + + do { + ret = __get_user_pages_fast(addr, 1, 0, &page); + if (!ret) + break; + + offset = addr & (PAGE_SIZE - 1); + size = min(PAGE_SIZE - offset, n - len); + + map = kmap_atomic(page, type); + memcpy(to, map+offset, size); + kunmap_atomic(map, type); + put_page(page); + + len += size; + to += size; + addr += size; + + } while (len < n); + + return len; +} + static u64 perf_event_mask __read_mostly; struct event_constraint { @@ -1550,41 +1585,6 @@ perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry) dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry); } -/* - * best effort, GUP based copy_from_user() that assumes IRQ or NMI context - */ -static unsigned long -copy_from_user_nmi(void *to, const void __user *from, unsigned long n) -{ - unsigned long offset, addr = (unsigned long)from; - int type = in_nmi() ? KM_NMI : KM_IRQ0; - unsigned long size, len = 0; - struct page *page; - void *map; - int ret; - - do { - ret = __get_user_pages_fast(addr, 1, 0, &page); - if (!ret) - break; - - offset = addr & (PAGE_SIZE - 1); - size = min(PAGE_SIZE - offset, n - len); - - map = kmap_atomic(page, type); - memcpy(to, map+offset, size); - kunmap_atomic(map, type); - put_page(page); - - len += size; - to += size; - addr += size; - - } while (len < n); - - return len; -} - static int copy_stack_frame(const void __user *fp, struct stack_frame *frame) { unsigned long bytes; diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 44f6ed42a93..7eb78be3b22 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -547,7 +547,7 @@ static void intel_pmu_disable_event(struct perf_event *event) x86_pmu_disable_event(event); if (unlikely(event->attr.precise)) - intel_pmu_pebs_disable(hwc); + intel_pmu_pebs_disable(event); } static void intel_pmu_enable_fixed(struct hw_perf_event *hwc) @@ -600,7 +600,7 @@ static void intel_pmu_enable_event(struct perf_event *event) } if (unlikely(event->attr.precise)) - intel_pmu_pebs_enable(hwc); + intel_pmu_pebs_enable(event); __x86_pmu_enable_event(hwc); } diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c index 0d994ef213b..50e6ff3281f 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -331,26 +331,32 @@ intel_pebs_constraints(struct perf_event *event) return &emptyconstraint; } -static void intel_pmu_pebs_enable(struct hw_perf_event *hwc) +static void intel_pmu_pebs_enable(struct perf_event *event) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct hw_perf_event *hwc = &event->hw; u64 val = cpuc->pebs_enabled; hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT; val |= 1ULL << hwc->idx; wrmsrl(MSR_IA32_PEBS_ENABLE, val); + + intel_pmu_lbr_enable(event); } -static void intel_pmu_pebs_disable(struct hw_perf_event *hwc) +static void intel_pmu_pebs_disable(struct perf_event *event) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct hw_perf_event *hwc = &event->hw; u64 val = cpuc->pebs_enabled; val &= ~(1ULL << hwc->idx); wrmsrl(MSR_IA32_PEBS_ENABLE, val); hwc->config |= ARCH_PERFMON_EVENTSEL_INT; + + intel_pmu_lbr_disable(event); } static void intel_pmu_pebs_enable_all(void) @@ -369,6 +375,70 @@ static void intel_pmu_pebs_disable_all(void) wrmsrl(MSR_IA32_PEBS_ENABLE, 0); } +#include + +#define MAX_INSN_SIZE 16 + +static inline bool kernel_ip(unsigned long ip) +{ +#ifdef CONFIG_X86_32 + return ip > PAGE_OFFSET; +#else + return (long)ip < 0; +#endif +} + +static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + unsigned long from = cpuc->lbr_entries[0].from; + unsigned long old_to, to = cpuc->lbr_entries[0].to; + unsigned long ip = regs->ip; + + if (!cpuc->lbr_stack.nr || !from || !to) + return 0; + + if (ip < to) + return 0; + + /* + * We sampled a branch insn, rewind using the LBR stack + */ + if (ip == to) { + regs->ip = from; + return 1; + } + + do { + struct insn insn; + u8 buf[MAX_INSN_SIZE]; + void *kaddr; + + old_to = to; + if (!kernel_ip(ip)) { + int bytes, size = min_t(int, MAX_INSN_SIZE, ip - to); + + bytes = copy_from_user_nmi(buf, (void __user *)to, size); + if (bytes != size) + return 0; + + kaddr = buf; + } else + kaddr = (void *)to; + + kernel_insn_init(&insn, kaddr); + insn_get_length(&insn); + to += insn.length; + } while (to < ip); + + if (to == ip) { + regs->ip = old_to; + return 1; + } + + return 0; +} + static int intel_pmu_save_and_restart(struct perf_event *event); static void intel_pmu_disable_event(struct perf_event *event); @@ -424,6 +494,11 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs) regs.bp = at->bp; regs.sp = at->sp; + if (intel_pmu_pebs_fixup_ip(®s)) + regs.flags |= PERF_EFLAGS_EXACT; + else + regs.flags &= ~PERF_EFLAGS_EXACT; + if (perf_event_overflow(event, 1, &data, ®s)) intel_pmu_disable_event(event); @@ -487,6 +562,11 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) regs.bp = at->bp; regs.sp = at->sp; + if (intel_pmu_pebs_fixup_ip(®s)) + regs.flags |= PERF_EFLAGS_EXACT; + else + regs.flags &= ~PERF_EFLAGS_EXACT; + if (perf_event_overflow(event, 1, &data, ®s)) intel_pmu_disable_event(event); } diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index ab4fd9ede26..be85f7c4a94 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -294,6 +294,12 @@ struct perf_event_mmap_page { #define PERF_RECORD_MISC_USER (2 << 0) #define PERF_RECORD_MISC_HYPERVISOR (3 << 0) +#define PERF_RECORD_MISC_EXACT (1 << 14) +/* + * Reserve the last bit to indicate some extended misc field + */ +#define PERF_RECORD_MISC_EXT_RESERVED (1 << 15) + struct perf_event_header { __u32 type; __u16 misc; -- cgit v1.2.3-70-g09d2 From 41acab8851a0408c1d5ad6c21a07456f88b54d40 Mon Sep 17 00:00:00 2001 From: Lucas De Marchi Date: Wed, 10 Mar 2010 23:37:45 -0300 Subject: sched: Implement group scheduler statistics in one struct Put all statistic fields of sched_entity in one struct, sched_statistics, and embed it into sched_entity. This change allows to memset the sched_statistics to 0 when needed (for instance when forking), avoiding bugs of non initialized fields. Signed-off-by: Lucas De Marchi Signed-off-by: Peter Zijlstra LKML-Reference: <1268275065-18542-1-git-send-email-lucas.de.marchi@gmail.com> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 54 +++++++++++++-------------- kernel/sched.c | 47 +++++------------------ kernel/sched_debug.c | 101 +++++++++++++++++++------------------------------- kernel/sched_fair.c | 65 ++++++++++++++++---------------- kernel/sched_rt.c | 2 +- 5 files changed, 106 insertions(+), 163 deletions(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 4b1753f7e48..8cc863d6647 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1127,36 +1127,8 @@ struct load_weight { unsigned long weight, inv_weight; }; -/* - * CFS stats for a schedulable entity (task, task-group etc) - * - * Current field usage histogram: - * - * 4 se->block_start - * 4 se->run_node - * 4 se->sleep_start - * 6 se->load.weight - */ -struct sched_entity { - struct load_weight load; /* for load-balancing */ - struct rb_node run_node; - struct list_head group_node; - unsigned int on_rq; - - u64 exec_start; - u64 sum_exec_runtime; - u64 vruntime; - u64 prev_sum_exec_runtime; - - u64 last_wakeup; - u64 avg_overlap; - - u64 nr_migrations; - - u64 start_runtime; - u64 avg_wakeup; - #ifdef CONFIG_SCHEDSTATS +struct sched_statistics { u64 wait_start; u64 wait_max; u64 wait_count; @@ -1188,6 +1160,30 @@ struct sched_entity { u64 nr_wakeups_affine_attempts; u64 nr_wakeups_passive; u64 nr_wakeups_idle; +}; +#endif + +struct sched_entity { + struct load_weight load; /* for load-balancing */ + struct rb_node run_node; + struct list_head group_node; + unsigned int on_rq; + + u64 exec_start; + u64 sum_exec_runtime; + u64 vruntime; + u64 prev_sum_exec_runtime; + + u64 last_wakeup; + u64 avg_overlap; + + u64 nr_migrations; + + u64 start_runtime; + u64 avg_wakeup; + +#ifdef CONFIG_SCHEDSTATS + struct sched_statistics statistics; #endif #ifdef CONFIG_FAIR_GROUP_SCHED diff --git a/kernel/sched.c b/kernel/sched.c index 2c1db81f80e..a4aa071f08f 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2437,15 +2437,15 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, out_activate: #endif /* CONFIG_SMP */ - schedstat_inc(p, se.nr_wakeups); + schedstat_inc(p, se.statistics.nr_wakeups); if (wake_flags & WF_SYNC) - schedstat_inc(p, se.nr_wakeups_sync); + schedstat_inc(p, se.statistics.nr_wakeups_sync); if (orig_cpu != cpu) - schedstat_inc(p, se.nr_wakeups_migrate); + schedstat_inc(p, se.statistics.nr_wakeups_migrate); if (cpu == this_cpu) - schedstat_inc(p, se.nr_wakeups_local); + schedstat_inc(p, se.statistics.nr_wakeups_local); else - schedstat_inc(p, se.nr_wakeups_remote); + schedstat_inc(p, se.statistics.nr_wakeups_remote); activate_task(rq, p, 1); success = 1; @@ -2532,36 +2532,7 @@ static void __sched_fork(struct task_struct *p) p->se.avg_wakeup = sysctl_sched_wakeup_granularity; #ifdef CONFIG_SCHEDSTATS - p->se.wait_start = 0; - p->se.wait_max = 0; - p->se.wait_count = 0; - p->se.wait_sum = 0; - - p->se.sleep_start = 0; - p->se.sleep_max = 0; - p->se.sum_sleep_runtime = 0; - - p->se.block_start = 0; - p->se.block_max = 0; - p->se.exec_max = 0; - p->se.slice_max = 0; - - p->se.nr_migrations_cold = 0; - p->se.nr_failed_migrations_affine = 0; - p->se.nr_failed_migrations_running = 0; - p->se.nr_failed_migrations_hot = 0; - p->se.nr_forced_migrations = 0; - - p->se.nr_wakeups = 0; - p->se.nr_wakeups_sync = 0; - p->se.nr_wakeups_migrate = 0; - p->se.nr_wakeups_local = 0; - p->se.nr_wakeups_remote = 0; - p->se.nr_wakeups_affine = 0; - p->se.nr_wakeups_affine_attempts = 0; - p->se.nr_wakeups_passive = 0; - p->se.nr_wakeups_idle = 0; - + memset(&p->se.statistics, 0, sizeof(p->se.statistics)); #endif INIT_LIST_HEAD(&p->rt.run_list); @@ -7910,9 +7881,9 @@ void normalize_rt_tasks(void) p->se.exec_start = 0; #ifdef CONFIG_SCHEDSTATS - p->se.wait_start = 0; - p->se.sleep_start = 0; - p->se.block_start = 0; + p->se.statistics.wait_start = 0; + p->se.statistics.sleep_start = 0; + p->se.statistics.block_start = 0; #endif if (!rt_task(p)) { diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 67f95aada4b..ad9df442276 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -70,16 +70,16 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, PN(se->vruntime); PN(se->sum_exec_runtime); #ifdef CONFIG_SCHEDSTATS - PN(se->wait_start); - PN(se->sleep_start); - PN(se->block_start); - PN(se->sleep_max); - PN(se->block_max); - PN(se->exec_max); - PN(se->slice_max); - PN(se->wait_max); - PN(se->wait_sum); - P(se->wait_count); + PN(se->statistics.wait_start); + PN(se->statistics.sleep_start); + PN(se->statistics.block_start); + PN(se->statistics.sleep_max); + PN(se->statistics.block_max); + PN(se->statistics.exec_max); + PN(se->statistics.slice_max); + PN(se->statistics.wait_max); + PN(se->statistics.wait_sum); + P(se->statistics.wait_count); #endif P(se->load.weight); #undef PN @@ -104,7 +104,7 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p) SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld", SPLIT_NS(p->se.vruntime), SPLIT_NS(p->se.sum_exec_runtime), - SPLIT_NS(p->se.sum_sleep_runtime)); + SPLIT_NS(p->se.statistics.sum_sleep_runtime)); #else SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld", 0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L); @@ -413,34 +413,34 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) nr_switches = p->nvcsw + p->nivcsw; #ifdef CONFIG_SCHEDSTATS - PN(se.wait_start); - PN(se.sleep_start); - PN(se.block_start); - PN(se.sleep_max); - PN(se.block_max); - PN(se.exec_max); - PN(se.slice_max); - PN(se.wait_max); - PN(se.wait_sum); - P(se.wait_count); - PN(se.iowait_sum); - P(se.iowait_count); + PN(se.statistics.wait_start); + PN(se.statistics.sleep_start); + PN(se.statistics.block_start); + PN(se.statistics.sleep_max); + PN(se.statistics.block_max); + PN(se.statistics.exec_max); + PN(se.statistics.slice_max); + PN(se.statistics.wait_max); + PN(se.statistics.wait_sum); + P(se.statistics.wait_count); + PN(se.statistics.iowait_sum); + P(se.statistics.iowait_count); P(sched_info.bkl_count); P(se.nr_migrations); - P(se.nr_migrations_cold); - P(se.nr_failed_migrations_affine); - P(se.nr_failed_migrations_running); - P(se.nr_failed_migrations_hot); - P(se.nr_forced_migrations); - P(se.nr_wakeups); - P(se.nr_wakeups_sync); - P(se.nr_wakeups_migrate); - P(se.nr_wakeups_local); - P(se.nr_wakeups_remote); - P(se.nr_wakeups_affine); - P(se.nr_wakeups_affine_attempts); - P(se.nr_wakeups_passive); - P(se.nr_wakeups_idle); + P(se.statistics.nr_migrations_cold); + P(se.statistics.nr_failed_migrations_affine); + P(se.statistics.nr_failed_migrations_running); + P(se.statistics.nr_failed_migrations_hot); + P(se.statistics.nr_forced_migrations); + P(se.statistics.nr_wakeups); + P(se.statistics.nr_wakeups_sync); + P(se.statistics.nr_wakeups_migrate); + P(se.statistics.nr_wakeups_local); + P(se.statistics.nr_wakeups_remote); + P(se.statistics.nr_wakeups_affine); + P(se.statistics.nr_wakeups_affine_attempts); + P(se.statistics.nr_wakeups_passive); + P(se.statistics.nr_wakeups_idle); { u64 avg_atom, avg_per_cpu; @@ -491,32 +491,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) void proc_sched_set_task(struct task_struct *p) { #ifdef CONFIG_SCHEDSTATS - p->se.wait_max = 0; - p->se.wait_sum = 0; - p->se.wait_count = 0; - p->se.iowait_sum = 0; - p->se.iowait_count = 0; - p->se.sleep_max = 0; - p->se.sum_sleep_runtime = 0; - p->se.block_max = 0; - p->se.exec_max = 0; - p->se.slice_max = 0; - p->se.nr_migrations = 0; - p->se.nr_migrations_cold = 0; - p->se.nr_failed_migrations_affine = 0; - p->se.nr_failed_migrations_running = 0; - p->se.nr_failed_migrations_hot = 0; - p->se.nr_forced_migrations = 0; - p->se.nr_wakeups = 0; - p->se.nr_wakeups_sync = 0; - p->se.nr_wakeups_migrate = 0; - p->se.nr_wakeups_local = 0; - p->se.nr_wakeups_remote = 0; - p->se.nr_wakeups_affine = 0; - p->se.nr_wakeups_affine_attempts = 0; - p->se.nr_wakeups_passive = 0; - p->se.nr_wakeups_idle = 0; - p->sched_info.bkl_count = 0; + memset(&p->se.statistics, 0, sizeof(p->se.statistics)); #endif p->se.sum_exec_runtime = 0; p->se.prev_sum_exec_runtime = 0; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 3e1fd96c6cf..8ad164bbdac 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -505,7 +505,8 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr, { unsigned long delta_exec_weighted; - schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max)); + schedstat_set(curr->statistics.exec_max, + max((u64)delta_exec, curr->statistics.exec_max)); curr->sum_exec_runtime += delta_exec; schedstat_add(cfs_rq, exec_clock, delta_exec); @@ -548,7 +549,7 @@ static void update_curr(struct cfs_rq *cfs_rq) static inline void update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se) { - schedstat_set(se->wait_start, rq_of(cfs_rq)->clock); + schedstat_set(se->statistics.wait_start, rq_of(cfs_rq)->clock); } /* @@ -567,18 +568,18 @@ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) static void update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) { - schedstat_set(se->wait_max, max(se->wait_max, - rq_of(cfs_rq)->clock - se->wait_start)); - schedstat_set(se->wait_count, se->wait_count + 1); - schedstat_set(se->wait_sum, se->wait_sum + - rq_of(cfs_rq)->clock - se->wait_start); + schedstat_set(se->statistics.wait_max, max(se->statistics.wait_max, + rq_of(cfs_rq)->clock - se->statistics.wait_start)); + schedstat_set(se->statistics.wait_count, se->statistics.wait_count + 1); + schedstat_set(se->statistics.wait_sum, se->statistics.wait_sum + + rq_of(cfs_rq)->clock - se->statistics.wait_start); #ifdef CONFIG_SCHEDSTATS if (entity_is_task(se)) { trace_sched_stat_wait(task_of(se), - rq_of(cfs_rq)->clock - se->wait_start); + rq_of(cfs_rq)->clock - se->statistics.wait_start); } #endif - schedstat_set(se->wait_start, 0); + schedstat_set(se->statistics.wait_start, 0); } static inline void @@ -657,39 +658,39 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) if (entity_is_task(se)) tsk = task_of(se); - if (se->sleep_start) { - u64 delta = rq_of(cfs_rq)->clock - se->sleep_start; + if (se->statistics.sleep_start) { + u64 delta = rq_of(cfs_rq)->clock - se->statistics.sleep_start; if ((s64)delta < 0) delta = 0; - if (unlikely(delta > se->sleep_max)) - se->sleep_max = delta; + if (unlikely(delta > se->statistics.sleep_max)) + se->statistics.sleep_max = delta; - se->sleep_start = 0; - se->sum_sleep_runtime += delta; + se->statistics.sleep_start = 0; + se->statistics.sum_sleep_runtime += delta; if (tsk) { account_scheduler_latency(tsk, delta >> 10, 1); trace_sched_stat_sleep(tsk, delta); } } - if (se->block_start) { - u64 delta = rq_of(cfs_rq)->clock - se->block_start; + if (se->statistics.block_start) { + u64 delta = rq_of(cfs_rq)->clock - se->statistics.block_start; if ((s64)delta < 0) delta = 0; - if (unlikely(delta > se->block_max)) - se->block_max = delta; + if (unlikely(delta > se->statistics.block_max)) + se->statistics.block_max = delta; - se->block_start = 0; - se->sum_sleep_runtime += delta; + se->statistics.block_start = 0; + se->statistics.sum_sleep_runtime += delta; if (tsk) { if (tsk->in_iowait) { - se->iowait_sum += delta; - se->iowait_count++; + se->statistics.iowait_sum += delta; + se->statistics.iowait_count++; trace_sched_stat_iowait(tsk, delta); } @@ -826,9 +827,9 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) struct task_struct *tsk = task_of(se); if (tsk->state & TASK_INTERRUPTIBLE) - se->sleep_start = rq_of(cfs_rq)->clock; + se->statistics.sleep_start = rq_of(cfs_rq)->clock; if (tsk->state & TASK_UNINTERRUPTIBLE) - se->block_start = rq_of(cfs_rq)->clock; + se->statistics.block_start = rq_of(cfs_rq)->clock; } #endif } @@ -912,7 +913,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) * when there are only lesser-weight tasks around): */ if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) { - se->slice_max = max(se->slice_max, + se->statistics.slice_max = max(se->statistics.slice_max, se->sum_exec_runtime - se->prev_sum_exec_runtime); } #endif @@ -1306,7 +1307,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) if (sync && balanced) return 1; - schedstat_inc(p, se.nr_wakeups_affine_attempts); + schedstat_inc(p, se.statistics.nr_wakeups_affine_attempts); tl_per_task = cpu_avg_load_per_task(this_cpu); if (balanced || @@ -1318,7 +1319,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) * there is no bad imbalance. */ schedstat_inc(sd, ttwu_move_affine); - schedstat_inc(p, se.nr_wakeups_affine); + schedstat_inc(p, se.statistics.nr_wakeups_affine); return 1; } @@ -1844,13 +1845,13 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, * 3) are cache-hot on their current CPU. */ if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) { - schedstat_inc(p, se.nr_failed_migrations_affine); + schedstat_inc(p, se.statistics.nr_failed_migrations_affine); return 0; } *all_pinned = 0; if (task_running(rq, p)) { - schedstat_inc(p, se.nr_failed_migrations_running); + schedstat_inc(p, se.statistics.nr_failed_migrations_running); return 0; } @@ -1866,14 +1867,14 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, #ifdef CONFIG_SCHEDSTATS if (tsk_cache_hot) { schedstat_inc(sd, lb_hot_gained[idle]); - schedstat_inc(p, se.nr_forced_migrations); + schedstat_inc(p, se.statistics.nr_forced_migrations); } #endif return 1; } if (tsk_cache_hot) { - schedstat_inc(p, se.nr_failed_migrations_hot); + schedstat_inc(p, se.statistics.nr_failed_migrations_hot); return 0; } return 1; diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index c4fb42a66ca..0335e87f520 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -613,7 +613,7 @@ static void update_curr_rt(struct rq *rq) if (unlikely((s64)delta_exec < 0)) delta_exec = 0; - schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec)); + schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec)); curr->se.sum_exec_runtime += delta_exec; account_group_exec_runtime(curr, delta_exec); -- cgit v1.2.3-70-g09d2 From 39c0cbe2150cbd848a25ba6cdb271d1ad46818ad Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Thu, 11 Mar 2010 17:17:13 +0100 Subject: sched: Rate-limit nohz Entering nohz code on every micro-idle is costing ~10% throughput for netperf TCP_RR when scheduling cross-cpu. Rate limiting entry fixes this, but raises ticks a bit. On my Q6600, an idle box goes from ~85 interrupts/sec to 128. The higher the context switch rate, the more nohz entry costs. With this patch and some cycle recovery patches in my tree, max cross cpu context switch rate is improved by ~16%, a large portion of which of which is this ratelimiting. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: <1268301003.6785.28.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 6 ++++++ kernel/sched.c | 12 ++++++++++++ kernel/time/tick-sched.c | 3 +++ 3 files changed, 21 insertions(+) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 8cc863d6647..13efe7dac5f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -271,11 +271,17 @@ extern cpumask_var_t nohz_cpu_mask; #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ) extern int select_nohz_load_balancer(int cpu); extern int get_nohz_load_balancer(void); +extern int nohz_ratelimit(int cpu); #else static inline int select_nohz_load_balancer(int cpu) { return 0; } + +static inline int nohz_ratelimit(int cpu) +{ + return 0; +} #endif /* diff --git a/kernel/sched.c b/kernel/sched.c index a4aa071f08f..60b1bbe2ad1 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -492,6 +492,7 @@ struct rq { #define CPU_LOAD_IDX_MAX 5 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; #ifdef CONFIG_NO_HZ + u64 nohz_stamp; unsigned char in_nohz_recently; #endif /* capture load from *all* tasks on this cpu: */ @@ -1228,6 +1229,17 @@ void wake_up_idle_cpu(int cpu) if (!tsk_is_polling(rq->idle)) smp_send_reschedule(cpu); } + +int nohz_ratelimit(int cpu) +{ + struct rq *rq = cpu_rq(cpu); + u64 diff = rq->clock - rq->nohz_stamp; + + rq->nohz_stamp = rq->clock; + + return diff < (NSEC_PER_SEC / HZ) >> 1; +} + #endif /* CONFIG_NO_HZ */ static u64 sched_avg_period(void) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index f992762d7f5..f25735a767a 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -262,6 +262,9 @@ void tick_nohz_stop_sched_tick(int inidle) goto end; } + if (nohz_ratelimit(cpu)) + goto end; + ts->idle_calls++; /* Read jiffies and the time when jiffies were updated last */ do { -- cgit v1.2.3-70-g09d2 From b42e0c41a422a212ddea0666d5a3a0e3c35206db Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Thu, 11 Mar 2010 17:15:38 +0100 Subject: sched: Remove avg_wakeup Testing the load which led to this heuristic (nfs4 kbuild) shows that it has outlived it's usefullness. With intervening load balancing changes, I cannot see any difference with/without, so recover there fastpath cycles. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: <1268301062.6785.29.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 3 --- kernel/sched.c | 26 ++++---------------------- kernel/sched_debug.c | 1 - kernel/sched_fair.c | 31 ------------------------------- kernel/sched_features.h | 6 ------ 5 files changed, 4 insertions(+), 63 deletions(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 13efe7dac5f..70c560f5ada 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1185,9 +1185,6 @@ struct sched_entity { u64 nr_migrations; - u64 start_runtime; - u64 avg_wakeup; - #ifdef CONFIG_SCHEDSTATS struct sched_statistics statistics; #endif diff --git a/kernel/sched.c b/kernel/sched.c index 60b1bbe2ad1..35a8626ace7 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1880,9 +1880,6 @@ static void update_avg(u64 *avg, u64 sample) static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head) { - if (wakeup) - p->se.start_runtime = p->se.sum_exec_runtime; - sched_info_queued(p); p->sched_class->enqueue_task(rq, p, wakeup, head); p->se.on_rq = 1; @@ -1890,17 +1887,11 @@ enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head) static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) { - if (sleep) { - if (p->se.last_wakeup) { - update_avg(&p->se.avg_overlap, - p->se.sum_exec_runtime - p->se.last_wakeup); - p->se.last_wakeup = 0; - } else { - update_avg(&p->se.avg_wakeup, - sysctl_sched_wakeup_granularity); - } + if (sleep && p->se.last_wakeup) { + update_avg(&p->se.avg_overlap, + p->se.sum_exec_runtime - p->se.last_wakeup); + p->se.last_wakeup = 0; } - sched_info_dequeued(p); p->sched_class->dequeue_task(rq, p, sleep); p->se.on_rq = 0; @@ -2466,13 +2457,6 @@ out_activate: */ if (!in_interrupt()) { struct sched_entity *se = ¤t->se; - u64 sample = se->sum_exec_runtime; - - if (se->last_wakeup) - sample -= se->last_wakeup; - else - sample -= se->start_runtime; - update_avg(&se->avg_wakeup, sample); se->last_wakeup = se->sum_exec_runtime; } @@ -2540,8 +2524,6 @@ static void __sched_fork(struct task_struct *p) p->se.nr_migrations = 0; p->se.last_wakeup = 0; p->se.avg_overlap = 0; - p->se.start_runtime = 0; - p->se.avg_wakeup = sysctl_sched_wakeup_granularity; #ifdef CONFIG_SCHEDSTATS memset(&p->se.statistics, 0, sizeof(p->se.statistics)); diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index ad9df442276..20b95a420fe 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -408,7 +408,6 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) PN(se.vruntime); PN(se.sum_exec_runtime); PN(se.avg_overlap); - PN(se.avg_wakeup); nr_switches = p->nvcsw + p->nivcsw; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 8ad164bbdac..6fc62854422 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1592,42 +1592,11 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag } #endif /* CONFIG_SMP */ -/* - * Adaptive granularity - * - * se->avg_wakeup gives the average time a task runs until it does a wakeup, - * with the limit of wakeup_gran -- when it never does a wakeup. - * - * So the smaller avg_wakeup is the faster we want this task to preempt, - * but we don't want to treat the preemptee unfairly and therefore allow it - * to run for at least the amount of time we'd like to run. - * - * NOTE: we use 2*avg_wakeup to increase the probability of actually doing one - * - * NOTE: we use *nr_running to scale with load, this nicely matches the - * degrading latency on load. - */ -static unsigned long -adaptive_gran(struct sched_entity *curr, struct sched_entity *se) -{ - u64 this_run = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; - u64 expected_wakeup = 2*se->avg_wakeup * cfs_rq_of(se)->nr_running; - u64 gran = 0; - - if (this_run < expected_wakeup) - gran = expected_wakeup - this_run; - - return min_t(s64, gran, sysctl_sched_wakeup_granularity); -} - static unsigned long wakeup_gran(struct sched_entity *curr, struct sched_entity *se) { unsigned long gran = sysctl_sched_wakeup_granularity; - if (cfs_rq_of(curr)->curr && sched_feat(ADAPTIVE_GRAN)) - gran = adaptive_gran(curr, se); - /* * Since its curr running now, convert the gran from real-time * to virtual-time in his units. diff --git a/kernel/sched_features.h b/kernel/sched_features.h index d5059fd761d..96ef5dbc66e 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -30,12 +30,6 @@ SCHED_FEAT(START_DEBIT, 1) */ SCHED_FEAT(WAKEUP_PREEMPT, 1) -/* - * Compute wakeup_gran based on task behaviour, clipped to - * [0, sched_wakeup_gran_ns] - */ -SCHED_FEAT(ADAPTIVE_GRAN, 1) - /* * When converting the wakeup granularity to virtual time, do it such * that heavier tasks preempting a lighter task have an edge. -- cgit v1.2.3-70-g09d2 From e12f31d3e5d36328c7fbd0fce40a95e70b59152c Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Thu, 11 Mar 2010 17:15:51 +0100 Subject: sched: Remove avg_overlap Both avg_overlap and avg_wakeup had an inherent problem in that their accuracy was detrimentally affected by cross-cpu wakeups, this because we are missing the necessary call to update_curr(). This can't be fixed without increasing overhead in our already too fat fastpath. Additionally, with recent load balancing changes making us prefer to place tasks in an idle cache domain (which is good for compute bound loads), communicating tasks suffer when a sync wakeup, which would enable affine placement, is turned into a non-sync wakeup by SYNC_LESS. With one task on the runqueue, wake_affine() rejects the affine wakeup request, leaving the unfortunate where placed, taking frequent cache misses. Remove it, and recover some fastpath cycles. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: <1268301121.6785.30.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 3 --- kernel/sched.c | 33 --------------------------------- kernel/sched_debug.c | 1 - kernel/sched_fair.c | 18 ------------------ kernel/sched_features.h | 16 ---------------- 5 files changed, 71 deletions(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 70c560f5ada..8604884cee8 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1180,9 +1180,6 @@ struct sched_entity { u64 vruntime; u64 prev_sum_exec_runtime; - u64 last_wakeup; - u64 avg_overlap; - u64 nr_migrations; #ifdef CONFIG_SCHEDSTATS diff --git a/kernel/sched.c b/kernel/sched.c index 35a8626ace7..68ed6f4f3c1 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1887,11 +1887,6 @@ enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head) static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) { - if (sleep && p->se.last_wakeup) { - update_avg(&p->se.avg_overlap, - p->se.sum_exec_runtime - p->se.last_wakeup); - p->se.last_wakeup = 0; - } sched_info_dequeued(p); p->sched_class->dequeue_task(rq, p, sleep); p->se.on_rq = 0; @@ -2452,15 +2447,6 @@ out_activate: activate_task(rq, p, 1); success = 1; - /* - * Only attribute actual wakeups done by this task. - */ - if (!in_interrupt()) { - struct sched_entity *se = ¤t->se; - - se->last_wakeup = se->sum_exec_runtime; - } - out_running: trace_sched_wakeup(rq, p, success); check_preempt_curr(rq, p, wake_flags); @@ -2522,8 +2508,6 @@ static void __sched_fork(struct task_struct *p) p->se.sum_exec_runtime = 0; p->se.prev_sum_exec_runtime = 0; p->se.nr_migrations = 0; - p->se.last_wakeup = 0; - p->se.avg_overlap = 0; #ifdef CONFIG_SCHEDSTATS memset(&p->se.statistics, 0, sizeof(p->se.statistics)); @@ -3594,23 +3578,6 @@ static inline void schedule_debug(struct task_struct *prev) static void put_prev_task(struct rq *rq, struct task_struct *prev) { - if (prev->state == TASK_RUNNING) { - u64 runtime = prev->se.sum_exec_runtime; - - runtime -= prev->se.prev_sum_exec_runtime; - runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); - - /* - * In order to avoid avg_overlap growing stale when we are - * indeed overlapping and hence not getting put to sleep, grow - * the avg_overlap on preemption. - * - * We use the average preemption runtime because that - * correlates to the amount of cache footprint a task can - * build up. - */ - update_avg(&prev->se.avg_overlap, runtime); - } prev->sched_class->put_prev_task(rq, prev); } diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 20b95a420fe..8a46a719f36 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -407,7 +407,6 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) PN(se.exec_start); PN(se.vruntime); PN(se.sum_exec_runtime); - PN(se.avg_overlap); nr_switches = p->nvcsw + p->nivcsw; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 6fc62854422..c3b69d4b5d6 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1241,7 +1241,6 @@ static inline unsigned long effective_load(struct task_group *tg, int cpu, static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) { - struct task_struct *curr = current; unsigned long this_load, load; int idx, this_cpu, prev_cpu; unsigned long tl_per_task; @@ -1256,18 +1255,6 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) load = source_load(prev_cpu, idx); this_load = target_load(this_cpu, idx); - if (sync) { - if (sched_feat(SYNC_LESS) && - (curr->se.avg_overlap > sysctl_sched_migration_cost || - p->se.avg_overlap > sysctl_sched_migration_cost)) - sync = 0; - } else { - if (sched_feat(SYNC_MORE) && - (curr->se.avg_overlap < sysctl_sched_migration_cost && - p->se.avg_overlap < sysctl_sched_migration_cost)) - sync = 1; - } - /* * If sync wakeup then subtract the (maximum possible) * effect of the currently running task from the load @@ -1711,11 +1698,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ if (sched_feat(WAKEUP_SYNC) && sync) goto preempt; - if (sched_feat(WAKEUP_OVERLAP) && - se->avg_overlap < sysctl_sched_migration_cost && - pse->avg_overlap < sysctl_sched_migration_cost) - goto preempt; - if (!sched_feat(WAKEUP_PREEMPT)) return; diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 96ef5dbc66e..c545e048dfe 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -41,12 +41,6 @@ SCHED_FEAT(ASYM_GRAN, 1) */ SCHED_FEAT(WAKEUP_SYNC, 0) -/* - * Wakeup preempt based on task behaviour. Tasks that do not overlap - * don't get preempted. - */ -SCHED_FEAT(WAKEUP_OVERLAP, 0) - /* * Use the SYNC wakeup hint, pipes and the likes use this to indicate * the remote end is likely to consume the data we just wrote, and @@ -63,16 +57,6 @@ SCHED_FEAT(SYNC_WAKEUPS, 1) */ SCHED_FEAT(AFFINE_WAKEUPS, 1) -/* - * Weaken SYNC hint based on overlap - */ -SCHED_FEAT(SYNC_LESS, 1) - -/* - * Add SYNC hint based on overlap - */ -SCHED_FEAT(SYNC_MORE, 0) - /* * Prefer to schedule the task we woke last (assuming it failed * wakeup-preemption), since its likely going to consume data we -- cgit v1.2.3-70-g09d2 From faa4602e47690fb11221e00f9b9697c8dc0d4b19 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 25 Mar 2010 14:51:50 +0100 Subject: x86, perf, bts, mm: Delete the never used BTS-ptrace code Support for the PMU's BTS features has been upstreamed in v2.6.32, but we still have the old and disabled ptrace-BTS, as Linus noticed it not so long ago. It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without regard for other uses (perf) and doesn't provide the flexibility needed for perf either. Its users are ptrace-block-step and ptrace-bts, since ptrace-bts was never used and ptrace-block-step can be implemented using a much simpler approach. So axe all 3000 lines of it. That includes the *locked_memory*() APIs in mm/mlock.c as well. Reported-by: Linus Torvalds Signed-off-by: Peter Zijlstra Cc: Roland McGrath Cc: Oleg Nesterov Cc: Markus Metzger Cc: Steven Rostedt Cc: Andrew Morton LKML-Reference: <20100325135413.938004390@chello.nl> Signed-off-by: Ingo Molnar --- arch/x86/Kconfig.cpu | 20 - arch/x86/Kconfig.debug | 9 - arch/x86/include/asm/ds.h | 302 -------- arch/x86/include/asm/processor.h | 33 +- arch/x86/include/asm/ptrace-abi.h | 57 +- arch/x86/include/asm/ptrace.h | 6 - arch/x86/include/asm/thread_info.h | 6 +- arch/x86/kernel/Makefile | 2 - arch/x86/kernel/cpu/intel.c | 2 - arch/x86/kernel/ds.c | 1437 ------------------------------------ arch/x86/kernel/ds_selftest.c | 408 ---------- arch/x86/kernel/ds_selftest.h | 15 - arch/x86/kernel/dumpstack.c | 5 - arch/x86/kernel/kprobes.c | 6 +- arch/x86/kernel/process.c | 9 - arch/x86/kernel/process_32.c | 8 - arch/x86/kernel/process_64.c | 8 - arch/x86/kernel/ptrace.c | 382 ---------- arch/x86/kernel/step.c | 36 +- arch/x86/kernel/traps.c | 5 - include/linux/ftrace.h | 12 - include/linux/mm.h | 4 - include/linux/ptrace.h | 12 - include/linux/sched.h | 9 - kernel/fork.c | 3 - kernel/ptrace.c | 1 - kernel/sched.c | 43 -- kernel/trace/Kconfig | 11 - kernel/trace/Makefile | 1 - kernel/trace/trace.h | 4 - kernel/trace/trace_entries.h | 12 - kernel/trace/trace_hw_branches.c | 312 -------- kernel/trace/trace_selftest.c | 57 -- mm/mlock.c | 41 - 34 files changed, 9 insertions(+), 3269 deletions(-) delete mode 100644 arch/x86/include/asm/ds.h delete mode 100644 arch/x86/kernel/ds.c delete mode 100644 arch/x86/kernel/ds_selftest.c delete mode 100644 arch/x86/kernel/ds_selftest.h delete mode 100644 kernel/trace/trace_hw_branches.c (limited to 'include') diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index a19829374e6..918fbb1855c 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -502,23 +502,3 @@ config CPU_SUP_UMC_32 CPU might render the kernel unbootable. If unsure, say N. - -config X86_DS - def_bool X86_PTRACE_BTS - depends on X86_DEBUGCTLMSR - select HAVE_HW_BRANCH_TRACER - -config X86_PTRACE_BTS - bool "Branch Trace Store" - default y - depends on X86_DEBUGCTLMSR - depends on BROKEN - ---help--- - This adds a ptrace interface to the hardware's branch trace store. - - Debuggers may use it to collect an execution trace of the debugged - application in order to answer the question 'how did I get here?'. - Debuggers may trace user mode as well as kernel mode. - - Say Y unless there is no application development on this machine - and you want to save a small amount of code size. diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index bc01e3ebfeb..bd58c8abbfb 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -174,15 +174,6 @@ config IOMMU_LEAK Add a simple leak tracer to the IOMMU code. This is useful when you are debugging a buggy device driver that leaks IOMMU mappings. -config X86_DS_SELFTEST - bool "DS selftest" - default y - depends on DEBUG_KERNEL - depends on X86_DS - ---help--- - Perform Debug Store selftests at boot time. - If in doubt, say "N". - config HAVE_MMIOTRACE_SUPPORT def_bool y diff --git a/arch/x86/include/asm/ds.h b/arch/x86/include/asm/ds.h deleted file mode 100644 index 70dac199b09..00000000000 --- a/arch/x86/include/asm/ds.h +++ /dev/null @@ -1,302 +0,0 @@ -/* - * Debug Store (DS) support - * - * This provides a low-level interface to the hardware's Debug Store - * feature that is used for branch trace store (BTS) and - * precise-event based sampling (PEBS). - * - * It manages: - * - DS and BTS hardware configuration - * - buffer overflow handling (to be done) - * - buffer access - * - * It does not do: - * - security checking (is the caller allowed to trace the task) - * - buffer allocation (memory accounting) - * - * - * Copyright (C) 2007-2009 Intel Corporation. - * Markus Metzger , 2007-2009 - */ - -#ifndef _ASM_X86_DS_H -#define _ASM_X86_DS_H - - -#include -#include -#include - - -#ifdef CONFIG_X86_DS - -struct task_struct; -struct ds_context; -struct ds_tracer; -struct bts_tracer; -struct pebs_tracer; - -typedef void (*bts_ovfl_callback_t)(struct bts_tracer *); -typedef void (*pebs_ovfl_callback_t)(struct pebs_tracer *); - - -/* - * A list of features plus corresponding macros to talk about them in - * the ds_request function's flags parameter. - * - * We use the enum to index an array of corresponding control bits; - * we use the macro to index a flags bit-vector. - */ -enum ds_feature { - dsf_bts = 0, - dsf_bts_kernel, -#define BTS_KERNEL (1 << dsf_bts_kernel) - /* trace kernel-mode branches */ - - dsf_bts_user, -#define BTS_USER (1 << dsf_bts_user) - /* trace user-mode branches */ - - dsf_bts_overflow, - dsf_bts_max, - dsf_pebs = dsf_bts_max, - - dsf_pebs_max, - dsf_ctl_max = dsf_pebs_max, - dsf_bts_timestamps = dsf_ctl_max, -#define BTS_TIMESTAMPS (1 << dsf_bts_timestamps) - /* add timestamps into BTS trace */ - -#define BTS_USER_FLAGS (BTS_KERNEL | BTS_USER | BTS_TIMESTAMPS) -}; - - -/* - * Request BTS or PEBS - * - * Due to alignement constraints, the actual buffer may be slightly - * smaller than the requested or provided buffer. - * - * Returns a pointer to a tracer structure on success, or - * ERR_PTR(errcode) on failure. - * - * The interrupt threshold is independent from the overflow callback - * to allow users to use their own overflow interrupt handling mechanism. - * - * The function might sleep. - * - * task: the task to request recording for - * cpu: the cpu to request recording for - * base: the base pointer for the (non-pageable) buffer; - * size: the size of the provided buffer in bytes - * ovfl: pointer to a function to be called on buffer overflow; - * NULL if cyclic buffer requested - * th: the interrupt threshold in records from the end of the buffer; - * -1 if no interrupt threshold is requested. - * flags: a bit-mask of the above flags - */ -extern struct bts_tracer *ds_request_bts_task(struct task_struct *task, - void *base, size_t size, - bts_ovfl_callback_t ovfl, - size_t th, unsigned int flags); -extern struct bts_tracer *ds_request_bts_cpu(int cpu, void *base, size_t size, - bts_ovfl_callback_t ovfl, - size_t th, unsigned int flags); -extern struct pebs_tracer *ds_request_pebs_task(struct task_struct *task, - void *base, size_t size, - pebs_ovfl_callback_t ovfl, - size_t th, unsigned int flags); -extern struct pebs_tracer *ds_request_pebs_cpu(int cpu, - void *base, size_t size, - pebs_ovfl_callback_t ovfl, - size_t th, unsigned int flags); - -/* - * Release BTS or PEBS resources - * Suspend and resume BTS or PEBS tracing - * - * Must be called with irq's enabled. - * - * tracer: the tracer handle returned from ds_request_~() - */ -extern void ds_release_bts(struct bts_tracer *tracer); -extern void ds_suspend_bts(struct bts_tracer *tracer); -extern void ds_resume_bts(struct bts_tracer *tracer); -extern void ds_release_pebs(struct pebs_tracer *tracer); -extern void ds_suspend_pebs(struct pebs_tracer *tracer); -extern void ds_resume_pebs(struct pebs_tracer *tracer); - -/* - * Release BTS or PEBS resources - * Suspend and resume BTS or PEBS tracing - * - * Cpu tracers must call this on the traced cpu. - * Task tracers must call ds_release_~_noirq() for themselves. - * - * May be called with irq's disabled. - * - * Returns 0 if successful; - * -EPERM if the cpu tracer does not trace the current cpu. - * -EPERM if the task tracer does not trace itself. - * - * tracer: the tracer handle returned from ds_request_~() - */ -extern int ds_release_bts_noirq(struct bts_tracer *tracer); -extern int ds_suspend_bts_noirq(struct bts_tracer *tracer); -extern int ds_resume_bts_noirq(struct bts_tracer *tracer); -extern int ds_release_pebs_noirq(struct pebs_tracer *tracer); -extern int ds_suspend_pebs_noirq(struct pebs_tracer *tracer); -extern int ds_resume_pebs_noirq(struct pebs_tracer *tracer); - - -/* - * The raw DS buffer state as it is used for BTS and PEBS recording. - * - * This is the low-level, arch-dependent interface for working - * directly on the raw trace data. - */ -struct ds_trace { - /* the number of bts/pebs records */ - size_t n; - /* the size of a bts/pebs record in bytes */ - size_t size; - /* pointers into the raw buffer: - - to the first entry */ - void *begin; - /* - one beyond the last entry */ - void *end; - /* - one beyond the newest entry */ - void *top; - /* - the interrupt threshold */ - void *ith; - /* flags given on ds_request() */ - unsigned int flags; -}; - -/* - * An arch-independent view on branch trace data. - */ -enum bts_qualifier { - bts_invalid, -#define BTS_INVALID bts_invalid - - bts_branch, -#define BTS_BRANCH bts_branch - - bts_task_arrives, -#define BTS_TASK_ARRIVES bts_task_arrives - - bts_task_departs, -#define BTS_TASK_DEPARTS bts_task_departs - - bts_qual_bit_size = 4, - bts_qual_max = (1 << bts_qual_bit_size), -}; - -struct bts_struct { - __u64 qualifier; - union { - /* BTS_BRANCH */ - struct { - __u64 from; - __u64 to; - } lbr; - /* BTS_TASK_ARRIVES or BTS_TASK_DEPARTS */ - struct { - __u64 clock; - pid_t pid; - } event; - } variant; -}; - - -/* - * The BTS state. - * - * This gives access to the raw DS state and adds functions to provide - * an arch-independent view of the BTS data. - */ -struct bts_trace { - struct ds_trace ds; - - int (*read)(struct bts_tracer *tracer, const void *at, - struct bts_struct *out); - int (*write)(struct bts_tracer *tracer, const struct bts_struct *in); -}; - - -/* - * The PEBS state. - * - * This gives access to the raw DS state and the PEBS-specific counter - * reset value. - */ -struct pebs_trace { - struct ds_trace ds; - - /* the number of valid counters in the below array */ - unsigned int counters; - -#define MAX_PEBS_COUNTERS 4 - /* the counter reset value */ - unsigned long long counter_reset[MAX_PEBS_COUNTERS]; -}; - - -/* - * Read the BTS or PEBS trace. - * - * Returns a view on the trace collected for the parameter tracer. - * - * The view remains valid as long as the traced task is not running or - * the tracer is suspended. - * Writes into the trace buffer are not reflected. - * - * tracer: the tracer handle returned from ds_request_~() - */ -extern const struct bts_trace *ds_read_bts(struct bts_tracer *tracer); -extern const struct pebs_trace *ds_read_pebs(struct pebs_tracer *tracer); - - -/* - * Reset the write pointer of the BTS/PEBS buffer. - * - * Returns 0 on success; -Eerrno on error - * - * tracer: the tracer handle returned from ds_request_~() - */ -extern int ds_reset_bts(struct bts_tracer *tracer); -extern int ds_reset_pebs(struct pebs_tracer *tracer); - -/* - * Set the PEBS counter reset value. - * - * Returns 0 on success; -Eerrno on error - * - * tracer: the tracer handle returned from ds_request_pebs() - * counter: the index of the counter - * value: the new counter reset value - */ -extern int ds_set_pebs_reset(struct pebs_tracer *tracer, - unsigned int counter, u64 value); - -/* - * Initialization - */ -struct cpuinfo_x86; -extern void __cpuinit ds_init_intel(struct cpuinfo_x86 *); - -/* - * Context switch work - */ -extern void ds_switch_to(struct task_struct *prev, struct task_struct *next); - -#else /* CONFIG_X86_DS */ - -struct cpuinfo_x86; -static inline void __cpuinit ds_init_intel(struct cpuinfo_x86 *ignored) {} -static inline void ds_switch_to(struct task_struct *prev, - struct task_struct *next) {} - -#endif /* CONFIG_X86_DS */ -#endif /* _ASM_X86_DS_H */ diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index b753ea59703..5bec21a66dc 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -21,7 +21,6 @@ struct mm_struct; #include #include #include -#include #include #include @@ -29,6 +28,7 @@ struct mm_struct; #include #include #include +#include #define HBP_NUM 4 /* @@ -473,10 +473,6 @@ struct thread_struct { unsigned long iopl; /* Max allowed port in the bitmap, in bytes: */ unsigned io_bitmap_max; -/* MSR_IA32_DEBUGCTLMSR value to switch in if TIF_DEBUGCTLMSR is set. */ - unsigned long debugctlmsr; - /* Debug Store context; see asm/ds.h */ - struct ds_context *ds_ctx; }; static inline unsigned long native_get_debugreg(int regno) @@ -814,21 +810,6 @@ static inline unsigned long get_debugctlmsr(void) return debugctlmsr; } -static inline unsigned long get_debugctlmsr_on_cpu(int cpu) -{ - u64 debugctlmsr = 0; - u32 val1, val2; - -#ifndef CONFIG_X86_DEBUGCTLMSR - if (boot_cpu_data.x86 < 6) - return 0; -#endif - rdmsr_on_cpu(cpu, MSR_IA32_DEBUGCTLMSR, &val1, &val2); - debugctlmsr = val1 | ((u64)val2 << 32); - - return debugctlmsr; -} - static inline void update_debugctlmsr(unsigned long debugctlmsr) { #ifndef CONFIG_X86_DEBUGCTLMSR @@ -838,18 +819,6 @@ static inline void update_debugctlmsr(unsigned long debugctlmsr) wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr); } -static inline void update_debugctlmsr_on_cpu(int cpu, - unsigned long debugctlmsr) -{ -#ifndef CONFIG_X86_DEBUGCTLMSR - if (boot_cpu_data.x86 < 6) - return; -#endif - wrmsr_on_cpu(cpu, MSR_IA32_DEBUGCTLMSR, - (u32)((u64)debugctlmsr), - (u32)((u64)debugctlmsr >> 32)); -} - /* * from system description table in BIOS. Mostly for MCA use, but * others may find it useful: diff --git a/arch/x86/include/asm/ptrace-abi.h b/arch/x86/include/asm/ptrace-abi.h index 86723035a51..52b098a6eeb 100644 --- a/arch/x86/include/asm/ptrace-abi.h +++ b/arch/x86/include/asm/ptrace-abi.h @@ -82,61 +82,6 @@ #ifndef __ASSEMBLY__ #include - -/* configuration/status structure used in PTRACE_BTS_CONFIG and - PTRACE_BTS_STATUS commands. -*/ -struct ptrace_bts_config { - /* requested or actual size of BTS buffer in bytes */ - __u32 size; - /* bitmask of below flags */ - __u32 flags; - /* buffer overflow signal */ - __u32 signal; - /* actual size of bts_struct in bytes */ - __u32 bts_size; -}; -#endif /* __ASSEMBLY__ */ - -#define PTRACE_BTS_O_TRACE 0x1 /* branch trace */ -#define PTRACE_BTS_O_SCHED 0x2 /* scheduling events w/ jiffies */ -#define PTRACE_BTS_O_SIGNAL 0x4 /* send SIG on buffer overflow - instead of wrapping around */ -#define PTRACE_BTS_O_ALLOC 0x8 /* (re)allocate buffer */ - -#define PTRACE_BTS_CONFIG 40 -/* Configure branch trace recording. - ADDR points to a struct ptrace_bts_config. - DATA gives the size of that buffer. - A new buffer is allocated, if requested in the flags. - An overflow signal may only be requested for new buffers. - Returns the number of bytes read. -*/ -#define PTRACE_BTS_STATUS 41 -/* Return the current configuration in a struct ptrace_bts_config - pointed to by ADDR; DATA gives the size of that buffer. - Returns the number of bytes written. -*/ -#define PTRACE_BTS_SIZE 42 -/* Return the number of available BTS records for draining. - DATA and ADDR are ignored. -*/ -#define PTRACE_BTS_GET 43 -/* Get a single BTS record. - DATA defines the index into the BTS array, where 0 is the newest - entry, and higher indices refer to older entries. - ADDR is pointing to struct bts_struct (see asm/ds.h). -*/ -#define PTRACE_BTS_CLEAR 44 -/* Clear the BTS buffer. - DATA and ADDR are ignored. -*/ -#define PTRACE_BTS_DRAIN 45 -/* Read all available BTS records and clear the buffer. - ADDR points to an array of struct bts_struct. - DATA gives the size of that buffer. - BTS records are read from oldest to newest. - Returns number of BTS records drained. -*/ +#endif #endif /* _ASM_X86_PTRACE_ABI_H */ diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 69a686a7dff..78cd1ea9450 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -289,12 +289,6 @@ extern int do_get_thread_area(struct task_struct *p, int idx, extern int do_set_thread_area(struct task_struct *p, int idx, struct user_desc __user *info, int can_allocate); -#ifdef CONFIG_X86_PTRACE_BTS -extern void ptrace_bts_untrace(struct task_struct *tsk); - -#define arch_ptrace_untrace(tsk) ptrace_bts_untrace(tsk) -#endif /* CONFIG_X86_PTRACE_BTS */ - #endif /* __KERNEL__ */ #endif /* !__ASSEMBLY__ */ diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index e0d28901e96..dc85e12d140 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -92,8 +92,6 @@ struct thread_info { #define TIF_IO_BITMAP 22 /* uses I/O bitmap */ #define TIF_FREEZE 23 /* is freezing for suspend */ #define TIF_FORCED_TF 24 /* true if TF in eflags artificially */ -#define TIF_DEBUGCTLMSR 25 /* uses thread_struct.debugctlmsr */ -#define TIF_DS_AREA_MSR 26 /* uses thread_struct.ds_area_msr */ #define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */ #define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */ @@ -115,8 +113,6 @@ struct thread_info { #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP) #define _TIF_FREEZE (1 << TIF_FREEZE) #define _TIF_FORCED_TF (1 << TIF_FORCED_TF) -#define _TIF_DEBUGCTLMSR (1 << TIF_DEBUGCTLMSR) -#define _TIF_DS_AREA_MSR (1 << TIF_DS_AREA_MSR) #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES) #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) @@ -147,7 +143,7 @@ struct thread_info { /* flags to check in __switch_to() */ #define _TIF_WORK_CTXSW \ - (_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_NOTSC) + (_TIF_IO_BITMAP|_TIF_NOTSC) #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY) #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG) diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 4c58352209e..e77b2208372 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -47,8 +47,6 @@ obj-$(CONFIG_X86_TRAMPOLINE) += trampoline.o obj-y += process.o obj-y += i387.o xsave.o obj-y += ptrace.o -obj-$(CONFIG_X86_DS) += ds.o -obj-$(CONFIG_X86_DS_SELFTEST) += ds_selftest.o obj-$(CONFIG_X86_32) += tls.o obj-$(CONFIG_IA32_EMULATION) += tls.o obj-y += step.o diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 7e1cca13af3..d72377c41c7 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include @@ -367,7 +366,6 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c) set_cpu_cap(c, X86_FEATURE_BTS); if (!(l1 & (1<<12))) set_cpu_cap(c, X86_FEATURE_PEBS); - ds_init_intel(c); } if (c->x86 == 6 && c->x86_model == 29 && cpu_has_clflush) diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c deleted file mode 100644 index 1c47390dd0e..00000000000 --- a/arch/x86/kernel/ds.c +++ /dev/null @@ -1,1437 +0,0 @@ -/* - * Debug Store support - * - * This provides a low-level interface to the hardware's Debug Store - * feature that is used for branch trace store (BTS) and - * precise-event based sampling (PEBS). - * - * It manages: - * - DS and BTS hardware configuration - * - buffer overflow handling (to be done) - * - buffer access - * - * It does not do: - * - security checking (is the caller allowed to trace the task) - * - buffer allocation (memory accounting) - * - * - * Copyright (C) 2007-2009 Intel Corporation. - * Markus Metzger , 2007-2009 - */ - -#include -#include -#include -#include -#include -#include -#include - -#include - -#include "ds_selftest.h" - -/* - * The configuration for a particular DS hardware implementation: - */ -struct ds_configuration { - /* The name of the configuration: */ - const char *name; - - /* The size of pointer-typed fields in DS, BTS, and PEBS: */ - unsigned char sizeof_ptr_field; - - /* The size of a BTS/PEBS record in bytes: */ - unsigned char sizeof_rec[2]; - - /* The number of pebs counter reset values in the DS structure. */ - unsigned char nr_counter_reset; - - /* Control bit-masks indexed by enum ds_feature: */ - unsigned long ctl[dsf_ctl_max]; -}; -static struct ds_configuration ds_cfg __read_mostly; - - -/* Maximal size of a DS configuration: */ -#define MAX_SIZEOF_DS 0x80 - -/* Maximal size of a BTS record: */ -#define MAX_SIZEOF_BTS (3 * 8) - -/* BTS and PEBS buffer alignment: */ -#define DS_ALIGNMENT (1 << 3) - -/* Number of buffer pointers in DS: */ -#define NUM_DS_PTR_FIELDS 8 - -/* Size of a pebs reset value in DS: */ -#define PEBS_RESET_FIELD_SIZE 8 - -/* Mask of control bits in the DS MSR register: */ -#define BTS_CONTROL \ - ( ds_cfg.ctl[dsf_bts] | \ - ds_cfg.ctl[dsf_bts_kernel] | \ - ds_cfg.ctl[dsf_bts_user] | \ - ds_cfg.ctl[dsf_bts_overflow] ) - -/* - * A BTS or PEBS tracer. - * - * This holds the configuration of the tracer and serves as a handle - * to identify tracers. - */ -struct ds_tracer { - /* The DS context (partially) owned by this tracer. */ - struct ds_context *context; - /* The buffer provided on ds_request() and its size in bytes. */ - void *buffer; - size_t size; -}; - -struct bts_tracer { - /* The common DS part: */ - struct ds_tracer ds; - - /* The trace including the DS configuration: */ - struct bts_trace trace; - - /* Buffer overflow notification function: */ - bts_ovfl_callback_t ovfl; - - /* Active flags affecting trace collection. */ - unsigned int flags; -}; - -struct pebs_tracer { - /* The common DS part: */ - struct ds_tracer ds; - - /* The trace including the DS configuration: */ - struct pebs_trace trace; - - /* Buffer overflow notification function: */ - pebs_ovfl_callback_t ovfl; -}; - -/* - * Debug Store (DS) save area configuration (see Intel64 and IA32 - * Architectures Software Developer's Manual, section 18.5) - * - * The DS configuration consists of the following fields; different - * architetures vary in the size of those fields. - * - * - double-word aligned base linear address of the BTS buffer - * - write pointer into the BTS buffer - * - end linear address of the BTS buffer (one byte beyond the end of - * the buffer) - * - interrupt pointer into BTS buffer - * (interrupt occurs when write pointer passes interrupt pointer) - * - double-word aligned base linear address of the PEBS buffer - * - write pointer into the PEBS buffer - * - end linear address of the PEBS buffer (one byte beyond the end of - * the buffer) - * - interrupt pointer into PEBS buffer - * (interrupt occurs when write pointer passes interrupt pointer) - * - value to which counter is reset following counter overflow - * - * Later architectures use 64bit pointers throughout, whereas earlier - * architectures use 32bit pointers in 32bit mode. - * - * - * We compute the base address for the first 8 fields based on: - * - the field size stored in the DS configuration - * - the relative field position - * - an offset giving the start of the respective region - * - * This offset is further used to index various arrays holding - * information for BTS and PEBS at the respective index. - * - * On later 32bit processors, we only access the lower 32bit of the - * 64bit pointer fields. The upper halves will be zeroed out. - */ - -enum ds_field { - ds_buffer_base = 0, - ds_index, - ds_absolute_maximum, - ds_interrupt_threshold, -}; - -enum ds_qualifier { - ds_bts = 0, - ds_pebs -}; - -static inline unsigned long -ds_get(const unsigned char *base, enum ds_qualifier qual, enum ds_field field) -{ - base += (ds_cfg.sizeof_ptr_field * (field + (4 * qual))); - return *(unsigned long *)base; -} - -static inline void -ds_set(unsigned char *base, enum ds_qualifier qual, enum ds_field field, - unsigned long value) -{ - base += (ds_cfg.sizeof_ptr_field * (field + (4 * qual))); - (*(unsigned long *)base) = value; -} - - -/* - * Locking is done only for allocating BTS or PEBS resources. - */ -static DEFINE_SPINLOCK(ds_lock); - -/* - * We either support (system-wide) per-cpu or per-thread allocation. - * We distinguish the two based on the task_struct pointer, where a - * NULL pointer indicates per-cpu allocation for the current cpu. - * - * Allocations are use-counted. As soon as resources are allocated, - * further allocations must be of the same type (per-cpu or - * per-thread). We model this by counting allocations (i.e. the number - * of tracers of a certain type) for one type negatively: - * =0 no tracers - * >0 number of per-thread tracers - * <0 number of per-cpu tracers - * - * Tracers essentially gives the number of ds contexts for a certain - * type of allocation. - */ -static atomic_t tracers = ATOMIC_INIT(0); - -static inline int get_tracer(struct task_struct *task) -{ - int error; - - spin_lock_irq(&ds_lock); - - if (task) { - error = -EPERM; - if (atomic_read(&tracers) < 0) - goto out; - atomic_inc(&tracers); - } else { - error = -EPERM; - if (atomic_read(&tracers) > 0) - goto out; - atomic_dec(&tracers); - } - - error = 0; -out: - spin_unlock_irq(&ds_lock); - return error; -} - -static inline void put_tracer(struct task_struct *task) -{ - if (task) - atomic_dec(&tracers); - else - atomic_inc(&tracers); -} - -/* - * The DS context is either attached to a thread or to a cpu: - * - in the former case, the thread_struct contains a pointer to the - * attached context. - * - in the latter case, we use a static array of per-cpu context - * pointers. - * - * Contexts are use-counted. They are allocated on first access and - * deallocated when the last user puts the context. - */ -struct ds_context { - /* The DS configuration; goes into MSR_IA32_DS_AREA: */ - unsigned char ds[MAX_SIZEOF_DS]; - - /* The owner of the BTS and PEBS configuration, respectively: */ - struct bts_tracer *bts_master; - struct pebs_tracer *pebs_master; - - /* Use count: */ - unsigned long count; - - /* Pointer to the context pointer field: */ - struct ds_context **this; - - /* The traced task; NULL for cpu tracing: */ - struct task_struct *task; - - /* The traced cpu; only valid if task is NULL: */ - int cpu; -}; - -static DEFINE_PER_CPU(struct ds_context *, cpu_ds_context); - - -static struct ds_context *ds_get_context(struct task_struct *task, int cpu) -{ - struct ds_context **p_context = - (task ? &task->thread.ds_ctx : &per_cpu(cpu_ds_context, cpu)); - struct ds_context *context = NULL; - struct ds_context *new_context = NULL; - - /* Chances are small that we already have a context. */ - new_context = kzalloc(sizeof(*new_context), GFP_KERNEL); - if (!new_context) - return NULL; - - spin_lock_irq(&ds_lock); - - context = *p_context; - if (likely(!context)) { - context = new_context; - - context->this = p_context; - context->task = task; - context->cpu = cpu; - context->count = 0; - - *p_context = context; - } - - context->count++; - - spin_unlock_irq(&ds_lock); - - if (context != new_context) - kfree(new_context); - - return context; -} - -static void ds_put_context(struct ds_context *context) -{ - struct task_struct *task; - unsigned long irq; - - if (!context) - return; - - spin_lock_irqsave(&ds_lock, irq); - - if (--context->count) { - spin_unlock_irqrestore(&ds_lock, irq); - return; - } - - *(context->this) = NULL; - - task = context->task; - - if (task) - clear_tsk_thread_flag(task, TIF_DS_AREA_MSR); - - /* - * We leave the (now dangling) pointer to the DS configuration in - * the DS_AREA msr. This is as good or as bad as replacing it with - * NULL - the hardware would crash if we enabled tracing. - * - * This saves us some problems with having to write an msr on a - * different cpu while preventing others from doing the same for the - * next context for that same cpu. - */ - - spin_unlock_irqrestore(&ds_lock, irq); - - /* The context might still be in use for context switching. */ - if (task && (task != current)) - wait_task_context_switch(task); - - kfree(context); -} - -static void ds_install_ds_area(struct ds_context *context) -{ - unsigned long ds; - - ds = (unsigned long)context->ds; - - /* - * There is a race between the bts master and the pebs master. - * - * The thread/cpu access is synchronized via get/put_cpu() for - * task tracing and via wrmsr_on_cpu for cpu tracing. - * - * If bts and pebs are collected for the same task or same cpu, - * the same confiuration is written twice. - */ - if (context->task) { - get_cpu(); - if (context->task == current) - wrmsrl(MSR_IA32_DS_AREA, ds); - set_tsk_thread_flag(context->task, TIF_DS_AREA_MSR); - put_cpu(); - } else - wrmsr_on_cpu(context->cpu, MSR_IA32_DS_AREA, - (u32)((u64)ds), (u32)((u64)ds >> 32)); -} - -/* - * Call the tracer's callback on a buffer overflow. - * - * context: the ds context - * qual: the buffer type - */ -static void ds_overflow(struct ds_context *context, enum ds_qualifier qual) -{ - switch (qual) { - case ds_bts: - if (context->bts_master && - context->bts_master->ovfl) - context->bts_master->ovfl(context->bts_master); - break; - case ds_pebs: - if (context->pebs_master && - context->pebs_master->ovfl) - context->pebs_master->ovfl(context->pebs_master); - break; - } -} - - -/* - * Write raw data into the BTS or PEBS buffer. - * - * The remainder of any partially written record is zeroed out. - * - * context: the DS context - * qual: the buffer type - * record: the data to write - * size: the size of the data - */ -static int ds_write(struct ds_context *context, enum ds_qualifier qual, - const void *record, size_t size) -{ - int bytes_written = 0; - - if (!record) - return -EINVAL; - - while (size) { - unsigned long base, index, end, write_end, int_th; - unsigned long write_size, adj_write_size; - - /* - * Write as much as possible without producing an - * overflow interrupt. - * - * Interrupt_threshold must either be - * - bigger than absolute_maximum or - * - point to a record between buffer_base and absolute_maximum - * - * Index points to a valid record. - */ - base = ds_get(context->ds, qual, ds_buffer_base); - index = ds_get(context->ds, qual, ds_index); - end = ds_get(context->ds, qual, ds_absolute_maximum); - int_th = ds_get(context->ds, qual, ds_interrupt_threshold); - - write_end = min(end, int_th); - - /* - * If we are already beyond the interrupt threshold, - * we fill the entire buffer. - */ - if (write_end <= index) - write_end = end; - - if (write_end <= index) - break; - - write_size = min((unsigned long) size, write_end - index); - memcpy((void *)index, record, write_size); - - record = (const char *)record + write_size; - size -= write_size; - bytes_written += write_size; - - adj_write_size = write_size / ds_cfg.sizeof_rec[qual]; - adj_write_size *= ds_cfg.sizeof_rec[qual]; - - /* Zero out trailing bytes. */ - memset((char *)index + write_size, 0, - adj_write_size - write_size); - index += adj_write_size; - - if (index >= end) - index = base; - ds_set(context->ds, qual, ds_index, index); - - if (index >= int_th) - ds_overflow(context, qual); - } - - return bytes_written; -} - - -/* - * Branch Trace Store (BTS) uses the following format. Different - * architectures vary in the size of those fields. - * - source linear address - * - destination linear address - * - flags - * - * Later architectures use 64bit pointers throughout, whereas earlier - * architectures use 32bit pointers in 32bit mode. - * - * We compute the base address for the fields based on: - * - the field size stored in the DS configuration - * - the relative field position - * - * In order to store additional information in the BTS buffer, we use - * a special source address to indicate that the record requires - * special interpretation. - * - * Netburst indicated via a bit in the flags field whether the branch - * was predicted; this is ignored. - * - * We use two levels of abstraction: - * - the raw data level defined here - * - an arch-independent level defined in ds.h - */ - -enum bts_field { - bts_from, - bts_to, - bts_flags, - - bts_qual = bts_from, - bts_clock = bts_to, - bts_pid = bts_flags, - - bts_qual_mask = (bts_qual_max - 1), - bts_escape = ((unsigned long)-1 & ~bts_qual_mask) -}; - -static inline unsigned long bts_get(const char *base, unsigned long field) -{ - base += (ds_cfg.sizeof_ptr_field * field); - return *(unsigned long *)base; -} - -static inline void bts_set(char *base, unsigned long field, unsigned long val) -{ - base += (ds_cfg.sizeof_ptr_field * field); - (*(unsigned long *)base) = val; -} - - -/* - * The raw BTS data is architecture dependent. - * - * For higher-level users, we give an arch-independent view. - * - ds.h defines struct bts_struct - * - bts_read translates one raw bts record into a bts_struct - * - bts_write translates one bts_struct into the raw format and - * writes it into the top of the parameter tracer's buffer. - * - * return: bytes read/written on success; -Eerrno, otherwise - */ -static int -bts_read(struct bts_tracer *tracer, const void *at, struct bts_struct *out) -{ - if (!tracer) - return -EINVAL; - - if (at < tracer->trace.ds.begin) - return -EINVAL; - - if (tracer->trace.ds.end < (at + tracer->trace.ds.size)) - return -EINVAL; - - memset(out, 0, sizeof(*out)); - if ((bts_get(at, bts_qual) & ~bts_qual_mask) == bts_escape) { - out->qualifier = (bts_get(at, bts_qual) & bts_qual_mask); - out->variant.event.clock = bts_get(at, bts_clock); - out->variant.event.pid = bts_get(at, bts_pid); - } else { - out->qualifier = bts_branch; - out->variant.lbr.from = bts_get(at, bts_from); - out->variant.lbr.to = bts_get(at, bts_to); - - if (!out->variant.lbr.from && !out->variant.lbr.to) - out->qualifier = bts_invalid; - } - - return ds_cfg.sizeof_rec[ds_bts]; -} - -static int bts_write(struct bts_tracer *tracer, const struct bts_struct *in) -{ - unsigned char raw[MAX_SIZEOF_BTS]; - - if (!tracer) - return -EINVAL; - - if (MAX_SIZEOF_BTS < ds_cfg.sizeof_rec[ds_bts]) - return -EOVERFLOW; - - switch (in->qualifier) { - case bts_invalid: - bts_set(raw, bts_from, 0); - bts_set(raw, bts_to, 0); - bts_set(raw, bts_flags, 0); - break; - case bts_branch: - bts_set(raw, bts_from, in->variant.lbr.from); - bts_set(raw, bts_to, in->variant.lbr.to); - bts_set(raw, bts_flags, 0); - break; - case bts_task_arrives: - case bts_task_departs: - bts_set(raw, bts_qual, (bts_escape | in->qualifier)); - bts_set(raw, bts_clock, in->variant.event.clock); - bts_set(raw, bts_pid, in->variant.event.pid); - break; - default: - return -EINVAL; - } - - return ds_write(tracer->ds.context, ds_bts, raw, - ds_cfg.sizeof_rec[ds_bts]); -} - - -static void ds_write_config(struct ds_context *context, - struct ds_trace *cfg, enum ds_qualifier qual) -{ - unsigned char *ds = context->ds; - - ds_set(ds, qual, ds_buffer_base, (unsigned long)cfg->begin); - ds_set(ds, qual, ds_index, (unsigned long)cfg->top); - ds_set(ds, qual, ds_absolute_maximum, (unsigned long)cfg->end); - ds_set(ds, qual, ds_interrupt_threshold, (unsigned long)cfg->ith); -} - -static void ds_read_config(struct ds_context *context, - struct ds_trace *cfg, enum ds_qualifier qual) -{ - unsigned char *ds = context->ds; - - cfg->begin = (void *)ds_get(ds, qual, ds_buffer_base); - cfg->top = (void *)ds_get(ds, qual, ds_index); - cfg->end = (void *)ds_get(ds, qual, ds_absolute_maximum); - cfg->ith = (void *)ds_get(ds, qual, ds_interrupt_threshold); -} - -static void ds_init_ds_trace(struct ds_trace *trace, enum ds_qualifier qual, - void *base, size_t size, size_t ith, - unsigned int flags) { - unsigned long buffer, adj; - - /* - * Adjust the buffer address and size to meet alignment - * constraints: - * - buffer is double-word aligned - * - size is multiple of record size - * - * We checked the size at the very beginning; we have enough - * space to do the adjustment. - */ - buffer = (unsigned long)base; - - adj = ALIGN(buffer, DS_ALIGNMENT) - buffer; - buffer += adj; - size -= adj; - - trace->n = size / ds_cfg.sizeof_rec[qual]; - trace->size = ds_cfg.sizeof_rec[qual]; - - size = (trace->n * trace->size); - - trace->begin = (void *)buffer; - trace->top = trace->begin; - trace->end = (void *)(buffer + size); - /* - * The value for 'no threshold' is -1, which will set the - * threshold outside of the buffer, just like we want it. - */ - ith *= ds_cfg.sizeof_rec[qual]; - trace->ith = (void *)(buffer + size - ith); - - trace->flags = flags; -} - - -static int ds_request(struct ds_tracer *tracer, struct ds_trace *trace, - enum ds_qualifier qual, struct task_struct *task, - int cpu, void *base, size_t size, size_t th) -{ - struct ds_context *context; - int error; - size_t req_size; - - error = -EOPNOTSUPP; - if (!ds_cfg.sizeof_rec[qual]) - goto out; - - error = -EINVAL; - if (!base) - goto out; - - req_size = ds_cfg.sizeof_rec[qual]; - /* We might need space for alignment adjustments. */ - if (!IS_ALIGNED((unsigned long)base, DS_ALIGNMENT)) - req_size += DS_ALIGNMENT; - - error = -EINVAL; - if (size < req_size) - goto out; - - if (th != (size_t)-1) { - th *= ds_cfg.sizeof_rec[qual]; - - error = -EINVAL; - if (size <= th) - goto out; - } - - tracer->buffer = base; - tracer->size = size; - - error = -ENOMEM; - context = ds_get_context(task, cpu); - if (!context) - goto out; - tracer->context = context; - - /* - * Defer any tracer-specific initialization work for the context until - * context ownership has been clarified. - */ - - error = 0; - out: - return error; -} - -static struct bts_tracer *ds_request_bts(struct task_struct *task, int cpu, - void *base, size_t size, - bts_ovfl_callback_t ovfl, size_t th, - unsigned int flags) -{ - struct bts_tracer *tracer; - int error; - - /* Buffer overflow notification is not yet implemented. */ - error = -EOPNOTSUPP; - if (ovfl) - goto out; - - error = get_tracer(task); - if (error < 0) - goto out; - - error = -ENOMEM; - tracer = kzalloc(sizeof(*tracer), GFP_KERNEL); - if (!tracer) - goto out_put_tracer; - tracer->ovfl = ovfl; - - /* Do some more error checking and acquire a tracing context. */ - error = ds_request(&tracer->ds, &tracer->trace.ds, - ds_bts, task, cpu, base, size, th); - if (error < 0) - goto out_tracer; - - /* Claim the bts part of the tracing context we acquired above. */ - spin_lock_irq(&ds_lock); - - error = -EPERM; - if (tracer->ds.context->bts_master) - goto out_unlock; - tracer->ds.context->bts_master = tracer; - - spin_unlock_irq(&ds_lock); - - /* - * Now that we own the bts part of the context, let's complete the - * initialization for that part. - */ - ds_init_ds_trace(&tracer->trace.ds, ds_bts, base, size, th, flags); - ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_bts); - ds_install_ds_area(tracer->ds.context); - - tracer->trace.read = bts_read; - tracer->trace.write = bts_write; - - /* Start tracing. */ - ds_resume_bts(tracer); - - return tracer; - - out_unlock: - spin_unlock_irq(&ds_lock); - ds_put_context(tracer->ds.context); - out_tracer: - kfree(tracer); - out_put_tracer: - put_tracer(task); - out: - return ERR_PTR(error); -} - -struct bts_tracer *ds_request_bts_task(struct task_struct *task, - void *base, size_t size, - bts_ovfl_callback_t ovfl, - size_t th, unsigned int flags) -{ - return ds_request_bts(task, 0, base, size, ovfl, th, flags); -} - -struct bts_tracer *ds_request_bts_cpu(int cpu, void *base, size_t size, - bts_ovfl_callback_t ovfl, - size_t th, unsigned int flags) -{ - return ds_request_bts(NULL, cpu, base, size, ovfl, th, flags); -} - -static struct pebs_tracer *ds_request_pebs(struct task_struct *task, int cpu, - void *base, size_t size, - pebs_ovfl_callback_t ovfl, size_t th, - unsigned int flags) -{ - struct pebs_tracer *tracer; - int error; - - /* Buffer overflow notification is not yet implemented. */ - error = -EOPNOTSUPP; - if (ovfl) - goto out; - - error = get_tracer(task); - if (error < 0) - goto out; - - error = -ENOMEM; - tracer = kzalloc(sizeof(*tracer), GFP_KERNEL); - if (!tracer) - goto out_put_tracer; - tracer->ovfl = ovfl; - - /* Do some more error checking and acquire a tracing context. */ - error = ds_request(&tracer->ds, &tracer->trace.ds, - ds_pebs, task, cpu, base, size, th); - if (error < 0) - goto out_tracer; - - /* Claim the pebs part of the tracing context we acquired above. */ - spin_lock_irq(&ds_lock); - - error = -EPERM; - if (tracer->ds.context->pebs_master) - goto out_unlock; - tracer->ds.context->pebs_master = tracer; - - spin_unlock_irq(&ds_lock); - - /* - * Now that we own the pebs part of the context, let's complete the - * initialization for that part. - */ - ds_init_ds_trace(&tracer->trace.ds, ds_pebs, base, size, th, flags); - ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_pebs); - ds_install_ds_area(tracer->ds.context); - - /* Start tracing. */ - ds_resume_pebs(tracer); - - return tracer; - - out_unlock: - spin_unlock_irq(&ds_lock); - ds_put_context(tracer->ds.context); - out_tracer: - kfree(tracer); - out_put_tracer: - put_tracer(task); - out: - return ERR_PTR(error); -} - -struct pebs_tracer *ds_request_pebs_task(struct task_struct *task, - void *base, size_t size, - pebs_ovfl_callback_t ovfl, - size_t th, unsigned int flags) -{ - return ds_request_pebs(task, 0, base, size, ovfl, th, flags); -} - -struct pebs_tracer *ds_request_pebs_cpu(int cpu, void *base, size_t size, - pebs_ovfl_callback_t ovfl, - size_t th, unsigned int flags) -{ - return ds_request_pebs(NULL, cpu, base, size, ovfl, th, flags); -} - -static void ds_free_bts(struct bts_tracer *tracer) -{ - struct task_struct *task; - - task = tracer->ds.context->task; - - WARN_ON_ONCE(tracer->ds.context->bts_master != tracer); - tracer->ds.context->bts_master = NULL; - - /* Make sure tracing stopped and the tracer is not in use. */ - if (task && (task != current)) - wait_task_context_switch(task); - - ds_put_context(tracer->ds.context); - put_tracer(task); - - kfree(tracer); -} - -void ds_release_bts(struct bts_tracer *tracer) -{ - might_sleep(); - - if (!tracer) - return; - - ds_suspend_bts(tracer); - ds_free_bts(tracer); -} - -int ds_release_bts_noirq(struct bts_tracer *tracer) -{ - struct task_struct *task; - unsigned long irq; - int error; - - if (!tracer) - return 0; - - task = tracer->ds.context->task; - - local_irq_save(irq); - - error = -EPERM; - if (!task && - (tracer->ds.context->cpu != smp_processor_id())) - goto out; - - error = -EPERM; - if (task && (task != current)) - goto out; - - ds_suspend_bts_noirq(tracer); - ds_free_bts(tracer); - - error = 0; - out: - local_irq_restore(irq); - return error; -} - -static void update_task_debugctlmsr(struct task_struct *task, - unsigned long debugctlmsr) -{ - task->thread.debugctlmsr = debugctlmsr; - - get_cpu(); - if (task == current) - update_debugctlmsr(debugctlmsr); - put_cpu(); -} - -void ds_suspend_bts(struct bts_tracer *tracer) -{ - struct task_struct *task; - unsigned long debugctlmsr; - int cpu; - - if (!tracer) - return; - - tracer->flags = 0; - - task = tracer->ds.context->task; - cpu = tracer->ds.context->cpu; - - WARN_ON(!task && irqs_disabled()); - - debugctlmsr = (task ? - task->thread.debugctlmsr : - get_debugctlmsr_on_cpu(cpu)); - debugctlmsr &= ~BTS_CONTROL; - - if (task) - update_task_debugctlmsr(task, debugctlmsr); - else - update_debugctlmsr_on_cpu(cpu, debugctlmsr); -} - -int ds_suspend_bts_noirq(struct bts_tracer *tracer) -{ - struct task_struct *task; - unsigned long debugctlmsr, irq; - int cpu, error = 0; - - if (!tracer) - return 0; - - tracer->flags = 0; - - task = tracer->ds.context->task; - cpu = tracer->ds.context->cpu; - - local_irq_save(irq); - - error = -EPERM; - if (!task && (cpu != smp_processor_id())) - goto out; - - debugctlmsr = (task ? - task->thread.debugctlmsr : - get_debugctlmsr()); - debugctlmsr &= ~BTS_CONTROL; - - if (task) - update_task_debugctlmsr(task, debugctlmsr); - else - update_debugctlmsr(debugctlmsr); - - error = 0; - out: - local_irq_restore(irq); - return error; -} - -static unsigned long ds_bts_control(struct bts_tracer *tracer) -{ - unsigned long control; - - control = ds_cfg.ctl[dsf_bts]; - if (!(tracer->trace.ds.flags & BTS_KERNEL)) - control |= ds_cfg.ctl[dsf_bts_kernel]; - if (!(tracer->trace.ds.flags & BTS_USER)) - control |= ds_cfg.ctl[dsf_bts_user]; - - return control; -} - -void ds_resume_bts(struct bts_tracer *tracer) -{ - struct task_struct *task; - unsigned long debugctlmsr; - int cpu; - - if (!tracer) - return; - - tracer->flags = tracer->trace.ds.flags; - - task = tracer->ds.context->task; - cpu = tracer->ds.context->cpu; - - WARN_ON(!task && irqs_disabled()); - - debugctlmsr = (task ? - task->thread.debugctlmsr : - get_debugctlmsr_on_cpu(cpu)); - debugctlmsr |= ds_bts_control(tracer); - - if (task) - update_task_debugctlmsr(task, debugctlmsr); - else - update_debugctlmsr_on_cpu(cpu, debugctlmsr); -} - -int ds_resume_bts_noirq(struct bts_tracer *tracer) -{ - struct task_struct *task; - unsigned long debugctlmsr, irq; - int cpu, error = 0; - - if (!tracer) - return 0; - - tracer->flags = tracer->trace.ds.flags; - - task = tracer->ds.context->task; - cpu = tracer->ds.context->cpu; - - local_irq_save(irq); - - error = -EPERM; - if (!task && (cpu != smp_processor_id())) - goto out; - - debugctlmsr = (task ? - task->thread.debugctlmsr : - get_debugctlmsr()); - debugctlmsr |= ds_bts_control(tracer); - - if (task) - update_task_debugctlmsr(task, debugctlmsr); - else - update_debugctlmsr(debugctlmsr); - - error = 0; - out: - local_irq_restore(irq); - return error; -} - -static void ds_free_pebs(struct pebs_tracer *tracer) -{ - struct task_struct *task; - - task = tracer->ds.context->task; - - WARN_ON_ONCE(tracer->ds.context->pebs_master != tracer); - tracer->ds.context->pebs_master = NULL; - - ds_put_context(tracer->ds.context); - put_tracer(task); - - kfree(tracer); -} - -void ds_release_pebs(struct pebs_tracer *tracer) -{ - might_sleep(); - - if (!tracer) - return; - - ds_suspend_pebs(tracer); - ds_free_pebs(tracer); -} - -int ds_release_pebs_noirq(struct pebs_tracer *tracer) -{ - struct task_struct *task; - unsigned long irq; - int error; - - if (!tracer) - return 0; - - task = tracer->ds.context->task; - - local_irq_save(irq); - - error = -EPERM; - if (!task && - (tracer->ds.context->cpu != smp_processor_id())) - goto out; - - error = -EPERM; - if (task && (task != current)) - goto out; - - ds_suspend_pebs_noirq(tracer); - ds_free_pebs(tracer); - - error = 0; - out: - local_irq_restore(irq); - return error; -} - -void ds_suspend_pebs(struct pebs_tracer *tracer) -{ - -} - -int ds_suspend_pebs_noirq(struct pebs_tracer *tracer) -{ - return 0; -} - -void ds_resume_pebs(struct pebs_tracer *tracer) -{ - -} - -int ds_resume_pebs_noirq(struct pebs_tracer *tracer) -{ - return 0; -} - -const struct bts_trace *ds_read_bts(struct bts_tracer *tracer) -{ - if (!tracer) - return NULL; - - ds_read_config(tracer->ds.context, &tracer->trace.ds, ds_bts); - return &tracer->trace; -} - -const struct pebs_trace *ds_read_pebs(struct pebs_tracer *tracer) -{ - if (!tracer) - return NULL; - - ds_read_config(tracer->ds.context, &tracer->trace.ds, ds_pebs); - - tracer->trace.counters = ds_cfg.nr_counter_reset; - memcpy(tracer->trace.counter_reset, - tracer->ds.context->ds + - (NUM_DS_PTR_FIELDS * ds_cfg.sizeof_ptr_field), - ds_cfg.nr_counter_reset * PEBS_RESET_FIELD_SIZE); - - return &tracer->trace; -} - -int ds_reset_bts(struct bts_tracer *tracer) -{ - if (!tracer) - return -EINVAL; - - tracer->trace.ds.top = tracer->trace.ds.begin; - - ds_set(tracer->ds.context->ds, ds_bts, ds_index, - (unsigned long)tracer->trace.ds.top); - - return 0; -} - -int ds_reset_pebs(struct pebs_tracer *tracer) -{ - if (!tracer) - return -EINVAL; - - tracer->trace.ds.top = tracer->trace.ds.begin; - - ds_set(tracer->ds.context->ds, ds_pebs, ds_index, - (unsigned long)tracer->trace.ds.top); - - return 0; -} - -int ds_set_pebs_reset(struct pebs_tracer *tracer, - unsigned int counter, u64 value) -{ - if (!tracer) - return -EINVAL; - - if (ds_cfg.nr_counter_reset < counter) - return -EINVAL; - - *(u64 *)(tracer->ds.context->ds + - (NUM_DS_PTR_FIELDS * ds_cfg.sizeof_ptr_field) + - (counter * PEBS_RESET_FIELD_SIZE)) = value; - - return 0; -} - -static const struct ds_configuration ds_cfg_netburst = { - .name = "Netburst", - .ctl[dsf_bts] = (1 << 2) | (1 << 3), - .ctl[dsf_bts_kernel] = (1 << 5), - .ctl[dsf_bts_user] = (1 << 6), - .nr_counter_reset = 1, -}; -static const struct ds_configuration ds_cfg_pentium_m = { - .name = "Pentium M", - .ctl[dsf_bts] = (1 << 6) | (1 << 7), - .nr_counter_reset = 1, -}; -static const struct ds_configuration ds_cfg_core2_atom = { - .name = "Core 2/Atom", - .ctl[dsf_bts] = (1 << 6) | (1 << 7), - .ctl[dsf_bts_kernel] = (1 << 9), - .ctl[dsf_bts_user] = (1 << 10), - .nr_counter_reset = 1, -}; -static const struct ds_configuration ds_cfg_core_i7 = { - .name = "Core i7", - .ctl[dsf_bts] = (1 << 6) | (1 << 7), - .ctl[dsf_bts_kernel] = (1 << 9), - .ctl[dsf_bts_user] = (1 << 10), - .nr_counter_reset = 4, -}; - -static void -ds_configure(const struct ds_configuration *cfg, - struct cpuinfo_x86 *cpu) -{ - unsigned long nr_pebs_fields = 0; - - printk(KERN_INFO "[ds] using %s configuration\n", cfg->name); - -#ifdef __i386__ - nr_pebs_fields = 10; -#else - nr_pebs_fields = 18; -#endif - - /* - * Starting with version 2, architectural performance - * monitoring supports a format specifier. - */ - if ((cpuid_eax(0xa) & 0xff) > 1) { - unsigned long perf_capabilities, format; - - rdmsrl(MSR_IA32_PERF_CAPABILITIES, perf_capabilities); - - format = (perf_capabilities >> 8) & 0xf; - - switch (format) { - case 0: - nr_pebs_fields = 18; - break; - case 1: - nr_pebs_fields = 22; - break; - default: - printk(KERN_INFO - "[ds] unknown PEBS format: %lu\n", format); - nr_pebs_fields = 0; - break; - } - } - - memset(&ds_cfg, 0, sizeof(ds_cfg)); - ds_cfg = *cfg; - - ds_cfg.sizeof_ptr_field = - (cpu_has(cpu, X86_FEATURE_DTES64) ? 8 : 4); - - ds_cfg.sizeof_rec[ds_bts] = ds_cfg.sizeof_ptr_field * 3; - ds_cfg.sizeof_rec[ds_pebs] = ds_cfg.sizeof_ptr_field * nr_pebs_fields; - - if (!cpu_has(cpu, X86_FEATURE_BTS)) { - ds_cfg.sizeof_rec[ds_bts] = 0; - printk(KERN_INFO "[ds] bts not available\n"); - } - if (!cpu_has(cpu, X86_FEATURE_PEBS)) { - ds_cfg.sizeof_rec[ds_pebs] = 0; - printk(KERN_INFO "[ds] pebs not available\n"); - } - - printk(KERN_INFO "[ds] sizes: address: %u bit, ", - 8 * ds_cfg.sizeof_ptr_field); - printk("bts/pebs record: %u/%u bytes\n", - ds_cfg.sizeof_rec[ds_bts], ds_cfg.sizeof_rec[ds_pebs]); - - WARN_ON_ONCE(MAX_PEBS_COUNTERS < ds_cfg.nr_counter_reset); -} - -void __cpuinit ds_init_intel(struct cpuinfo_x86 *c) -{ - /* Only configure the first cpu. Others are identical. */ - if (ds_cfg.name) - return; - - switch (c->x86) { - case 0x6: - switch (c->x86_model) { - case 0x9: - case 0xd: /* Pentium M */ - ds_configure(&ds_cfg_pentium_m, c); - break; - case 0xf: - case 0x17: /* Core2 */ - case 0x1c: /* Atom */ - ds_configure(&ds_cfg_core2_atom, c); - break; - case 0x1a: /* Core i7 */ - ds_configure(&ds_cfg_core_i7, c); - break; - default: - /* Sorry, don't know about them. */ - break; - } - break; - case 0xf: - switch (c->x86_model) { - case 0x0: - case 0x1: - case 0x2: /* Netburst */ - ds_configure(&ds_cfg_netburst, c); - break; - default: - /* Sorry, don't know about them. */ - break; - } - break; - default: - /* Sorry, don't know about them. */ - break; - } -} - -static inline void ds_take_timestamp(struct ds_context *context, - enum bts_qualifier qualifier, - struct task_struct *task) -{ - struct bts_tracer *tracer = context->bts_master; - struct bts_struct ts; - - /* Prevent compilers from reading the tracer pointer twice. */ - barrier(); - - if (!tracer || !(tracer->flags & BTS_TIMESTAMPS)) - return; - - memset(&ts, 0, sizeof(ts)); - ts.qualifier = qualifier; - ts.variant.event.clock = trace_clock_global(); - ts.variant.event.pid = task->pid; - - bts_write(tracer, &ts); -} - -/* - * Change the DS configuration from tracing prev to tracing next. - */ -void ds_switch_to(struct task_struct *prev, struct task_struct *next) -{ - struct ds_context *prev_ctx = prev->thread.ds_ctx; - struct ds_context *next_ctx = next->thread.ds_ctx; - unsigned long debugctlmsr = next->thread.debugctlmsr; - - /* Make sure all data is read before we start. */ - barrier(); - - if (prev_ctx) { - update_debugctlmsr(0); - - ds_take_timestamp(prev_ctx, bts_task_departs, prev); - } - - if (next_ctx) { - ds_take_timestamp(next_ctx, bts_task_arrives, next); - - wrmsrl(MSR_IA32_DS_AREA, (unsigned long)next_ctx->ds); - } - - update_debugctlmsr(debugctlmsr); -} - -static __init int ds_selftest(void) -{ - if (ds_cfg.sizeof_rec[ds_bts]) { - int error; - - error = ds_selftest_bts(); - if (error) { - WARN(1, "[ds] selftest failed. disabling bts.\n"); - ds_cfg.sizeof_rec[ds_bts] = 0; - } - } - - if (ds_cfg.sizeof_rec[ds_pebs]) { - int error; - - error = ds_selftest_pebs(); - if (error) { - WARN(1, "[ds] selftest failed. disabling pebs.\n"); - ds_cfg.sizeof_rec[ds_pebs] = 0; - } - } - - return 0; -} -device_initcall(ds_selftest); diff --git a/arch/x86/kernel/ds_selftest.c b/arch/x86/kernel/ds_selftest.c deleted file mode 100644 index 6bc7c199ab9..00000000000 --- a/arch/x86/kernel/ds_selftest.c +++ /dev/null @@ -1,408 +0,0 @@ -/* - * Debug Store support - selftest - * - * - * Copyright (C) 2009 Intel Corporation. - * Markus Metzger , 2009 - */ - -#include "ds_selftest.h" - -#include -#include -#include -#include - -#include - - -#define BUFFER_SIZE 521 /* Intentionally chose an odd size. */ -#define SMALL_BUFFER_SIZE 24 /* A single bts entry. */ - -struct ds_selftest_bts_conf { - struct bts_tracer *tracer; - int error; - int (*suspend)(struct bts_tracer *); - int (*resume)(struct bts_tracer *); -}; - -static int ds_selftest_bts_consistency(const struct bts_trace *trace) -{ - int error = 0; - - if (!trace) { - printk(KERN_CONT "failed to access trace..."); - /* Bail out. Other tests are pointless. */ - return -1; - } - - if (!trace->read) { - printk(KERN_CONT "bts read not available..."); - error = -1; - } - - /* Do some sanity checks on the trace configuration. */ - if (!trace->ds.n) { - printk(KERN_CONT "empty bts buffer..."); - error = -1; - } - if (!trace->ds.size) { - printk(KERN_CONT "bad bts trace setup..."); - error = -1; - } - if (trace->ds.end != - (char *)trace->ds.begin + (trace->ds.n * trace->ds.size)) { - printk(KERN_CONT "bad bts buffer setup..."); - error = -1; - } - /* - * We allow top in [begin; end], since its not clear when the - * overflow adjustment happens: after the increment or before the - * write. - */ - if ((trace->ds.top < trace->ds.begin) || - (trace->ds.end < trace->ds.top)) { - printk(KERN_CONT "bts top out of bounds..."); - error = -1; - } - - return error; -} - -static int ds_selftest_bts_read(struct bts_tracer *tracer, - const struct bts_trace *trace, - const void *from, const void *to) -{ - const unsigned char *at; - - /* - * Check a few things which do not belong to this test. - * They should be covered by other tests. - */ - if (!trace) - return -1; - - if (!trace->read) - return -1; - - if (to < from) - return -1; - - if (from < trace->ds.begin) - return -1; - - if (trace->ds.end < to) - return -1; - - if (!trace->ds.size) - return -1; - - /* Now to the test itself. */ - for (at = from; (void *)at < to; at += trace->ds.size) { - struct bts_struct bts; - unsigned long index; - int error; - - if (((void *)at - trace->ds.begin) % trace->ds.size) { - printk(KERN_CONT - "read from non-integer index..."); - return -1; - } - index = ((void *)at - trace->ds.begin) / trace->ds.size; - - memset(&bts, 0, sizeof(bts)); - error = trace->read(tracer, at, &bts); - if (error < 0) { - printk(KERN_CONT - "error reading bts trace at [%lu] (0x%p)...", - index, at); - return error; - } - - switch (bts.qualifier) { - case BTS_BRANCH: - break; - default: - printk(KERN_CONT - "unexpected bts entry %llu at [%lu] (0x%p)...", - bts.qualifier, index, at); - return -1; - } - } - - return 0; -} - -static void ds_selftest_bts_cpu(void *arg) -{ - struct ds_selftest_bts_conf *conf = arg; - const struct bts_trace *trace; - void *top; - - if (IS_ERR(conf->tracer)) { - conf->error = PTR_ERR(conf->tracer); - conf->tracer = NULL; - - printk(KERN_CONT - "initialization failed (err: %d)...", conf->error); - return; - } - - /* We should meanwhile have enough trace. */ - conf->error = conf->suspend(conf->tracer); - if (conf->error < 0) - return; - - /* Let's see if we can access the trace. */ - trace = ds_read_bts(conf->tracer); - - conf->error = ds_selftest_bts_consistency(trace); - if (conf->error < 0) - return; - - /* If everything went well, we should have a few trace entries. */ - if (trace->ds.top == trace->ds.begin) { - /* - * It is possible but highly unlikely that we got a - * buffer overflow and end up at exactly the same - * position we started from. - * Let's issue a warning, but continue. - */ - printk(KERN_CONT "no trace/overflow..."); - } - - /* Let's try to read the trace we collected. */ - conf->error = - ds_selftest_bts_read(conf->tracer, trace, - trace->ds.begin, trace->ds.top); - if (conf->error < 0) - return; - - /* - * Let's read the trace again. - * Since we suspended tracing, we should get the same result. - */ - top = trace->ds.top; - - trace = ds_read_bts(conf->tracer); - conf->error = ds_selftest_bts_consistency(trace); - if (conf->error < 0) - return; - - if (top != trace->ds.top) { - printk(KERN_CONT "suspend not working..."); - conf->error = -1; - return; - } - - /* Let's collect some more trace - see if resume is working. */ - conf->error = conf->resume(conf->tracer); - if (conf->error < 0) - return; - - conf->error = conf->suspend(conf->tracer); - if (conf->error < 0) - return; - - trace = ds_read_bts(conf->tracer); - - conf->error = ds_selftest_bts_consistency(trace); - if (conf->error < 0) - return; - - if (trace->ds.top == top) { - /* - * It is possible but highly unlikely that we got a - * buffer overflow and end up at exactly the same - * position we started from. - * Let's issue a warning and check the full trace. - */ - printk(KERN_CONT - "no resume progress/overflow..."); - - conf->error = - ds_selftest_bts_read(conf->tracer, trace, - trace->ds.begin, trace->ds.end); - } else if (trace->ds.top < top) { - /* - * We had a buffer overflow - the entire buffer should - * contain trace records. - */ - conf->error = - ds_selftest_bts_read(conf->tracer, trace, - trace->ds.begin, trace->ds.end); - } else { - /* - * It is quite likely that the buffer did not overflow. - * Let's just check the delta trace. - */ - conf->error = - ds_selftest_bts_read(conf->tracer, trace, top, - trace->ds.top); - } - if (conf->error < 0) - return; - - conf->error = 0; -} - -static int ds_suspend_bts_wrap(struct bts_tracer *tracer) -{ - ds_suspend_bts(tracer); - return 0; -} - -static int ds_resume_bts_wrap(struct bts_tracer *tracer) -{ - ds_resume_bts(tracer); - return 0; -} - -static void ds_release_bts_noirq_wrap(void *tracer) -{ - (void)ds_release_bts_noirq(tracer); -} - -static int ds_selftest_bts_bad_release_noirq(int cpu, - struct bts_tracer *tracer) -{ - int error = -EPERM; - - /* Try to release the tracer on the wrong cpu. */ - get_cpu(); - if (cpu != smp_processor_id()) { - error = ds_release_bts_noirq(tracer); - if (error != -EPERM) - printk(KERN_CONT "release on wrong cpu..."); - } - put_cpu(); - - return error ? 0 : -1; -} - -static int ds_selftest_bts_bad_request_cpu(int cpu, void *buffer) -{ - struct bts_tracer *tracer; - int error; - - /* Try to request cpu tracing while task tracing is active. */ - tracer = ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE, NULL, - (size_t)-1, BTS_KERNEL); - error = PTR_ERR(tracer); - if (!IS_ERR(tracer)) { - ds_release_bts(tracer); - error = 0; - } - - if (error != -EPERM) - printk(KERN_CONT "cpu/task tracing overlap..."); - - return error ? 0 : -1; -} - -static int ds_selftest_bts_bad_request_task(void *buffer) -{ - struct bts_tracer *tracer; - int error; - - /* Try to request cpu tracing while task tracing is active. */ - tracer = ds_request_bts_task(current, buffer, BUFFER_SIZE, NULL, - (size_t)-1, BTS_KERNEL); - error = PTR_ERR(tracer); - if (!IS_ERR(tracer)) { - error = 0; - ds_release_bts(tracer); - } - - if (error != -EPERM) - printk(KERN_CONT "task/cpu tracing overlap..."); - - return error ? 0 : -1; -} - -int ds_selftest_bts(void) -{ - struct ds_selftest_bts_conf conf; - unsigned char buffer[BUFFER_SIZE], *small_buffer; - unsigned long irq; - int cpu; - - printk(KERN_INFO "[ds] bts selftest..."); - conf.error = 0; - - small_buffer = (unsigned char *)ALIGN((unsigned long)buffer, 8) + 8; - - get_online_cpus(); - for_each_online_cpu(cpu) { - conf.suspend = ds_suspend_bts_wrap; - conf.resume = ds_resume_bts_wrap; - conf.tracer = - ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE, - NULL, (size_t)-1, BTS_KERNEL); - ds_selftest_bts_cpu(&conf); - if (conf.error >= 0) - conf.error = ds_selftest_bts_bad_request_task(buffer); - ds_release_bts(conf.tracer); - if (conf.error < 0) - goto out; - - conf.suspend = ds_suspend_bts_noirq; - conf.resume = ds_resume_bts_noirq; - conf.tracer = - ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE, - NULL, (size_t)-1, BTS_KERNEL); - smp_call_function_single(cpu, ds_selftest_bts_cpu, &conf, 1); - if (conf.error >= 0) { - conf.error = - ds_selftest_bts_bad_release_noirq(cpu, - conf.tracer); - /* We must not release the tracer twice. */ - if (conf.error < 0) - conf.tracer = NULL; - } - if (conf.error >= 0) - conf.error = ds_selftest_bts_bad_request_task(buffer); - smp_call_function_single(cpu, ds_release_bts_noirq_wrap, - conf.tracer, 1); - if (conf.error < 0) - goto out; - } - - conf.suspend = ds_suspend_bts_wrap; - conf.resume = ds_resume_bts_wrap; - conf.tracer = - ds_request_bts_task(current, buffer, BUFFER_SIZE, - NULL, (size_t)-1, BTS_KERNEL); - ds_selftest_bts_cpu(&conf); - if (conf.error >= 0) - conf.error = ds_selftest_bts_bad_request_cpu(0, buffer); - ds_release_bts(conf.tracer); - if (conf.error < 0) - goto out; - - conf.suspend = ds_suspend_bts_noirq; - conf.resume = ds_resume_bts_noirq; - conf.tracer = - ds_request_bts_task(current, small_buffer, SMALL_BUFFER_SIZE, - NULL, (size_t)-1, BTS_KERNEL); - local_irq_save(irq); - ds_selftest_bts_cpu(&conf); - if (conf.error >= 0) - conf.error = ds_selftest_bts_bad_request_cpu(0, buffer); - ds_release_bts_noirq(conf.tracer); - local_irq_restore(irq); - if (conf.error < 0) - goto out; - - conf.error = 0; - out: - put_online_cpus(); - printk(KERN_CONT "%s.\n", (conf.error ? "failed" : "passed")); - - return conf.error; -} - -int ds_selftest_pebs(void) -{ - return 0; -} diff --git a/arch/x86/kernel/ds_selftest.h b/arch/x86/kernel/ds_selftest.h deleted file mode 100644 index 2ba8745c666..00000000000 --- a/arch/x86/kernel/ds_selftest.h +++ /dev/null @@ -1,15 +0,0 @@ -/* - * Debug Store support - selftest - * - * - * Copyright (C) 2009 Intel Corporation. - * Markus Metzger , 2009 - */ - -#ifdef CONFIG_X86_DS_SELFTEST -extern int ds_selftest_bts(void); -extern int ds_selftest_pebs(void); -#else -static inline int ds_selftest_bts(void) { return 0; } -static inline int ds_selftest_pebs(void) { return 0; } -#endif diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 6d817554780..c89a386930b 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -224,11 +224,6 @@ unsigned __kprobes long oops_begin(void) int cpu; unsigned long flags; - /* notify the hw-branch tracer so it may disable tracing and - add the last trace to the trace buffer - - the earlier this happens, the more useful the trace. */ - trace_hw_branch_oops(); - oops_enter(); /* racy, but better than risking deadlock. */ diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c index b43bbaebe2c..7a880ad3a20 100644 --- a/arch/x86/kernel/kprobes.c +++ b/arch/x86/kernel/kprobes.c @@ -422,14 +422,12 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, static void __kprobes clear_btf(void) { - if (test_thread_flag(TIF_DEBUGCTLMSR)) - update_debugctlmsr(0); + /* XXX */ } static void __kprobes restore_btf(void) { - if (test_thread_flag(TIF_DEBUGCTLMSR)) - update_debugctlmsr(current->thread.debugctlmsr); + /* XXX */ } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index ad9540676fc..1a60beb32ed 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -20,7 +20,6 @@ #include #include #include -#include #include unsigned long idle_halt; @@ -50,8 +49,6 @@ void free_thread_xstate(struct task_struct *tsk) kmem_cache_free(task_xstate_cachep, tsk->thread.xstate); tsk->thread.xstate = NULL; } - - WARN(tsk->thread.ds_ctx, "leaking DS context\n"); } void free_thread_info(struct thread_info *ti) @@ -198,12 +195,6 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, prev = &prev_p->thread; next = &next_p->thread; - if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) || - test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR)) - ds_switch_to(prev_p, next_p); - else if (next->debugctlmsr != prev->debugctlmsr) - update_debugctlmsr(next->debugctlmsr); - if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^ test_tsk_thread_flag(next_p, TIF_NOTSC)) { /* prev and next are different */ diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index f6c62667e30..75090c589b7 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -55,7 +55,6 @@ #include #include #include -#include #include asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); @@ -238,13 +237,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, kfree(p->thread.io_bitmap_ptr); p->thread.io_bitmap_max = 0; } - - clear_tsk_thread_flag(p, TIF_DS_AREA_MSR); - p->thread.ds_ctx = NULL; - - clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR); - p->thread.debugctlmsr = 0; - return err; } diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index dc9690b4c4c..cc4258f2beb 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -49,7 +49,6 @@ #include #include #include -#include #include asmlinkage extern void ret_from_fork(void); @@ -313,13 +312,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, if (err) goto out; } - - clear_tsk_thread_flag(p, TIF_DS_AREA_MSR); - p->thread.ds_ctx = NULL; - - clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR); - p->thread.debugctlmsr = 0; - err = 0; out: if (err && p->thread.io_bitmap_ptr) { diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index a503b1fd04e..f2fd3b80e56 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -2,9 +2,6 @@ /* * Pentium III FXSR, SSE support * Gareth Hughes , May 2000 - * - * BTS tracing - * Markus Metzger , Dec 2007 */ #include @@ -21,7 +18,6 @@ #include #include #include -#include #include #include @@ -35,7 +31,6 @@ #include #include #include -#include #include #include "tls.h" @@ -788,342 +783,6 @@ static int ioperm_get(struct task_struct *target, 0, IO_BITMAP_BYTES); } -#ifdef CONFIG_X86_PTRACE_BTS -/* - * A branch trace store context. - * - * Contexts may only be installed by ptrace_bts_config() and only for - * ptraced tasks. - * - * Contexts are destroyed when the tracee is detached from the tracer. - * The actual destruction work requires interrupts enabled, so the - * work is deferred and will be scheduled during __ptrace_unlink(). - * - * Contexts hold an additional task_struct reference on the traced - * task, as well as a reference on the tracer's mm. - * - * Ptrace already holds a task_struct for the duration of ptrace operations, - * but since destruction is deferred, it may be executed after both - * tracer and tracee exited. - */ -struct bts_context { - /* The branch trace handle. */ - struct bts_tracer *tracer; - - /* The buffer used to store the branch trace and its size. */ - void *buffer; - unsigned int size; - - /* The mm that paid for the above buffer. */ - struct mm_struct *mm; - - /* The task this context belongs to. */ - struct task_struct *task; - - /* The signal to send on a bts buffer overflow. */ - unsigned int bts_ovfl_signal; - - /* The work struct to destroy a context. */ - struct work_struct work; -}; - -static int alloc_bts_buffer(struct bts_context *context, unsigned int size) -{ - void *buffer = NULL; - int err = -ENOMEM; - - err = account_locked_memory(current->mm, current->signal->rlim, size); - if (err < 0) - return err; - - buffer = kzalloc(size, GFP_KERNEL); - if (!buffer) - goto out_refund; - - context->buffer = buffer; - context->size = size; - context->mm = get_task_mm(current); - - return 0; - - out_refund: - refund_locked_memory(current->mm, size); - return err; -} - -static inline void free_bts_buffer(struct bts_context *context) -{ - if (!context->buffer) - return; - - kfree(context->buffer); - context->buffer = NULL; - - refund_locked_memory(context->mm, context->size); - context->size = 0; - - mmput(context->mm); - context->mm = NULL; -} - -static void free_bts_context_work(struct work_struct *w) -{ - struct bts_context *context; - - context = container_of(w, struct bts_context, work); - - ds_release_bts(context->tracer); - put_task_struct(context->task); - free_bts_buffer(context); - kfree(context); -} - -static inline void free_bts_context(struct bts_context *context) -{ - INIT_WORK(&context->work, free_bts_context_work); - schedule_work(&context->work); -} - -static inline struct bts_context *alloc_bts_context(struct task_struct *task) -{ - struct bts_context *context = kzalloc(sizeof(*context), GFP_KERNEL); - if (context) { - context->task = task; - task->bts = context; - - get_task_struct(task); - } - - return context; -} - -static int ptrace_bts_read_record(struct task_struct *child, size_t index, - struct bts_struct __user *out) -{ - struct bts_context *context; - const struct bts_trace *trace; - struct bts_struct bts; - const unsigned char *at; - int error; - - context = child->bts; - if (!context) - return -ESRCH; - - trace = ds_read_bts(context->tracer); - if (!trace) - return -ESRCH; - - at = trace->ds.top - ((index + 1) * trace->ds.size); - if ((void *)at < trace->ds.begin) - at += (trace->ds.n * trace->ds.size); - - if (!trace->read) - return -EOPNOTSUPP; - - error = trace->read(context->tracer, at, &bts); - if (error < 0) - return error; - - if (copy_to_user(out, &bts, sizeof(bts))) - return -EFAULT; - - return sizeof(bts); -} - -static int ptrace_bts_drain(struct task_struct *child, - long size, - struct bts_struct __user *out) -{ - struct bts_context *context; - const struct bts_trace *trace; - const unsigned char *at; - int error, drained = 0; - - context = child->bts; - if (!context) - return -ESRCH; - - trace = ds_read_bts(context->tracer); - if (!trace) - return -ESRCH; - - if (!trace->read) - return -EOPNOTSUPP; - - if (size < (trace->ds.top - trace->ds.begin)) - return -EIO; - - for (at = trace->ds.begin; (void *)at < trace->ds.top; - out++, drained++, at += trace->ds.size) { - struct bts_struct bts; - - error = trace->read(context->tracer, at, &bts); - if (error < 0) - return error; - - if (copy_to_user(out, &bts, sizeof(bts))) - return -EFAULT; - } - - memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size); - - error = ds_reset_bts(context->tracer); - if (error < 0) - return error; - - return drained; -} - -static int ptrace_bts_config(struct task_struct *child, - long cfg_size, - const struct ptrace_bts_config __user *ucfg) -{ - struct bts_context *context; - struct ptrace_bts_config cfg; - unsigned int flags = 0; - - if (cfg_size < sizeof(cfg)) - return -EIO; - - if (copy_from_user(&cfg, ucfg, sizeof(cfg))) - return -EFAULT; - - context = child->bts; - if (!context) - context = alloc_bts_context(child); - if (!context) - return -ENOMEM; - - if (cfg.flags & PTRACE_BTS_O_SIGNAL) { - if (!cfg.signal) - return -EINVAL; - - return -EOPNOTSUPP; - context->bts_ovfl_signal = cfg.signal; - } - - ds_release_bts(context->tracer); - context->tracer = NULL; - - if ((cfg.flags & PTRACE_BTS_O_ALLOC) && (cfg.size != context->size)) { - int err; - - free_bts_buffer(context); - if (!cfg.size) - return 0; - - err = alloc_bts_buffer(context, cfg.size); - if (err < 0) - return err; - } - - if (cfg.flags & PTRACE_BTS_O_TRACE) - flags |= BTS_USER; - - if (cfg.flags & PTRACE_BTS_O_SCHED) - flags |= BTS_TIMESTAMPS; - - context->tracer = - ds_request_bts_task(child, context->buffer, context->size, - NULL, (size_t)-1, flags); - if (unlikely(IS_ERR(context->tracer))) { - int error = PTR_ERR(context->tracer); - - free_bts_buffer(context); - context->tracer = NULL; - return error; - } - - return sizeof(cfg); -} - -static int ptrace_bts_status(struct task_struct *child, - long cfg_size, - struct ptrace_bts_config __user *ucfg) -{ - struct bts_context *context; - const struct bts_trace *trace; - struct ptrace_bts_config cfg; - - context = child->bts; - if (!context) - return -ESRCH; - - if (cfg_size < sizeof(cfg)) - return -EIO; - - trace = ds_read_bts(context->tracer); - if (!trace) - return -ESRCH; - - memset(&cfg, 0, sizeof(cfg)); - cfg.size = trace->ds.end - trace->ds.begin; - cfg.signal = context->bts_ovfl_signal; - cfg.bts_size = sizeof(struct bts_struct); - - if (cfg.signal) - cfg.flags |= PTRACE_BTS_O_SIGNAL; - - if (trace->ds.flags & BTS_USER) - cfg.flags |= PTRACE_BTS_O_TRACE; - - if (trace->ds.flags & BTS_TIMESTAMPS) - cfg.flags |= PTRACE_BTS_O_SCHED; - - if (copy_to_user(ucfg, &cfg, sizeof(cfg))) - return -EFAULT; - - return sizeof(cfg); -} - -static int ptrace_bts_clear(struct task_struct *child) -{ - struct bts_context *context; - const struct bts_trace *trace; - - context = child->bts; - if (!context) - return -ESRCH; - - trace = ds_read_bts(context->tracer); - if (!trace) - return -ESRCH; - - memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size); - - return ds_reset_bts(context->tracer); -} - -static int ptrace_bts_size(struct task_struct *child) -{ - struct bts_context *context; - const struct bts_trace *trace; - - context = child->bts; - if (!context) - return -ESRCH; - - trace = ds_read_bts(context->tracer); - if (!trace) - return -ESRCH; - - return (trace->ds.top - trace->ds.begin) / trace->ds.size; -} - -/* - * Called from __ptrace_unlink() after the child has been moved back - * to its original parent. - */ -void ptrace_bts_untrace(struct task_struct *child) -{ - if (unlikely(child->bts)) { - free_bts_context(child->bts); - child->bts = NULL; - } -} -#endif /* CONFIG_X86_PTRACE_BTS */ - /* * Called by kernel/ptrace.c when detaching.. * @@ -1251,39 +910,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) break; #endif - /* - * These bits need more cooking - not enabled yet: - */ -#ifdef CONFIG_X86_PTRACE_BTS - case PTRACE_BTS_CONFIG: - ret = ptrace_bts_config - (child, data, (struct ptrace_bts_config __user *)addr); - break; - - case PTRACE_BTS_STATUS: - ret = ptrace_bts_status - (child, data, (struct ptrace_bts_config __user *)addr); - break; - - case PTRACE_BTS_SIZE: - ret = ptrace_bts_size(child); - break; - - case PTRACE_BTS_GET: - ret = ptrace_bts_read_record - (child, data, (struct bts_struct __user *) addr); - break; - - case PTRACE_BTS_CLEAR: - ret = ptrace_bts_clear(child); - break; - - case PTRACE_BTS_DRAIN: - ret = ptrace_bts_drain - (child, data, (struct bts_struct __user *) addr); - break; -#endif /* CONFIG_X86_PTRACE_BTS */ - default: ret = ptrace_request(child, request, addr, data); break; @@ -1543,14 +1169,6 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, case PTRACE_GET_THREAD_AREA: case PTRACE_SET_THREAD_AREA: -#ifdef CONFIG_X86_PTRACE_BTS - case PTRACE_BTS_CONFIG: - case PTRACE_BTS_STATUS: - case PTRACE_BTS_SIZE: - case PTRACE_BTS_GET: - case PTRACE_BTS_CLEAR: - case PTRACE_BTS_DRAIN: -#endif /* CONFIG_X86_PTRACE_BTS */ return arch_ptrace(child, request, addr, data); default: diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c index 3149032ff10..7beba0769a8 100644 --- a/arch/x86/kernel/step.c +++ b/arch/x86/kernel/step.c @@ -157,22 +157,6 @@ static int enable_single_step(struct task_struct *child) return 1; } -/* - * Install this value in MSR_IA32_DEBUGCTLMSR whenever child is running. - */ -static void write_debugctlmsr(struct task_struct *child, unsigned long val) -{ - if (child->thread.debugctlmsr == val) - return; - - child->thread.debugctlmsr = val; - - if (child != current) - return; - - update_debugctlmsr(val); -} - /* * Enable single or block step. */ @@ -185,17 +169,9 @@ static void enable_step(struct task_struct *child, bool block) * So noone should try to use debugger block stepping in a program * that uses user-mode single stepping itself. */ - if (enable_single_step(child) && block) { - set_tsk_thread_flag(child, TIF_DEBUGCTLMSR); - write_debugctlmsr(child, - child->thread.debugctlmsr | DEBUGCTLMSR_BTF); - } else { - write_debugctlmsr(child, - child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF); - - if (!child->thread.debugctlmsr) - clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR); - } + if (!enable_single_step(child)) + return; + /* XXX */ } void user_enable_single_step(struct task_struct *child) @@ -213,11 +189,7 @@ void user_disable_single_step(struct task_struct *child) /* * Make sure block stepping (BTF) is disabled. */ - write_debugctlmsr(child, - child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF); - - if (!child->thread.debugctlmsr) - clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR); + /* XXX */ /* Always clear TIF_SINGLESTEP... */ clear_tsk_thread_flag(child, TIF_SINGLESTEP); diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 1168e445418..e3da5d726a3 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -543,11 +543,6 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) /* DR6 may or may not be cleared by the CPU */ set_debugreg(0, 6); - /* - * The processor cleared BTF, so don't mark that we need it set. - */ - clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR); - tsk->thread.debugctlmsr = 0; /* Store the virtualized DR6 value */ tsk->thread.debugreg6 = dr6; diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 01e6adea07e..cc12b3c556b 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -504,18 +504,6 @@ extern int ftrace_dump_on_oops; #define INIT_TRACE_RECURSION #endif -#ifdef CONFIG_HW_BRANCH_TRACER - -void trace_hw_branch(u64 from, u64 to); -void trace_hw_branch_oops(void); - -#else /* CONFIG_HW_BRANCH_TRACER */ - -static inline void trace_hw_branch(u64 from, u64 to) {} -static inline void trace_hw_branch_oops(void) {} - -#endif /* CONFIG_HW_BRANCH_TRACER */ - #ifdef CONFIG_FTRACE_SYSCALLS unsigned long arch_syscall_addr(int nr); diff --git a/include/linux/mm.h b/include/linux/mm.h index e70f21beb4b..c8442b65511 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -19,7 +19,6 @@ struct anon_vma; struct file_ra_state; struct user_struct; struct writeback_control; -struct rlimit; #ifndef CONFIG_DISCONTIGMEM /* Don't use mapnrs, do it properly */ extern unsigned long max_mapnr; @@ -1449,9 +1448,6 @@ int vmemmap_populate_basepages(struct page *start_page, int vmemmap_populate(struct page *start_page, unsigned long pages, int node); void vmemmap_populate_print_last(void); -extern int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim, - size_t size); -extern void refund_locked_memory(struct mm_struct *mm, size_t size); enum mf_flags { MF_COUNT_INCREASED = 1 << 0, diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index e1fb6072997..4272521e29e 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -345,18 +345,6 @@ static inline void user_single_step_siginfo(struct task_struct *tsk, #define arch_ptrace_stop(code, info) do { } while (0) #endif -#ifndef arch_ptrace_untrace -/* - * Do machine-specific work before untracing child. - * - * This is called for a normal detach as well as from ptrace_exit() - * when the tracing task dies. - * - * Called with write_lock(&tasklist_lock) held. - */ -#define arch_ptrace_untrace(task) do { } while (0) -#endif - extern int task_current_syscall(struct task_struct *target, long *callno, unsigned long args[6], unsigned int maxargs, unsigned long *sp, unsigned long *pc); diff --git a/include/linux/sched.h b/include/linux/sched.h index dad7f668ebf..e0447c64af6 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -99,7 +99,6 @@ struct futex_pi_state; struct robust_list_head; struct bio_list; struct fs_struct; -struct bts_context; struct perf_event_context; /* @@ -1272,12 +1271,6 @@ struct task_struct { struct list_head ptraced; struct list_head ptrace_entry; - /* - * This is the tracer handle for the ptrace BTS extension. - * This field actually belongs to the ptracer task. - */ - struct bts_context *bts; - /* PID/PID hash table linkage. */ struct pid_link pids[PIDTYPE_MAX]; struct list_head thread_group; @@ -2123,10 +2116,8 @@ extern void set_task_comm(struct task_struct *tsk, char *from); extern char *get_task_comm(char *to, struct task_struct *tsk); #ifdef CONFIG_SMP -extern void wait_task_context_switch(struct task_struct *p); extern unsigned long wait_task_inactive(struct task_struct *, long match_state); #else -static inline void wait_task_context_switch(struct task_struct *p) {} static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state) { diff --git a/kernel/fork.c b/kernel/fork.c index 4799c5f0e6d..d67f1dbfbe0 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1108,9 +1108,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->memcg_batch.do_batch = 0; p->memcg_batch.memcg = NULL; #endif - - p->bts = NULL; - p->stack_start = stack_start; /* Perform scheduler related setup. Assign this task to a CPU. */ diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 42ad8ae729a..9fb51237b18 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -76,7 +76,6 @@ void __ptrace_unlink(struct task_struct *child) child->parent = child->real_parent; list_del_init(&child->ptrace_entry); - arch_ptrace_untrace(child); if (task_is_traced(child)) ptrace_untrace(child); } diff --git a/kernel/sched.c b/kernel/sched.c index 9ab3cd7858d..117b7cad31b 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2076,49 +2076,6 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) return 1; } -/* - * wait_task_context_switch - wait for a thread to complete at least one - * context switch. - * - * @p must not be current. - */ -void wait_task_context_switch(struct task_struct *p) -{ - unsigned long nvcsw, nivcsw, flags; - int running; - struct rq *rq; - - nvcsw = p->nvcsw; - nivcsw = p->nivcsw; - for (;;) { - /* - * The runqueue is assigned before the actual context - * switch. We need to take the runqueue lock. - * - * We could check initially without the lock but it is - * very likely that we need to take the lock in every - * iteration. - */ - rq = task_rq_lock(p, &flags); - running = task_running(rq, p); - task_rq_unlock(rq, &flags); - - if (likely(!running)) - break; - /* - * The switch count is incremented before the actual - * context switch. We thus wait for two switches to be - * sure at least one completed. - */ - if ((p->nvcsw - nvcsw) > 1) - break; - if ((p->nivcsw - nivcsw) > 1) - break; - - cpu_relax(); - } -} - /* * wait_task_inactive - wait for a thread to unschedule. * diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 13e13d428cd..8b1797c4545 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -44,9 +44,6 @@ config HAVE_FTRACE_MCOUNT_RECORD help See Documentation/trace/ftrace-design.txt -config HAVE_HW_BRANCH_TRACER - bool - config HAVE_SYSCALL_TRACEPOINTS bool help @@ -374,14 +371,6 @@ config STACK_TRACER Say N if unsure. -config HW_BRANCH_TRACER - depends on HAVE_HW_BRANCH_TRACER - bool "Trace hw branches" - select GENERIC_TRACER - help - This tracer records all branches on the system in a circular - buffer, giving access to the last N branches for each cpu. - config KMEMTRACE bool "Trace SLAB allocations" select GENERIC_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 78edc649003..ffb1a5b0550 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -41,7 +41,6 @@ obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o obj-$(CONFIG_BOOT_TRACER) += trace_boot.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o -obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o obj-$(CONFIG_KMEMTRACE) += kmemtrace.o obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 2825ef2c0b1..bec2c973ff0 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -34,7 +34,6 @@ enum trace_type { TRACE_GRAPH_RET, TRACE_GRAPH_ENT, TRACE_USER_STACK, - TRACE_HW_BRANCHES, TRACE_KMEM_ALLOC, TRACE_KMEM_FREE, TRACE_BLK, @@ -229,7 +228,6 @@ extern void __ftrace_bad_type(void); TRACE_GRAPH_ENT); \ IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ TRACE_GRAPH_RET); \ - IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\ IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry, \ TRACE_KMEM_ALLOC); \ IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \ @@ -467,8 +465,6 @@ extern int trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr); -extern int trace_selftest_startup_hw_branches(struct tracer *trace, - struct trace_array *tr); extern int trace_selftest_startup_ksym(struct tracer *trace, struct trace_array *tr); #endif /* CONFIG_FTRACE_STARTUP_TEST */ diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index c16a08f399d..dc008c1240d 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -318,18 +318,6 @@ FTRACE_ENTRY(branch, trace_branch, __entry->func, __entry->file, __entry->correct) ); -FTRACE_ENTRY(hw_branch, hw_branch_entry, - - TRACE_HW_BRANCHES, - - F_STRUCT( - __field( u64, from ) - __field( u64, to ) - ), - - F_printk("from: %llx to: %llx", __entry->from, __entry->to) -); - FTRACE_ENTRY(kmem_alloc, kmemtrace_alloc_entry, TRACE_KMEM_ALLOC, diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c deleted file mode 100644 index 7b97000745f..00000000000 --- a/kernel/trace/trace_hw_branches.c +++ /dev/null @@ -1,312 +0,0 @@ -/* - * h/w branch tracer for x86 based on BTS - * - * Copyright (C) 2008-2009 Intel Corporation. - * Markus Metzger , 2008-2009 - */ -#include -#include -#include -#include -#include -#include -#include - -#include - -#include "trace_output.h" -#include "trace.h" - - -#define BTS_BUFFER_SIZE (1 << 13) - -static DEFINE_PER_CPU(struct bts_tracer *, hwb_tracer); -static DEFINE_PER_CPU(unsigned char[BTS_BUFFER_SIZE], hwb_buffer); - -#define this_tracer per_cpu(hwb_tracer, smp_processor_id()) - -static int trace_hw_branches_enabled __read_mostly; -static int trace_hw_branches_suspended __read_mostly; -static struct trace_array *hw_branch_trace __read_mostly; - - -static void bts_trace_init_cpu(int cpu) -{ - per_cpu(hwb_tracer, cpu) = - ds_request_bts_cpu(cpu, per_cpu(hwb_buffer, cpu), - BTS_BUFFER_SIZE, NULL, (size_t)-1, - BTS_KERNEL); - - if (IS_ERR(per_cpu(hwb_tracer, cpu))) - per_cpu(hwb_tracer, cpu) = NULL; -} - -static int bts_trace_init(struct trace_array *tr) -{ - int cpu; - - hw_branch_trace = tr; - trace_hw_branches_enabled = 0; - - get_online_cpus(); - for_each_online_cpu(cpu) { - bts_trace_init_cpu(cpu); - - if (likely(per_cpu(hwb_tracer, cpu))) - trace_hw_branches_enabled = 1; - } - trace_hw_branches_suspended = 0; - put_online_cpus(); - - /* If we could not enable tracing on a single cpu, we fail. */ - return trace_hw_branches_enabled ? 0 : -EOPNOTSUPP; -} - -static void bts_trace_reset(struct trace_array *tr) -{ - int cpu; - - get_online_cpus(); - for_each_online_cpu(cpu) { - if (likely(per_cpu(hwb_tracer, cpu))) { - ds_release_bts(per_cpu(hwb_tracer, cpu)); - per_cpu(hwb_tracer, cpu) = NULL; - } - } - trace_hw_branches_enabled = 0; - trace_hw_branches_suspended = 0; - put_online_cpus(); -} - -static void bts_trace_start(struct trace_array *tr) -{ - int cpu; - - get_online_cpus(); - for_each_online_cpu(cpu) - if (likely(per_cpu(hwb_tracer, cpu))) - ds_resume_bts(per_cpu(hwb_tracer, cpu)); - trace_hw_branches_suspended = 0; - put_online_cpus(); -} - -static void bts_trace_stop(struct trace_array *tr) -{ - int cpu; - - get_online_cpus(); - for_each_online_cpu(cpu) - if (likely(per_cpu(hwb_tracer, cpu))) - ds_suspend_bts(per_cpu(hwb_tracer, cpu)); - trace_hw_branches_suspended = 1; - put_online_cpus(); -} - -static int __cpuinit bts_hotcpu_handler(struct notifier_block *nfb, - unsigned long action, void *hcpu) -{ - int cpu = (long)hcpu; - - switch (action) { - case CPU_ONLINE: - case CPU_DOWN_FAILED: - /* The notification is sent with interrupts enabled. */ - if (trace_hw_branches_enabled) { - bts_trace_init_cpu(cpu); - - if (trace_hw_branches_suspended && - likely(per_cpu(hwb_tracer, cpu))) - ds_suspend_bts(per_cpu(hwb_tracer, cpu)); - } - break; - - case CPU_DOWN_PREPARE: - /* The notification is sent with interrupts enabled. */ - if (likely(per_cpu(hwb_tracer, cpu))) { - ds_release_bts(per_cpu(hwb_tracer, cpu)); - per_cpu(hwb_tracer, cpu) = NULL; - } - } - - return NOTIFY_DONE; -} - -static struct notifier_block bts_hotcpu_notifier __cpuinitdata = { - .notifier_call = bts_hotcpu_handler -}; - -static void bts_trace_print_header(struct seq_file *m) -{ - seq_puts(m, "# CPU# TO <- FROM\n"); -} - -static enum print_line_t bts_trace_print_line(struct trace_iterator *iter) -{ - unsigned long symflags = TRACE_ITER_SYM_OFFSET; - struct trace_entry *entry = iter->ent; - struct trace_seq *seq = &iter->seq; - struct hw_branch_entry *it; - - trace_assign_type(it, entry); - - if (entry->type == TRACE_HW_BRANCHES) { - if (trace_seq_printf(seq, "%4d ", iter->cpu) && - seq_print_ip_sym(seq, it->to, symflags) && - trace_seq_printf(seq, "\t <- ") && - seq_print_ip_sym(seq, it->from, symflags) && - trace_seq_printf(seq, "\n")) - return TRACE_TYPE_HANDLED; - return TRACE_TYPE_PARTIAL_LINE; - } - return TRACE_TYPE_UNHANDLED; -} - -void trace_hw_branch(u64 from, u64 to) -{ - struct ftrace_event_call *call = &event_hw_branch; - struct trace_array *tr = hw_branch_trace; - struct ring_buffer_event *event; - struct ring_buffer *buf; - struct hw_branch_entry *entry; - unsigned long irq1; - int cpu; - - if (unlikely(!tr)) - return; - - if (unlikely(!trace_hw_branches_enabled)) - return; - - local_irq_save(irq1); - cpu = raw_smp_processor_id(); - if (atomic_inc_return(&tr->data[cpu]->disabled) != 1) - goto out; - - buf = tr->buffer; - event = trace_buffer_lock_reserve(buf, TRACE_HW_BRANCHES, - sizeof(*entry), 0, 0); - if (!event) - goto out; - entry = ring_buffer_event_data(event); - tracing_generic_entry_update(&entry->ent, 0, from); - entry->ent.type = TRACE_HW_BRANCHES; - entry->from = from; - entry->to = to; - if (!filter_check_discard(call, entry, buf, event)) - trace_buffer_unlock_commit(buf, event, 0, 0); - - out: - atomic_dec(&tr->data[cpu]->disabled); - local_irq_restore(irq1); -} - -static void trace_bts_at(const struct bts_trace *trace, void *at) -{ - struct bts_struct bts; - int err = 0; - - WARN_ON_ONCE(!trace->read); - if (!trace->read) - return; - - err = trace->read(this_tracer, at, &bts); - if (err < 0) - return; - - switch (bts.qualifier) { - case BTS_BRANCH: - trace_hw_branch(bts.variant.lbr.from, bts.variant.lbr.to); - break; - } -} - -/* - * Collect the trace on the current cpu and write it into the ftrace buffer. - * - * pre: tracing must be suspended on the current cpu - */ -static void trace_bts_cpu(void *arg) -{ - struct trace_array *tr = (struct trace_array *)arg; - const struct bts_trace *trace; - unsigned char *at; - - if (unlikely(!tr)) - return; - - if (unlikely(atomic_read(&tr->data[raw_smp_processor_id()]->disabled))) - return; - - if (unlikely(!this_tracer)) - return; - - trace = ds_read_bts(this_tracer); - if (!trace) - return; - - for (at = trace->ds.top; (void *)at < trace->ds.end; - at += trace->ds.size) - trace_bts_at(trace, at); - - for (at = trace->ds.begin; (void *)at < trace->ds.top; - at += trace->ds.size) - trace_bts_at(trace, at); -} - -static void trace_bts_prepare(struct trace_iterator *iter) -{ - int cpu; - - get_online_cpus(); - for_each_online_cpu(cpu) - if (likely(per_cpu(hwb_tracer, cpu))) - ds_suspend_bts(per_cpu(hwb_tracer, cpu)); - /* - * We need to collect the trace on the respective cpu since ftrace - * implicitly adds the record for the current cpu. - * Once that is more flexible, we could collect the data from any cpu. - */ - on_each_cpu(trace_bts_cpu, iter->tr, 1); - - for_each_online_cpu(cpu) - if (likely(per_cpu(hwb_tracer, cpu))) - ds_resume_bts(per_cpu(hwb_tracer, cpu)); - put_online_cpus(); -} - -static void trace_bts_close(struct trace_iterator *iter) -{ - tracing_reset_online_cpus(iter->tr); -} - -void trace_hw_branch_oops(void) -{ - if (this_tracer) { - ds_suspend_bts_noirq(this_tracer); - trace_bts_cpu(hw_branch_trace); - ds_resume_bts_noirq(this_tracer); - } -} - -struct tracer bts_tracer __read_mostly = -{ - .name = "hw-branch-tracer", - .init = bts_trace_init, - .reset = bts_trace_reset, - .print_header = bts_trace_print_header, - .print_line = bts_trace_print_line, - .start = bts_trace_start, - .stop = bts_trace_stop, - .open = trace_bts_prepare, - .close = trace_bts_close, -#ifdef CONFIG_FTRACE_SELFTEST - .selftest = trace_selftest_startup_hw_branches, -#endif /* CONFIG_FTRACE_SELFTEST */ -}; - -__init static int init_bts_trace(void) -{ - register_hotcpu_notifier(&bts_hotcpu_notifier); - return register_tracer(&bts_tracer); -} -device_initcall(init_bts_trace); diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 280fea470d6..a7084e7c042 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -16,7 +16,6 @@ static inline int trace_valid_entry(struct trace_entry *entry) case TRACE_BRANCH: case TRACE_GRAPH_ENT: case TRACE_GRAPH_RET: - case TRACE_HW_BRANCHES: case TRACE_KSYM: return 1; } @@ -754,62 +753,6 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr) } #endif /* CONFIG_BRANCH_TRACER */ -#ifdef CONFIG_HW_BRANCH_TRACER -int -trace_selftest_startup_hw_branches(struct tracer *trace, - struct trace_array *tr) -{ - struct trace_iterator *iter; - struct tracer tracer; - unsigned long count; - int ret; - - if (!trace->open) { - printk(KERN_CONT "missing open function..."); - return -1; - } - - ret = tracer_init(trace, tr); - if (ret) { - warn_failed_init_tracer(trace, ret); - return ret; - } - - /* - * The hw-branch tracer needs to collect the trace from the various - * cpu trace buffers - before tracing is stopped. - */ - iter = kzalloc(sizeof(*iter), GFP_KERNEL); - if (!iter) - return -ENOMEM; - - memcpy(&tracer, trace, sizeof(tracer)); - - iter->trace = &tracer; - iter->tr = tr; - iter->pos = -1; - mutex_init(&iter->mutex); - - trace->open(iter); - - mutex_destroy(&iter->mutex); - kfree(iter); - - tracing_stop(); - - ret = trace_test_buffer(tr, &count); - trace->reset(tr); - tracing_start(); - - if (!ret && !count) { - printk(KERN_CONT "no entries found.."); - ret = -1; - } - - return ret; -} -#endif /* CONFIG_HW_BRANCH_TRACER */ - #ifdef CONFIG_KSYM_TRACER static int ksym_selftest_dummy; diff --git a/mm/mlock.c b/mm/mlock.c index 8f4e2dfceec..3f82720e051 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -607,44 +607,3 @@ void user_shm_unlock(size_t size, struct user_struct *user) spin_unlock(&shmlock_user_lock); free_uid(user); } - -int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim, - size_t size) -{ - unsigned long lim, vm, pgsz; - int error = -ENOMEM; - - pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT; - - down_write(&mm->mmap_sem); - - lim = ACCESS_ONCE(rlim[RLIMIT_AS].rlim_cur) >> PAGE_SHIFT; - vm = mm->total_vm + pgsz; - if (lim < vm) - goto out; - - lim = ACCESS_ONCE(rlim[RLIMIT_MEMLOCK].rlim_cur) >> PAGE_SHIFT; - vm = mm->locked_vm + pgsz; - if (lim < vm) - goto out; - - mm->total_vm += pgsz; - mm->locked_vm += pgsz; - - error = 0; - out: - up_write(&mm->mmap_sem); - return error; -} - -void refund_locked_memory(struct mm_struct *mm, size_t size) -{ - unsigned long pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT; - - down_write(&mm->mmap_sem); - - mm->total_vm -= pgsz; - mm->locked_vm -= pgsz; - - up_write(&mm->mmap_sem); -} -- cgit v1.2.3-70-g09d2 From 4bdde044dc36ac7b01f7502394d52619af9d1927 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 24 Mar 2010 10:58:05 +0800 Subject: tracing: Convert some signal events to DEFINE_TRACE Use DECLARE_EVENT_CLASS to remove duplicate code: text data bss dec hex filename 23639 6084 8 29731 7423 kernel/signal.o.orig 22727 6084 8 28819 7093 kernel/signal.o 2 events are converted: signal_queue_overflow: signal_overflow_fail, signal_lose_info No functional change. Acked-by: Masami Hiramatsu Signed-off-by: Li Zefan LKML-Reference: <4BA97FBD.8070703@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- include/trace/events/signal.h | 52 ++++++++++++++++++------------------------- 1 file changed, 22 insertions(+), 30 deletions(-) (limited to 'include') diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h index a510b75ac30..814566c99d2 100644 --- a/include/trace/events/signal.h +++ b/include/trace/events/signal.h @@ -100,18 +100,7 @@ TRACE_EVENT(signal_deliver, __entry->sa_handler, __entry->sa_flags) ); -/** - * signal_overflow_fail - called when signal queue is overflow - * @sig: signal number - * @group: signal to process group or not (bool) - * @info: pointer to struct siginfo - * - * Kernel fails to generate 'sig' signal with 'info' siginfo, because - * siginfo queue is overflow, and the signal is dropped. - * 'group' is not 0 if the signal will be sent to a process group. - * 'sig' is always one of RT signals. - */ -TRACE_EVENT(signal_overflow_fail, +DECLARE_EVENT_CLASS(signal_queue_overflow, TP_PROTO(int sig, int group, struct siginfo *info), @@ -134,6 +123,24 @@ TRACE_EVENT(signal_overflow_fail, __entry->sig, __entry->group, __entry->errno, __entry->code) ); +/** + * signal_overflow_fail - called when signal queue is overflow + * @sig: signal number + * @group: signal to process group or not (bool) + * @info: pointer to struct siginfo + * + * Kernel fails to generate 'sig' signal with 'info' siginfo, because + * siginfo queue is overflow, and the signal is dropped. + * 'group' is not 0 if the signal will be sent to a process group. + * 'sig' is always one of RT signals. + */ +DEFINE_EVENT(signal_queue_overflow, signal_overflow_fail, + + TP_PROTO(int sig, int group, struct siginfo *info), + + TP_ARGS(sig, group, info) +); + /** * signal_lose_info - called when siginfo is lost * @sig: signal number @@ -145,28 +152,13 @@ TRACE_EVENT(signal_overflow_fail, * 'group' is not 0 if the signal will be sent to a process group. * 'sig' is always one of non-RT signals. */ -TRACE_EVENT(signal_lose_info, +DEFINE_EVENT(signal_queue_overflow, signal_lose_info, TP_PROTO(int sig, int group, struct siginfo *info), - TP_ARGS(sig, group, info), - - TP_STRUCT__entry( - __field( int, sig ) - __field( int, group ) - __field( int, errno ) - __field( int, code ) - ), - - TP_fast_assign( - __entry->sig = sig; - __entry->group = group; - TP_STORE_SIGINFO(__entry, info); - ), - - TP_printk("sig=%d group=%d errno=%d code=%d", - __entry->sig, __entry->group, __entry->errno, __entry->code) + TP_ARGS(sig, group, info) ); + #endif /* _TRACE_SIGNAL_H */ /* This part must be outside protection */ -- cgit v1.2.3-70-g09d2 From 50354a8a28d0c91695a2d6d25b5a821bfe557a07 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 24 Mar 2010 10:58:24 +0800 Subject: tracing: Update comments Make some comments consistent with the code. Signed-off-by: Li Zefan LKML-Reference: <4BA97FD0.7090202@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- include/trace/ftrace.h | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-) (limited to 'include') diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index ea6f9d4a20e..75dd7787fb3 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -154,9 +154,11 @@ * * field = (typeof(field))entry; * - * p = get_cpu_var(ftrace_event_seq); + * p = &get_cpu_var(ftrace_event_seq); * trace_seq_init(p); - * ret = trace_seq_printf(s, "\n"); + * ret = trace_seq_printf(s, "%s: ", ); + * if (ret) + * ret = trace_seq_printf(s, "\n"); * put_cpu(); * if (!ret) * return TRACE_TYPE_PARTIAL_LINE; @@ -450,38 +452,38 @@ perf_trace_disable_##name(struct ftrace_event_call *unused) \ * * static void ftrace_raw_event_(proto) * { + * struct ftrace_data_offsets_ __maybe_unused __data_offsets; * struct ring_buffer_event *event; * struct ftrace_raw_ *entry; <-- defined in stage 1 * struct ring_buffer *buffer; * unsigned long irq_flags; + * int __data_size; * int pc; * * local_save_flags(irq_flags); * pc = preempt_count(); * + * __data_size = ftrace_get_offsets_(&__data_offsets, args); + * * event = trace_current_buffer_lock_reserve(&buffer, * event_.id, - * sizeof(struct ftrace_raw_), + * sizeof(*entry) + __data_size, * irq_flags, pc); * if (!event) * return; * entry = ring_buffer_event_data(event); * - * ; <-- Here we assign the entries by the __field and - * __array macros. + * { ; } <-- Here we assign the entries by the __field and + * __array macros. * - * trace_current_buffer_unlock_commit(buffer, event, irq_flags, pc); + * if (!filter_current_check_discard(buffer, event_call, entry, event)) + * trace_current_buffer_unlock_commit(buffer, + * event, irq_flags, pc); * } * * static int ftrace_raw_reg_event_(struct ftrace_event_call *unused) * { - * int ret; - * - * ret = register_trace_(ftrace_raw_event_); - * if (!ret) - * pr_info("event trace: Could not activate trace point " - * "probe to "); - * return ret; + * return register_trace_(ftrace_raw_event_); * } * * static void ftrace_unreg_event_(struct ftrace_event_call *unused) @@ -493,6 +495,8 @@ perf_trace_disable_##name(struct ftrace_event_call *unused) \ * .trace = ftrace_raw_output_, <-- stage 2 * }; * + * static const char print_fmt_[] = ; + * * static struct ftrace_event_call __used * __attribute__((__aligned__(4))) * __attribute__((section("_ftrace_events"))) event_ = { @@ -501,6 +505,8 @@ perf_trace_disable_##name(struct ftrace_event_call *unused) \ * .raw_init = trace_event_raw_init, * .regfunc = ftrace_reg_event_, * .unregfunc = ftrace_unreg_event_, + * .print_fmt = print_fmt_, + * .define_fields = ftrace_define_fields_, * } * */ @@ -569,7 +575,6 @@ ftrace_raw_event_id_##call(struct ftrace_event_call *event_call, \ return; \ entry = ring_buffer_event_data(event); \ \ - \ tstruct \ \ { assign; } \ -- cgit v1.2.3-70-g09d2 From ae832d1e03ac9bf09fb8a07fb37908ab40c7cd0e Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 24 Mar 2010 10:57:43 +0800 Subject: tracing: Remove side effect from module tracepoints that caused a GPF Remove the @refcnt argument, because it has side-effects, and arguments with side-effects are not skipped by the jump over disabled instrumentation and are executed even when the tracepoint is disabled. This was also causing a GPF as found by Randy Dunlap: Subject: 2.6.33 GP fault only when built with tracing LKML-Reference: <4BA2B69D.3000309@oracle.com> Note, the current 2.6.34-rc has a fix for the actual cause of the GPF, but this fixes one of its triggers. Tested-by: Randy Dunlap Acked-by: Mathieu Desnoyers Signed-off-by: Li Zefan LKML-Reference: <4BA97FA7.6040406@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- include/linux/module.h | 6 ++---- include/trace/events/module.h | 14 +++++++------- kernel/module.c | 3 +-- 3 files changed, 10 insertions(+), 13 deletions(-) (limited to 'include') diff --git a/include/linux/module.h b/include/linux/module.h index 5e869ffd34a..393ec39b580 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -460,8 +460,7 @@ static inline void __module_get(struct module *module) if (module) { preempt_disable(); __this_cpu_inc(module->refptr->count); - trace_module_get(module, _THIS_IP_, - __this_cpu_read(module->refptr->count)); + trace_module_get(module, _THIS_IP_); preempt_enable(); } } @@ -475,8 +474,7 @@ static inline int try_module_get(struct module *module) if (likely(module_is_live(module))) { __this_cpu_inc(module->refptr->count); - trace_module_get(module, _THIS_IP_, - __this_cpu_read(module->refptr->count)); + trace_module_get(module, _THIS_IP_); } else ret = 0; diff --git a/include/trace/events/module.h b/include/trace/events/module.h index 4b0f48ba16a..a585f8135bd 100644 --- a/include/trace/events/module.h +++ b/include/trace/events/module.h @@ -53,9 +53,9 @@ TRACE_EVENT(module_free, DECLARE_EVENT_CLASS(module_refcnt, - TP_PROTO(struct module *mod, unsigned long ip, int refcnt), + TP_PROTO(struct module *mod, unsigned long ip), - TP_ARGS(mod, ip, refcnt), + TP_ARGS(mod, ip), TP_STRUCT__entry( __field( unsigned long, ip ) @@ -65,7 +65,7 @@ DECLARE_EVENT_CLASS(module_refcnt, TP_fast_assign( __entry->ip = ip; - __entry->refcnt = refcnt; + __entry->refcnt = __this_cpu_read(mod->refptr->count); __assign_str(name, mod->name); ), @@ -75,16 +75,16 @@ DECLARE_EVENT_CLASS(module_refcnt, DEFINE_EVENT(module_refcnt, module_get, - TP_PROTO(struct module *mod, unsigned long ip, int refcnt), + TP_PROTO(struct module *mod, unsigned long ip), - TP_ARGS(mod, ip, refcnt) + TP_ARGS(mod, ip) ); DEFINE_EVENT(module_refcnt, module_put, - TP_PROTO(struct module *mod, unsigned long ip, int refcnt), + TP_PROTO(struct module *mod, unsigned long ip), - TP_ARGS(mod, ip, refcnt) + TP_ARGS(mod, ip) ); TRACE_EVENT(module_request, diff --git a/kernel/module.c b/kernel/module.c index c968d3606dc..21591ad921f 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -800,8 +800,7 @@ void module_put(struct module *module) preempt_disable(); __this_cpu_dec(module->refptr->count); - trace_module_put(module, _RET_IP_, - __this_cpu_read(module->refptr->count)); + trace_module_put(module, _RET_IP_); /* Maybe they're waiting for us to drop reference? */ if (unlikely(!module_is_live(module))) wake_up_process(module->waiter); -- cgit v1.2.3-70-g09d2 From eb0c53771fb2f5f66b0edb3ebce33be4bbf1c285 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 29 Mar 2010 14:25:18 -0400 Subject: tracing: Fix compile error in module tracepoints when MODULE_UNLOAD not set If modules are configured in the build but unloading of modules is not, then the refcnt is not defined. Place the get/put module tracepoints under CONFIG_MODULE_UNLOAD since it references this field in the module structure. As a side-effect, this patch also reduces the code when MODULE_UNLOAD is not set, because these unused tracepoints are not created. Signed-off-by: Steven Rostedt --- include/trace/events/module.h | 4 ++++ kernel/module.c | 5 +++-- 2 files changed, 7 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/trace/events/module.h b/include/trace/events/module.h index a585f8135bd..f07b44a2b24 100644 --- a/include/trace/events/module.h +++ b/include/trace/events/module.h @@ -51,6 +51,9 @@ TRACE_EVENT(module_free, TP_printk("%s", __get_str(name)) ); +#ifdef CONFIG_MODULE_UNLOAD +/* trace_module_get/put are only used if CONFIG_MODULE_UNLOAD is defined */ + DECLARE_EVENT_CLASS(module_refcnt, TP_PROTO(struct module *mod, unsigned long ip), @@ -86,6 +89,7 @@ DEFINE_EVENT(module_refcnt, module_put, TP_ARGS(mod, ip) ); +#endif /* CONFIG_MODULE_UNLOAD */ TRACE_EVENT(module_request, diff --git a/kernel/module.c b/kernel/module.c index 21591ad921f..d9e237926b6 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -59,8 +59,6 @@ #define CREATE_TRACE_POINTS #include -EXPORT_TRACEPOINT_SYMBOL(module_get); - #if 0 #define DEBUGP printk #else @@ -467,6 +465,9 @@ MODINFO_ATTR(srcversion); static char last_unloaded_module[MODULE_NAME_LEN+1]; #ifdef CONFIG_MODULE_UNLOAD + +EXPORT_TRACEPOINT_SYMBOL(module_get); + /* Init the unload section of the module. */ static void module_unload_init(struct module *mod) { -- cgit v1.2.3-70-g09d2 From 66a8cb95ed04025664d1db4e952155ee1dccd048 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 31 Mar 2010 13:21:56 -0400 Subject: ring-buffer: Add place holder recording of dropped events Currently, when the ring buffer drops events, it does not record the fact that it did so. It does inform the writer that the event was dropped by returning a NULL event, but it does not put in any place holder where the event was dropped. This is not a trivial thing to add because the ring buffer mostly runs in overwrite (flight recorder) mode. That is, when the ring buffer is full, new data will overwrite old data. In a produce/consumer mode, where new data is simply dropped when the ring buffer is full, it is trivial to add the placeholder for dropped events. When there's more room to write new data, then a special event can be added to notify the reader about the dropped events. But in overwrite mode, any new write can overwrite events. A place holder can not be inserted into the ring buffer since there never may be room. A reader could also come in at anytime and miss the placeholder. Luckily, the way the ring buffer works, the read side can find out if events were lost or not, and how many events. Everytime a write takes place, if it overwrites the header page (the next read) it updates a "overrun" variable that keeps track of the number of lost events. When a reader swaps out a page from the ring buffer, it can record this number, perfom the swap, and then check to see if the number changed, and take the diff if it has, which would be the number of events dropped. This can be stored by the reader and returned to callers of the reader. Since the reader page swap will fail if the writer moved the head page since the time the reader page set up the swap, this gives room to record the overruns without worrying about races. If the reader sets up the pages, records the overrun, than performs the swap, if the swap succeeds, then the overrun variable has not been updated since the setup before the swap. For binary readers of the ring buffer, a flag is set in the header of each sub page (sub buffer) of the ring buffer. This flag is embedded in the size field of the data on the sub buffer, in the 31st bit (the size can be 32 or 64 bits depending on the architecture), but only 27 bits needs to be used for the actual size (less actually). We could add a new field in the sub buffer header to also record the number of events dropped since the last read, but this will change the format of the binary ring buffer a bit too much. Perhaps this change can be made if the information on the number of events dropped is considered important enough. Note, the notification of dropped events is only used by consuming reads or peeking at the ring buffer. Iterating over the ring buffer does not keep this information because the necessary data is only available when a page swap is made, and the iterator does not swap out pages. Cc: Robert Richter Cc: Andi Kleen Cc: Li Zefan Cc: Arnaldo Carvalho de Melo Cc: "Luis Claudio R. Goncalves" Cc: Frederic Weisbecker Signed-off-by: Steven Rostedt --- drivers/oprofile/cpu_buffer.c | 4 +- include/linux/ring_buffer.h | 6 ++- kernel/trace/ring_buffer.c | 72 +++++++++++++++++++++++++++++++++--- kernel/trace/ring_buffer_benchmark.c | 2 +- kernel/trace/trace.c | 4 +- kernel/trace/trace_functions_graph.c | 5 ++- kernel/trace/trace_selftest.c | 2 +- 7 files changed, 79 insertions(+), 16 deletions(-) (limited to 'include') diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c index 166b67ea622..7581dbe456d 100644 --- a/drivers/oprofile/cpu_buffer.c +++ b/drivers/oprofile/cpu_buffer.c @@ -186,14 +186,14 @@ int op_cpu_buffer_write_commit(struct op_entry *entry) struct op_sample *op_cpu_buffer_read_entry(struct op_entry *entry, int cpu) { struct ring_buffer_event *e; - e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL); + e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL, NULL); if (e) goto event; if (ring_buffer_swap_cpu(op_ring_buffer_read, op_ring_buffer_write, cpu)) return NULL; - e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL); + e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL, NULL); if (e) goto event; return NULL; diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index 5fcc31ed577..c8297761e41 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -120,9 +120,11 @@ int ring_buffer_write(struct ring_buffer *buffer, unsigned long length, void *data); struct ring_buffer_event * -ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts); +ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts, + unsigned long *lost_events); struct ring_buffer_event * -ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts); +ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts, + unsigned long *lost_events); struct ring_buffer_iter * ring_buffer_read_start(struct ring_buffer *buffer, int cpu); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index d1187ef20ca..8295650444c 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -318,6 +318,9 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data); #define TS_MASK ((1ULL << TS_SHIFT) - 1) #define TS_DELTA_TEST (~TS_MASK) +/* Flag when events were overwritten */ +#define RB_MISSED_EVENTS (1 << 31) + struct buffer_data_page { u64 time_stamp; /* page time stamp */ local_t commit; /* write committed index */ @@ -416,6 +419,12 @@ int ring_buffer_print_page_header(struct trace_seq *s) (unsigned int)sizeof(field.commit), (unsigned int)is_signed_type(long)); + ret = trace_seq_printf(s, "\tfield: int overwrite;\t" + "offset:%u;\tsize:%u;\tsigned:%u;\n", + (unsigned int)offsetof(typeof(field), commit), + 1, + (unsigned int)is_signed_type(long)); + ret = trace_seq_printf(s, "\tfield: char data;\t" "offset:%u;\tsize:%u;\tsigned:%u;\n", (unsigned int)offsetof(typeof(field), data), @@ -439,6 +448,8 @@ struct ring_buffer_per_cpu { struct buffer_page *tail_page; /* write to tail */ struct buffer_page *commit_page; /* committed pages */ struct buffer_page *reader_page; + unsigned long lost_events; + unsigned long last_overrun; local_t commit_overrun; local_t overrun; local_t entries; @@ -2835,6 +2846,7 @@ static struct buffer_page * rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) { struct buffer_page *reader = NULL; + unsigned long overwrite; unsigned long flags; int nr_loops = 0; int ret; @@ -2895,6 +2907,18 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) /* The reader page will be pointing to the new head */ rb_set_list_to_head(cpu_buffer, &cpu_buffer->reader_page->list); + /* + * We want to make sure we read the overruns after we set up our + * pointers to the next object. The writer side does a + * cmpxchg to cross pages which acts as the mb on the writer + * side. Note, the reader will constantly fail the swap + * while the writer is updating the pointers, so this + * guarantees that the overwrite recorded here is the one we + * want to compare with the last_overrun. + */ + smp_mb(); + overwrite = local_read(&(cpu_buffer->overrun)); + /* * Here's the tricky part. * @@ -2926,6 +2950,11 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) cpu_buffer->reader_page = reader; rb_reset_reader_page(cpu_buffer); + if (overwrite != cpu_buffer->last_overrun) { + cpu_buffer->lost_events = overwrite - cpu_buffer->last_overrun; + cpu_buffer->last_overrun = overwrite; + } + goto again; out: @@ -3002,8 +3031,14 @@ static void rb_advance_iter(struct ring_buffer_iter *iter) rb_advance_iter(iter); } +static int rb_lost_events(struct ring_buffer_per_cpu *cpu_buffer) +{ + return cpu_buffer->lost_events; +} + static struct ring_buffer_event * -rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts) +rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts, + unsigned long *lost_events) { struct ring_buffer_event *event; struct buffer_page *reader; @@ -3055,6 +3090,8 @@ rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts) ring_buffer_normalize_time_stamp(cpu_buffer->buffer, cpu_buffer->cpu, ts); } + if (lost_events) + *lost_events = rb_lost_events(cpu_buffer); return event; default: @@ -3165,12 +3202,14 @@ static inline int rb_ok_to_lock(void) * @buffer: The ring buffer to read * @cpu: The cpu to peak at * @ts: The timestamp counter of this event. + * @lost_events: a variable to store if events were lost (may be NULL) * * This will return the event that will be read next, but does * not consume the data. */ struct ring_buffer_event * -ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) +ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts, + unsigned long *lost_events) { struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu]; struct ring_buffer_event *event; @@ -3185,7 +3224,7 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) local_irq_save(flags); if (dolock) spin_lock(&cpu_buffer->reader_lock); - event = rb_buffer_peek(cpu_buffer, ts); + event = rb_buffer_peek(cpu_buffer, ts, lost_events); if (event && event->type_len == RINGBUF_TYPE_PADDING) rb_advance_reader(cpu_buffer); if (dolock) @@ -3227,13 +3266,17 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts) /** * ring_buffer_consume - return an event and consume it * @buffer: The ring buffer to get the next event from + * @cpu: the cpu to read the buffer from + * @ts: a variable to store the timestamp (may be NULL) + * @lost_events: a variable to store if events were lost (may be NULL) * * Returns the next event in the ring buffer, and that event is consumed. * Meaning, that sequential reads will keep returning a different event, * and eventually empty the ring buffer if the producer is slower. */ struct ring_buffer_event * -ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts) +ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts, + unsigned long *lost_events) { struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event = NULL; @@ -3254,9 +3297,11 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts) if (dolock) spin_lock(&cpu_buffer->reader_lock); - event = rb_buffer_peek(cpu_buffer, ts); - if (event) + event = rb_buffer_peek(cpu_buffer, ts, lost_events); + if (event) { + cpu_buffer->lost_events = 0; rb_advance_reader(cpu_buffer); + } if (dolock) spin_unlock(&cpu_buffer->reader_lock); @@ -3405,6 +3450,9 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer) cpu_buffer->write_stamp = 0; cpu_buffer->read_stamp = 0; + cpu_buffer->lost_events = 0; + cpu_buffer->last_overrun = 0; + rb_head_page_activate(cpu_buffer); } @@ -3684,6 +3732,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer, unsigned int commit; unsigned int read; u64 save_timestamp; + int missed_events = 0; int ret = -1; if (!cpumask_test_cpu(cpu, buffer->cpumask)) @@ -3716,6 +3765,10 @@ int ring_buffer_read_page(struct ring_buffer *buffer, read = reader->read; commit = rb_page_commit(reader); + /* Check if any events were dropped */ + if (cpu_buffer->lost_events) + missed_events = 1; + /* * If this page has been partially read or * if len is not big enough to read the rest of the page or @@ -3779,6 +3832,13 @@ int ring_buffer_read_page(struct ring_buffer *buffer, } ret = read; + cpu_buffer->lost_events = 0; + /* + * Set a flag in the commit field if we lost events + */ + if (missed_events) + local_add(RB_MISSED_EVENTS, &bpage->commit); + out_unlock: spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags); diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c index df74c798225..dc56556b55a 100644 --- a/kernel/trace/ring_buffer_benchmark.c +++ b/kernel/trace/ring_buffer_benchmark.c @@ -81,7 +81,7 @@ static enum event_status read_event(int cpu) int *entry; u64 ts; - event = ring_buffer_consume(buffer, cpu, &ts); + event = ring_buffer_consume(buffer, cpu, &ts, NULL); if (!event) return EVENT_DROPPED; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3ec2ee6f656..fabb0033a9b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1556,7 +1556,7 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts) if (buf_iter) event = ring_buffer_iter_peek(buf_iter, ts); else - event = ring_buffer_peek(iter->tr->buffer, cpu, ts); + event = ring_buffer_peek(iter->tr->buffer, cpu, ts, NULL); ftrace_enable_cpu(); @@ -1635,7 +1635,7 @@ static void trace_consume(struct trace_iterator *iter) { /* Don't allow ftrace to trace into the ring buffers */ ftrace_disable_cpu(); - ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts); + ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts, NULL); ftrace_enable_cpu(); } diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index e6989d9b44d..a7f75fb10aa 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -489,9 +489,10 @@ get_return_for_leaf(struct trace_iterator *iter, * We need to consume the current entry to see * the next one. */ - ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL); + ring_buffer_consume(iter->tr->buffer, iter->cpu, + NULL, NULL); event = ring_buffer_peek(iter->tr->buffer, iter->cpu, - NULL); + NULL, NULL); } if (!event) diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 280fea470d6..e50180874c6 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -29,7 +29,7 @@ static int trace_test_buffer_cpu(struct trace_array *tr, int cpu) struct trace_entry *entry; unsigned int loops = 0; - while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) { + while ((event = ring_buffer_consume(tr->buffer, cpu, NULL, NULL))) { entry = ring_buffer_event_data(event); /* -- cgit v1.2.3-70-g09d2 From bc21b478425ac73f66a5ec0b375a5e0d12d609ce Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 31 Mar 2010 19:49:26 -0400 Subject: tracing: Show the lost events in the trace_pipe output Now that the ring buffer can keep track of where events are lost. Use this information to the output of trace_pipe: hackbench-3588 [001] 1326.701660: lock_acquire: ffffffff816591e0 read rcu_read_lock hackbench-3588 [001] 1326.701661: lock_acquire: ffff88003f4091f0 &(&dentry->d_lock)->rlock hackbench-3588 [001] 1326.701664: lock_release: ffff88003f4091f0 &(&dentry->d_lock)->rlock CPU:1 [LOST 673 EVENTS] hackbench-3588 [001] 1326.702711: kmem_cache_free: call_site=ffffffff81102b85 ptr=ffff880026d96738 hackbench-3588 [001] 1326.702712: lock_release: ffff88003e1480a8 &mm->mmap_sem hackbench-3588 [001] 1326.702713: lock_acquire: ffff88003e1480a8 &mm->mmap_sem Even works with the function graph tracer: 2) ! 170.098 us | } 2) 4.036 us | rcu_irq_exit(); 2) 3.657 us | idle_cpu(); 2) ! 190.301 us | } CPU:2 [LOST 2196 EVENTS] 2) 0.853 us | } /* cancel_dirty_page */ 2) | remove_from_page_cache() { 2) 1.578 us | _raw_spin_lock_irq(); 2) | __remove_from_page_cache() { Note, it does not work with the iterator "trace" file, since it requires the use of consuming the page from the ring buffer to determine how many events were lost, which the iterator does not do. Signed-off-by: Steven Rostedt --- include/linux/ftrace_event.h | 1 + kernel/trace/trace.c | 30 ++++++++++++++++++++++-------- 2 files changed, 23 insertions(+), 8 deletions(-) (limited to 'include') diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index c0f4b364c71..39e71b0a3bf 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -58,6 +58,7 @@ struct trace_iterator { /* The below is zeroed out in pipe_read */ struct trace_seq seq; struct trace_entry *ent; + unsigned long lost_events; int leftover; int cpu; u64 ts; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index fabb0033a9b..0498bebcbfd 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1545,7 +1545,8 @@ static void trace_iterator_increment(struct trace_iterator *iter) } static struct trace_entry * -peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts) +peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, + unsigned long *lost_events) { struct ring_buffer_event *event; struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu]; @@ -1556,7 +1557,8 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts) if (buf_iter) event = ring_buffer_iter_peek(buf_iter, ts); else - event = ring_buffer_peek(iter->tr->buffer, cpu, ts, NULL); + event = ring_buffer_peek(iter->tr->buffer, cpu, ts, + lost_events); ftrace_enable_cpu(); @@ -1564,10 +1566,12 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts) } static struct trace_entry * -__find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) +__find_next_entry(struct trace_iterator *iter, int *ent_cpu, + unsigned long *missing_events, u64 *ent_ts) { struct ring_buffer *buffer = iter->tr->buffer; struct trace_entry *ent, *next = NULL; + unsigned long lost_events, next_lost = 0; int cpu_file = iter->cpu_file; u64 next_ts = 0, ts; int next_cpu = -1; @@ -1580,7 +1584,7 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) if (cpu_file > TRACE_PIPE_ALL_CPU) { if (ring_buffer_empty_cpu(buffer, cpu_file)) return NULL; - ent = peek_next_entry(iter, cpu_file, ent_ts); + ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events); if (ent_cpu) *ent_cpu = cpu_file; @@ -1592,7 +1596,7 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) if (ring_buffer_empty_cpu(buffer, cpu)) continue; - ent = peek_next_entry(iter, cpu, &ts); + ent = peek_next_entry(iter, cpu, &ts, &lost_events); /* * Pick the entry with the smallest timestamp: @@ -1601,6 +1605,7 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) next = ent; next_cpu = cpu; next_ts = ts; + next_lost = lost_events; } } @@ -1610,6 +1615,9 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) if (ent_ts) *ent_ts = next_ts; + if (missing_events) + *missing_events = next_lost; + return next; } @@ -1617,13 +1625,14 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) { - return __find_next_entry(iter, ent_cpu, ent_ts); + return __find_next_entry(iter, ent_cpu, NULL, ent_ts); } /* Find the next real entry, and increment the iterator to the next entry */ static void *find_next_entry_inc(struct trace_iterator *iter) { - iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts); + iter->ent = __find_next_entry(iter, &iter->cpu, + &iter->lost_events, &iter->ts); if (iter->ent) trace_iterator_increment(iter); @@ -1635,7 +1644,8 @@ static void trace_consume(struct trace_iterator *iter) { /* Don't allow ftrace to trace into the ring buffers */ ftrace_disable_cpu(); - ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts, NULL); + ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts, + &iter->lost_events); ftrace_enable_cpu(); } @@ -2030,6 +2040,10 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter) { enum print_line_t ret; + if (iter->lost_events) + trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", + iter->cpu, iter->lost_events); + if (iter->trace && iter->trace->print_line) { ret = iter->trace->print_line(iter); if (ret != TRACE_TYPE_UNHANDLED) -- cgit v1.2.3-70-g09d2 From 897f0b3c3ff40b443c84e271bef19bd6ae885195 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 15 Mar 2010 10:10:03 +0100 Subject: sched: Kill the broken and deadlockable cpuset_lock/cpuset_cpus_allowed_locked code This patch just states the fact the cpusets/cpuhotplug interaction is broken and removes the deadlockable code which only pretends to work. - cpuset_lock() doesn't really work. It is needed for cpuset_cpus_allowed_locked() but we can't take this lock in try_to_wake_up()->select_fallback_rq() path. - cpuset_lock() is deadlockable. Suppose that a task T bound to CPU takes callback_mutex. If cpu_down(CPU) happens before T drops callback_mutex stop_machine() preempts T, then migration_call(CPU_DEAD) tries to take cpuset_lock() and hangs forever because CPU is already dead and thus T can't be scheduled. - cpuset_cpus_allowed_locked() is deadlockable too. It takes task_lock() which is not irq-safe, but try_to_wake_up() can be called from irq. Kill them, and change select_fallback_rq() to use cpu_possible_mask, like we currently do without CONFIG_CPUSETS. Also, with or without this patch, with or without CONFIG_CPUSETS, the callers of select_fallback_rq() can race with each other or with set_cpus_allowed() pathes. The subsequent patches try to to fix these problems. Signed-off-by: Oleg Nesterov Signed-off-by: Peter Zijlstra LKML-Reference: <20100315091003.GA9123@redhat.com> Signed-off-by: Ingo Molnar --- include/linux/cpuset.h | 13 ------------- kernel/cpuset.c | 27 +-------------------------- kernel/sched.c | 10 +++------- 3 files changed, 4 insertions(+), 46 deletions(-) (limited to 'include') diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index a5740fc4d04..eeaaee746be 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -21,8 +21,6 @@ extern int number_of_cpusets; /* How many cpusets are defined in system? */ extern int cpuset_init(void); extern void cpuset_init_smp(void); extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask); -extern void cpuset_cpus_allowed_locked(struct task_struct *p, - struct cpumask *mask); extern nodemask_t cpuset_mems_allowed(struct task_struct *p); #define cpuset_current_mems_allowed (current->mems_allowed) void cpuset_init_current_mems_allowed(void); @@ -69,9 +67,6 @@ struct seq_file; extern void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task); -extern void cpuset_lock(void); -extern void cpuset_unlock(void); - extern int cpuset_mem_spread_node(void); static inline int cpuset_do_page_mem_spread(void) @@ -105,11 +100,6 @@ static inline void cpuset_cpus_allowed(struct task_struct *p, { cpumask_copy(mask, cpu_possible_mask); } -static inline void cpuset_cpus_allowed_locked(struct task_struct *p, - struct cpumask *mask) -{ - cpumask_copy(mask, cpu_possible_mask); -} static inline nodemask_t cpuset_mems_allowed(struct task_struct *p) { @@ -157,9 +147,6 @@ static inline void cpuset_task_status_allowed(struct seq_file *m, { } -static inline void cpuset_lock(void) {} -static inline void cpuset_unlock(void) {} - static inline int cpuset_mem_spread_node(void) { return 0; diff --git a/kernel/cpuset.c b/kernel/cpuset.c index d10946748ec..9a747f56d58 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2182,19 +2182,10 @@ void __init cpuset_init_smp(void) void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) { mutex_lock(&callback_mutex); - cpuset_cpus_allowed_locked(tsk, pmask); - mutex_unlock(&callback_mutex); -} - -/** - * cpuset_cpus_allowed_locked - return cpus_allowed mask from a tasks cpuset. - * Must be called with callback_mutex held. - **/ -void cpuset_cpus_allowed_locked(struct task_struct *tsk, struct cpumask *pmask) -{ task_lock(tsk); guarantee_online_cpus(task_cs(tsk), pmask); task_unlock(tsk); + mutex_unlock(&callback_mutex); } void cpuset_init_current_mems_allowed(void) @@ -2382,22 +2373,6 @@ int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask) return 0; } -/** - * cpuset_lock - lock out any changes to cpuset structures - * - * The out of memory (oom) code needs to mutex_lock cpusets - * from being changed while it scans the tasklist looking for a - * task in an overlapping cpuset. Expose callback_mutex via this - * cpuset_lock() routine, so the oom code can lock it, before - * locking the task list. The tasklist_lock is a spinlock, so - * must be taken inside callback_mutex. - */ - -void cpuset_lock(void) -{ - mutex_lock(&callback_mutex); -} - /** * cpuset_unlock - release lock on cpuset changes * diff --git a/kernel/sched.c b/kernel/sched.c index 52b7efd2741..c0b3ebc1631 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2296,11 +2296,9 @@ static int select_fallback_rq(int cpu, struct task_struct *p) return dest_cpu; /* No more Mr. Nice Guy. */ - if (dest_cpu >= nr_cpu_ids) { - rcu_read_lock(); - cpuset_cpus_allowed_locked(p, &p->cpus_allowed); - rcu_read_unlock(); - dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed); + if (unlikely(dest_cpu >= nr_cpu_ids)) { + cpumask_copy(&p->cpus_allowed, cpu_possible_mask); + dest_cpu = cpumask_any(cpu_active_mask); /* * Don't tell them about moving exiting tasks or @@ -5866,7 +5864,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) case CPU_DEAD: case CPU_DEAD_FROZEN: - cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */ migrate_live_tasks(cpu); rq = cpu_rq(cpu); kthread_stop(rq->migration_thread); @@ -5879,7 +5876,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) rq->idle->sched_class = &idle_sched_class; migrate_dead_tasks(cpu); raw_spin_unlock_irq(&rq->lock); - cpuset_unlock(); migrate_nr_uninterruptible(rq); BUG_ON(rq->nr_running != 0); calc_global_load_remove(rq); -- cgit v1.2.3-70-g09d2 From 6a1bdc1b577ebcb65f6603c57f8347309bc4ab13 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 15 Mar 2010 10:10:23 +0100 Subject: sched: _cpu_down(): Don't play with current->cpus_allowed _cpu_down() changes the current task's affinity and then recovers it at the end. The problems are well known: we can't restore old_allowed if it was bound to the now-dead-cpu, and we can race with the userspace which can change cpu-affinity during unplug. _cpu_down() should not play with current->cpus_allowed at all. Instead, take_cpu_down() can migrate the caller of _cpu_down() after __cpu_disable() removes the dying cpu from cpu_online_mask. Signed-off-by: Oleg Nesterov Acked-by: Rafael J. Wysocki Signed-off-by: Peter Zijlstra LKML-Reference: <20100315091023.GA9148@redhat.com> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 1 + kernel/cpu.c | 18 ++++++------------ kernel/sched.c | 2 +- 3 files changed, 8 insertions(+), 13 deletions(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 43c94515273..8bea40725c7 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1843,6 +1843,7 @@ extern void sched_clock_idle_sleep_event(void); extern void sched_clock_idle_wakeup_event(u64 delta_ns); #ifdef CONFIG_HOTPLUG_CPU +extern void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p); extern void idle_task_exit(void); #else static inline void idle_task_exit(void) {} diff --git a/kernel/cpu.c b/kernel/cpu.c index f8cced2692b..8d340faac38 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -163,6 +163,7 @@ static inline void check_for_tasks(int cpu) } struct take_cpu_down_param { + struct task_struct *caller; unsigned long mod; void *hcpu; }; @@ -171,6 +172,7 @@ struct take_cpu_down_param { static int __ref take_cpu_down(void *_param) { struct take_cpu_down_param *param = _param; + unsigned int cpu = (unsigned long)param->hcpu; int err; /* Ensure this CPU doesn't handle any more interrupts. */ @@ -181,6 +183,8 @@ static int __ref take_cpu_down(void *_param) raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod, param->hcpu); + if (task_cpu(param->caller) == cpu) + move_task_off_dead_cpu(cpu, param->caller); /* Force idle task to run as soon as we yield: it should immediately notice cpu is offline and die quickly. */ sched_idle_next(); @@ -191,10 +195,10 @@ static int __ref take_cpu_down(void *_param) static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) { int err, nr_calls = 0; - cpumask_var_t old_allowed; void *hcpu = (void *)(long)cpu; unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; struct take_cpu_down_param tcd_param = { + .caller = current, .mod = mod, .hcpu = hcpu, }; @@ -205,9 +209,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) if (!cpu_online(cpu)) return -EINVAL; - if (!alloc_cpumask_var(&old_allowed, GFP_KERNEL)) - return -ENOMEM; - cpu_hotplug_begin(); set_cpu_active(cpu, false); err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod, @@ -224,10 +225,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) goto out_release; } - /* Ensure that we are not runnable on dying cpu */ - cpumask_copy(old_allowed, ¤t->cpus_allowed); - set_cpus_allowed_ptr(current, cpu_active_mask); - err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); if (err) { set_cpu_active(cpu, true); @@ -236,7 +233,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) hcpu) == NOTIFY_BAD) BUG(); - goto out_allowed; + goto out_release; } BUG_ON(cpu_online(cpu)); @@ -254,8 +251,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) check_for_tasks(cpu); -out_allowed: - set_cpus_allowed_ptr(current, old_allowed); out_release: cpu_hotplug_done(); if (!err) { @@ -263,7 +258,6 @@ out_release: hcpu) == NOTIFY_BAD) BUG(); } - free_cpumask_var(old_allowed); return err; } diff --git a/kernel/sched.c b/kernel/sched.c index 165b532dd8c..11119deffa4 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5442,7 +5442,7 @@ static int migration_thread(void *data) /* * Figure out where task on dead CPU should go, use force if necessary. */ -static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) +void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) { struct rq *rq = cpu_rq(dead_cpu); int needs_cpu, uninitialized_var(dest_cpu); -- cgit v1.2.3-70-g09d2 From 9084bb8246ea935b98320554229e2f371f7f52fa Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 15 Mar 2010 10:10:27 +0100 Subject: sched: Make select_fallback_rq() cpuset friendly Introduce cpuset_cpus_allowed_fallback() helper to fix the cpuset problems with select_fallback_rq(). It can be called from any context and can't use any cpuset locks including task_lock(). It is called when the task doesn't have online cpus in ->cpus_allowed but ttwu/etc must be able to find a suitable cpu. I am not proud of this patch. Everything which needs such a fat comment can't be good even if correct. But I'd prefer to not change the locking rules in the code I hardly understand, and in any case I believe this simple change make the code much more correct compared to deadlocks we currently have. Signed-off-by: Oleg Nesterov Signed-off-by: Peter Zijlstra LKML-Reference: <20100315091027.GA9155@redhat.com> Signed-off-by: Ingo Molnar --- include/linux/cpuset.h | 7 +++++++ kernel/cpuset.c | 42 ++++++++++++++++++++++++++++++++++++++++++ kernel/sched.c | 4 +--- 3 files changed, 50 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index eeaaee746be..a73454aec33 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -21,6 +21,7 @@ extern int number_of_cpusets; /* How many cpusets are defined in system? */ extern int cpuset_init(void); extern void cpuset_init_smp(void); extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask); +extern int cpuset_cpus_allowed_fallback(struct task_struct *p); extern nodemask_t cpuset_mems_allowed(struct task_struct *p); #define cpuset_current_mems_allowed (current->mems_allowed) void cpuset_init_current_mems_allowed(void); @@ -101,6 +102,12 @@ static inline void cpuset_cpus_allowed(struct task_struct *p, cpumask_copy(mask, cpu_possible_mask); } +static inline int cpuset_cpus_allowed_fallback(struct task_struct *p) +{ + cpumask_copy(&p->cpus_allowed, cpu_possible_mask); + return cpumask_any(cpu_active_mask); +} + static inline nodemask_t cpuset_mems_allowed(struct task_struct *p) { return node_possible_map; diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 9a747f56d58..9a50c5f6e72 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2188,6 +2188,48 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) mutex_unlock(&callback_mutex); } +int cpuset_cpus_allowed_fallback(struct task_struct *tsk) +{ + const struct cpuset *cs; + int cpu; + + rcu_read_lock(); + cs = task_cs(tsk); + if (cs) + cpumask_copy(&tsk->cpus_allowed, cs->cpus_allowed); + rcu_read_unlock(); + + /* + * We own tsk->cpus_allowed, nobody can change it under us. + * + * But we used cs && cs->cpus_allowed lockless and thus can + * race with cgroup_attach_task() or update_cpumask() and get + * the wrong tsk->cpus_allowed. However, both cases imply the + * subsequent cpuset_change_cpumask()->set_cpus_allowed_ptr() + * which takes task_rq_lock(). + * + * If we are called after it dropped the lock we must see all + * changes in tsk_cs()->cpus_allowed. Otherwise we can temporary + * set any mask even if it is not right from task_cs() pov, + * the pending set_cpus_allowed_ptr() will fix things. + */ + + cpu = cpumask_any_and(&tsk->cpus_allowed, cpu_active_mask); + if (cpu >= nr_cpu_ids) { + /* + * Either tsk->cpus_allowed is wrong (see above) or it + * is actually empty. The latter case is only possible + * if we are racing with remove_tasks_in_empty_cpuset(). + * Like above we can temporary set any mask and rely on + * set_cpus_allowed_ptr() as synchronization point. + */ + cpumask_copy(&tsk->cpus_allowed, cpu_possible_mask); + cpu = cpumask_any(cpu_active_mask); + } + + return cpu; +} + void cpuset_init_current_mems_allowed(void) { nodes_setall(current->mems_allowed); diff --git a/kernel/sched.c b/kernel/sched.c index 11119deffa4..9a38c7a24ed 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2300,9 +2300,7 @@ static int select_fallback_rq(int cpu, struct task_struct *p) /* No more Mr. Nice Guy. */ if (unlikely(dest_cpu >= nr_cpu_ids)) { - cpumask_copy(&p->cpus_allowed, cpu_possible_mask); - dest_cpu = cpumask_any(cpu_active_mask); - + dest_cpu = cpuset_cpus_allowed_fallback(p); /* * Don't tell them about moving exiting tasks or * kernel threads (both mm NULL), since they never -- cgit v1.2.3-70-g09d2 From 0017d735092844118bef006696a750a0e4ef6ebd Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 24 Mar 2010 18:34:10 +0100 Subject: sched: Fix TASK_WAKING vs fork deadlock Oleg noticed a few races with the TASK_WAKING usage on fork. - since TASK_WAKING is basically a spinlock, it should be IRQ safe - since we set TASK_WAKING (*) without holding rq->lock it could be there still is a rq->lock holder, thereby not actually providing full serialization. (*) in fact we clear PF_STARTING, which in effect enables TASK_WAKING. Cure the second issue by not setting TASK_WAKING in sched_fork(), but only temporarily in wake_up_new_task() while calling select_task_rq(). Cure the first by holding rq->lock around the select_task_rq() call, this will disable IRQs, this however requires that we push down the rq->lock release into select_task_rq_fair()'s cgroup stuff. Because select_task_rq_fair() still needs to drop the rq->lock we cannot fully get rid of TASK_WAKING. Reported-by: Oleg Nesterov Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- include/linux/sched.h | 3 ++- kernel/sched.c | 65 ++++++++++++++++++------------------------------- kernel/sched_fair.c | 8 ++++-- kernel/sched_idletask.c | 3 ++- kernel/sched_rt.c | 5 ++-- 5 files changed, 36 insertions(+), 48 deletions(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 8bea40725c7..fb6c18843ee 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1046,7 +1046,8 @@ struct sched_class { void (*put_prev_task) (struct rq *rq, struct task_struct *p); #ifdef CONFIG_SMP - int (*select_task_rq)(struct task_struct *p, int sd_flag, int flags); + int (*select_task_rq)(struct rq *rq, struct task_struct *p, + int sd_flag, int flags); void (*pre_schedule) (struct rq *this_rq, struct task_struct *task); void (*post_schedule) (struct rq *this_rq); diff --git a/kernel/sched.c b/kernel/sched.c index 9a38c7a24ed..dcd17736dae 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -916,14 +916,10 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) /* * Check whether the task is waking, we use this to synchronize against * ttwu() so that task_cpu() reports a stable number. - * - * We need to make an exception for PF_STARTING tasks because the fork - * path might require task_rq_lock() to work, eg. it can call - * set_cpus_allowed_ptr() from the cpuset clone_ns code. */ static inline int task_is_waking(struct task_struct *p) { - return unlikely((p->state == TASK_WAKING) && !(p->flags & PF_STARTING)); + return unlikely(p->state == TASK_WAKING); } /* @@ -2320,9 +2316,9 @@ static int select_fallback_rq(int cpu, struct task_struct *p) * The caller (fork, wakeup) owns TASK_WAKING, ->cpus_allowed is stable. */ static inline -int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) +int select_task_rq(struct rq *rq, struct task_struct *p, int sd_flags, int wake_flags) { - int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); + int cpu = p->sched_class->select_task_rq(rq, p, sd_flags, wake_flags); /* * In order not to call set_task_cpu() on a blocking task we need @@ -2393,17 +2389,10 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, if (p->sched_class->task_waking) p->sched_class->task_waking(rq, p); - __task_rq_unlock(rq); - - cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); - if (cpu != orig_cpu) { - /* - * Since we migrate the task without holding any rq->lock, - * we need to be careful with task_rq_lock(), since that - * might end up locking an invalid rq. - */ + cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags); + if (cpu != orig_cpu) set_task_cpu(p, cpu); - } + __task_rq_unlock(rq); rq = cpu_rq(cpu); raw_spin_lock(&rq->lock); @@ -2530,11 +2519,11 @@ void sched_fork(struct task_struct *p, int clone_flags) __sched_fork(p); /* - * We mark the process as waking here. This guarantees that + * We mark the process as running here. This guarantees that * nobody will actually run it, and a signal or other external * event cannot wake it up and insert it on the runqueue either. */ - p->state = TASK_WAKING; + p->state = TASK_RUNNING; /* * Revert to default priority/policy on fork if requested. @@ -2601,28 +2590,25 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) int cpu __maybe_unused = get_cpu(); #ifdef CONFIG_SMP + rq = task_rq_lock(p, &flags); + p->state = TASK_WAKING; + /* * Fork balancing, do it here and not earlier because: * - cpus_allowed can change in the fork path * - any previously selected cpu might disappear through hotplug * - * We still have TASK_WAKING but PF_STARTING is gone now, meaning - * ->cpus_allowed is stable, we have preemption disabled, meaning - * cpu_online_mask is stable. + * We set TASK_WAKING so that select_task_rq() can drop rq->lock + * without people poking at ->cpus_allowed. */ - cpu = select_task_rq(p, SD_BALANCE_FORK, 0); + cpu = select_task_rq(rq, p, SD_BALANCE_FORK, 0); set_task_cpu(p, cpu); -#endif - - /* - * Since the task is not on the rq and we still have TASK_WAKING set - * nobody else will migrate this task. - */ - rq = cpu_rq(cpu); - raw_spin_lock_irqsave(&rq->lock, flags); - BUG_ON(p->state != TASK_WAKING); p->state = TASK_RUNNING; + task_rq_unlock(rq, &flags); +#endif + + rq = task_rq_lock(p, &flags); activate_task(rq, p, 0); trace_sched_wakeup_new(rq, p, 1); check_preempt_curr(rq, p, WF_FORK); @@ -3068,19 +3054,15 @@ void sched_exec(void) { struct task_struct *p = current; struct migration_req req; - int dest_cpu, this_cpu; unsigned long flags; struct rq *rq; - - this_cpu = get_cpu(); - dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0); - if (dest_cpu == this_cpu) { - put_cpu(); - return; - } + int dest_cpu; rq = task_rq_lock(p, &flags); - put_cpu(); + dest_cpu = p->sched_class->select_task_rq(rq, p, SD_BALANCE_EXEC, 0); + if (dest_cpu == smp_processor_id()) + goto unlock; + /* * select_task_rq() can race against ->cpus_allowed */ @@ -3098,6 +3080,7 @@ void sched_exec(void) return; } +unlock: task_rq_unlock(rq, &flags); } diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 49ad99378f8..8a5e7632d09 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1423,7 +1423,8 @@ select_idle_sibling(struct task_struct *p, struct sched_domain *sd, int target) * * preempt must be disabled. */ -static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags) +static int +select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_flags) { struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL; int cpu = smp_processor_id(); @@ -1521,8 +1522,11 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag cpumask_weight(sched_domain_span(sd)))) tmp = affine_sd; - if (tmp) + if (tmp) { + raw_spin_unlock(&rq->lock); update_shares(tmp); + raw_spin_lock(&rq->lock); + } } #endif diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index a8a6d8a5094..5af709f503b 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -6,7 +6,8 @@ */ #ifdef CONFIG_SMP -static int select_task_rq_idle(struct task_struct *p, int sd_flag, int flags) +static int +select_task_rq_idle(struct rq *rq, struct task_struct *p, int sd_flag, int flags) { return task_cpu(p); /* IDLE tasks as never migrated */ } diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 012d69bb67c..fde895f8044 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -948,10 +948,9 @@ static void yield_task_rt(struct rq *rq) #ifdef CONFIG_SMP static int find_lowest_rq(struct task_struct *task); -static int select_task_rq_rt(struct task_struct *p, int sd_flag, int flags) +static int +select_task_rq_rt(struct rq *rq, struct task_struct *p, int sd_flag, int flags) { - struct rq *rq = task_rq(p); - if (sd_flag != SD_BALANCE_WAKE) return smp_processor_id(); -- cgit v1.2.3-70-g09d2 From 371fd7e7a56a5c136d31aa980011bd2f131c3ef5 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 24 Mar 2010 16:38:48 +0100 Subject: sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- include/linux/sched.h | 11 ++++++++--- kernel/sched.c | 32 +++++++++++++++++--------------- kernel/sched_fair.c | 25 ++++++++----------------- kernel/sched_idletask.c | 2 +- kernel/sched_rt.c | 8 ++++---- 5 files changed, 38 insertions(+), 40 deletions(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index fb6c18843ee..e3e900f318d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1032,12 +1032,17 @@ struct sched_domain; #define WF_SYNC 0x01 /* waker goes to sleep after wakup */ #define WF_FORK 0x02 /* child wakeup after fork */ +#define ENQUEUE_WAKEUP 1 +#define ENQUEUE_WAKING 2 +#define ENQUEUE_HEAD 4 + +#define DEQUEUE_SLEEP 1 + struct sched_class { const struct sched_class *next; - void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup, - bool head); - void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep); + void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); + void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); void (*yield_task) (struct rq *rq); void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags); diff --git a/kernel/sched.c b/kernel/sched.c index 14c8d2a1b38..4a57e96dd6c 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1877,44 +1877,43 @@ static void update_avg(u64 *avg, u64 sample) *avg += diff >> 3; } -static void -enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head) +static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) { update_rq_clock(rq); sched_info_queued(p); - p->sched_class->enqueue_task(rq, p, wakeup, head); + p->sched_class->enqueue_task(rq, p, flags); p->se.on_rq = 1; } -static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) +static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) { update_rq_clock(rq); sched_info_dequeued(p); - p->sched_class->dequeue_task(rq, p, sleep); + p->sched_class->dequeue_task(rq, p, flags); p->se.on_rq = 0; } /* * activate_task - move a task to the runqueue. */ -static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) +static void activate_task(struct rq *rq, struct task_struct *p, int flags) { if (task_contributes_to_load(p)) rq->nr_uninterruptible--; - enqueue_task(rq, p, wakeup, false); + enqueue_task(rq, p, flags); inc_nr_running(rq); } /* * deactivate_task - remove a task from the runqueue. */ -static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) +static void deactivate_task(struct rq *rq, struct task_struct *p, int flags) { if (task_contributes_to_load(p)) rq->nr_uninterruptible++; - dequeue_task(rq, p, sleep); + dequeue_task(rq, p, flags); dec_nr_running(rq); } @@ -2353,6 +2352,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, { int cpu, orig_cpu, this_cpu, success = 0; unsigned long flags; + unsigned long en_flags = ENQUEUE_WAKEUP; struct rq *rq; this_cpu = get_cpu(); @@ -2386,8 +2386,10 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, } p->state = TASK_WAKING; - if (p->sched_class->task_waking) + if (p->sched_class->task_waking) { p->sched_class->task_waking(rq, p); + en_flags |= ENQUEUE_WAKING; + } cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags); if (cpu != orig_cpu) @@ -2432,7 +2434,7 @@ out_activate: schedstat_inc(p, se.statistics.nr_wakeups_local); else schedstat_inc(p, se.statistics.nr_wakeups_remote); - activate_task(rq, p, 1); + activate_task(rq, p, en_flags); success = 1; out_running: @@ -3623,7 +3625,7 @@ need_resched_nonpreemptible: if (unlikely(signal_pending_state(prev->state, prev))) prev->state = TASK_RUNNING; else - deactivate_task(rq, prev, 1); + deactivate_task(rq, prev, DEQUEUE_SLEEP); switch_count = &prev->nvcsw; } @@ -4193,7 +4195,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio) if (running) p->sched_class->set_curr_task(rq); if (on_rq) { - enqueue_task(rq, p, 0, oldprio < prio); + enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0); check_class_changed(rq, p, prev_class, oldprio, running); } @@ -4236,7 +4238,7 @@ void set_user_nice(struct task_struct *p, long nice) delta = p->prio - old_prio; if (on_rq) { - enqueue_task(rq, p, 0, false); + enqueue_task(rq, p, 0); /* * If the task increased its priority or is running and * lowered its priority, then reschedule its CPU: @@ -8180,7 +8182,7 @@ void sched_move_task(struct task_struct *tsk) if (unlikely(running)) tsk->sched_class->set_curr_task(rq); if (on_rq) - enqueue_task(rq, tsk, 0, false); + enqueue_task(rq, tsk, 0); task_rq_unlock(rq, &flags); } diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 8a5e7632d09..88d3053ac7c 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -757,9 +757,6 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) se->vruntime = vruntime; } -#define ENQUEUE_WAKEUP 1 -#define ENQUEUE_MIGRATE 2 - static void enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) { @@ -767,7 +764,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) * Update the normalized vruntime before updating min_vruntime * through callig update_curr(). */ - if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_MIGRATE)) + if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING)) se->vruntime += cfs_rq->min_vruntime; /* @@ -803,7 +800,7 @@ static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se) } static void -dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) +dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) { /* * Update run-time statistics of the 'current'. @@ -811,7 +808,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) update_curr(cfs_rq); update_stats_dequeue(cfs_rq, se); - if (sleep) { + if (flags & DEQUEUE_SLEEP) { #ifdef CONFIG_SCHEDSTATS if (entity_is_task(se)) { struct task_struct *tsk = task_of(se); @@ -836,7 +833,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) * update can refer to the ->curr item and we need to reflect this * movement in our normalized position. */ - if (!sleep) + if (!(flags & DEQUEUE_SLEEP)) se->vruntime -= cfs_rq->min_vruntime; } @@ -1045,16 +1042,10 @@ static inline void hrtick_update(struct rq *rq) * then put the task into the rbtree: */ static void -enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup, bool head) +enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) { struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; - int flags = 0; - - if (wakeup) - flags |= ENQUEUE_WAKEUP; - if (p->state == TASK_WAKING) - flags |= ENQUEUE_MIGRATE; for_each_sched_entity(se) { if (se->on_rq) @@ -1072,18 +1063,18 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup, bool head) * decreased. We remove the task from the rbtree and * update the fair scheduling stats: */ -static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep) +static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) { struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); - dequeue_entity(cfs_rq, se, sleep); + dequeue_entity(cfs_rq, se, flags); /* Don't dequeue parent if it has other entities besides us */ if (cfs_rq->load.weight) break; - sleep = 1; + flags |= DEQUEUE_SLEEP; } hrtick_update(rq); diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index 5af709f503b..bea2b8f1202 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -33,7 +33,7 @@ static struct task_struct *pick_next_task_idle(struct rq *rq) * message if some code attempts to do it: */ static void -dequeue_task_idle(struct rq *rq, struct task_struct *p, int sleep) +dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags) { raw_spin_unlock_irq(&rq->lock); printk(KERN_ERR "bad: scheduling from the idle thread!\n"); diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index fde895f8044..8afb953e31c 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -888,20 +888,20 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se) * Adding/removing a task to/from a priority array: */ static void -enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup, bool head) +enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) { struct sched_rt_entity *rt_se = &p->rt; - if (wakeup) + if (flags & ENQUEUE_WAKEUP) rt_se->timeout = 0; - enqueue_rt_entity(rt_se, head); + enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD); if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1) enqueue_pushable_task(rq, p); } -static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep) +static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags) { struct sched_rt_entity *rt_se = &p->rt; -- cgit v1.2.3-70-g09d2 From 6cc8a7c1d8560c042f486b23318a6291569ab96b Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 19 Mar 2010 01:23:53 +0100 Subject: perf: Fetch hot regs from the template caller Trace events can be defined from a template using DECLARE_EVENT_CLASS/DEFINE_EVENT or directly with TRACE_EVENT. In both cases we have a template tracepoint handler, used to record the trace, to which we pass our ftrace event instance. In the function level, if the class is named "foo" and the event is named "blah", we have the following chain of calls: perf_trace_blah() -> perf_trace_templ_foo() In the case we have several events sharing the class "blah", we'll have multiple users of perf_trace_templ_foo(), and it won't be inlined by the compiler. This is usually what happens with the DECLARE_EVENT_CLASS/DEFINE_EVENT based definition. But if perf_trace_blah() is the only caller of perf_trace_templ_foo() there are fair chances that it will be inlined. The problem is that we fetch the regs from perf_trace_templ_foo() after we rewinded the frame pointer to the second caller, we want to reach the caller of perf_trace_blah() to get the right source of the event. And we do this by always assuming that perf_trace_templ_foo() is not inlined. But as shown above this is not always true. And if it is inlined we miss the first caller, losing the most important level of precision. We get: 61.31% ls [kernel.kallsyms] [k] do_softirq | --- do_softirq irq_exit do_IRQ common_interrupt | |--25.00%-- tty_buffer_request_room Instead of: 61.31% ls [kernel.kallsyms] [k] __do_softirq | --- __do_softirq do_softirq irq_exit do_IRQ common_interrupt | |--25.00%-- tty_buffer_request_room To fix this, we fetch the regs from perf_trace_blah() rather than perf_trace_templ_foo() so that we don't have to deal with inlining surprises. That also bring us the advantage of having the true source of the event even if we don't have frame pointers. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Ingo Molnar --- include/trace/ftrace.h | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index ea6f9d4a20e..882c64832ff 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -758,13 +758,12 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ static notrace void \ perf_trace_templ_##call(struct ftrace_event_call *event_call, \ - proto) \ + struct pt_regs *__regs, proto) \ { \ struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\ struct ftrace_raw_##call *entry; \ u64 __addr = 0, __count = 1; \ unsigned long irq_flags; \ - struct pt_regs *__regs; \ int __entry_size; \ int __data_size; \ int rctx; \ @@ -785,20 +784,22 @@ perf_trace_templ_##call(struct ftrace_event_call *event_call, \ \ { assign; } \ \ - __regs = &__get_cpu_var(perf_trace_regs); \ - perf_fetch_caller_regs(__regs, 2); \ - \ perf_trace_buf_submit(entry, __entry_size, rctx, __addr, \ __count, irq_flags, __regs); \ } #undef DEFINE_EVENT -#define DEFINE_EVENT(template, call, proto, args) \ -static notrace void perf_trace_##call(proto) \ -{ \ - struct ftrace_event_call *event_call = &event_##call; \ - \ - perf_trace_templ_##template(event_call, args); \ +#define DEFINE_EVENT(template, call, proto, args) \ +static notrace void perf_trace_##call(proto) \ +{ \ + struct ftrace_event_call *event_call = &event_##call; \ + struct pt_regs *__regs = &get_cpu_var(perf_trace_regs); \ + \ + perf_fetch_caller_regs(__regs, 1); \ + \ + perf_trace_templ_##template(event_call, __regs, args); \ + \ + put_cpu_var(perf_trace_regs); \ } #undef DEFINE_EVENT_PRINT -- cgit v1.2.3-70-g09d2 From 1527bc8b928dd1399c3d3467dd47d9ede210978a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 1 Feb 2010 15:03:07 +0100 Subject: bitops: Optimize hweight() by making use of compile-time evaluation Rename the extisting runtime hweight() implementations to __arch_hweight(), rename the compile-time versions to __const_hweight() and then have hweight() pick between them. Suggested-by: H. Peter Anvin Signed-off-by: Peter Zijlstra LKML-Reference: <20100318111929.GB11152@aftab> Acked-by: H. Peter Anvin LKML-Reference: <1265028224.24455.154.camel@laptop> Signed-off-by: H. Peter Anvin --- arch/alpha/include/asm/bitops.h | 18 +++++++------ arch/ia64/include/asm/bitops.h | 11 ++++---- arch/sparc/include/asm/bitops_64.h | 11 ++++---- include/asm-generic/bitops/arch_hweight.h | 11 ++++++++ include/asm-generic/bitops/const_hweight.h | 42 ++++++++++++++++++++++++++++++ include/asm-generic/bitops/hweight.h | 8 ++---- include/linux/bitops.h | 25 ------------------ lib/hweight.c | 19 +++++++------- 8 files changed, 87 insertions(+), 58 deletions(-) create mode 100644 include/asm-generic/bitops/arch_hweight.h create mode 100644 include/asm-generic/bitops/const_hweight.h (limited to 'include') diff --git a/arch/alpha/include/asm/bitops.h b/arch/alpha/include/asm/bitops.h index 15f3ae25c51..296da1d5ed5 100644 --- a/arch/alpha/include/asm/bitops.h +++ b/arch/alpha/include/asm/bitops.h @@ -405,29 +405,31 @@ static inline int fls(int x) #if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67) /* Whee. EV67 can calculate it directly. */ -static inline unsigned long hweight64(unsigned long w) +static inline unsigned long __arch_hweight64(unsigned long w) { return __kernel_ctpop(w); } -static inline unsigned int hweight32(unsigned int w) +static inline unsigned int __arch_weight32(unsigned int w) { - return hweight64(w); + return __arch_hweight64(w); } -static inline unsigned int hweight16(unsigned int w) +static inline unsigned int __arch_hweight16(unsigned int w) { - return hweight64(w & 0xffff); + return __arch_hweight64(w & 0xffff); } -static inline unsigned int hweight8(unsigned int w) +static inline unsigned int __arch_hweight8(unsigned int w) { - return hweight64(w & 0xff); + return __arch_hweight64(w & 0xff); } #else -#include +#include #endif +#include + #endif /* __KERNEL__ */ #include diff --git a/arch/ia64/include/asm/bitops.h b/arch/ia64/include/asm/bitops.h index 6ebc229a1c5..9da3df6f1a5 100644 --- a/arch/ia64/include/asm/bitops.h +++ b/arch/ia64/include/asm/bitops.h @@ -437,17 +437,18 @@ __fls (unsigned long x) * hweightN: returns the hamming weight (i.e. the number * of bits set) of a N-bit word */ -static __inline__ unsigned long -hweight64 (unsigned long x) +static __inline__ unsigned long __arch_hweight64(unsigned long x) { unsigned long result; result = ia64_popcnt(x); return result; } -#define hweight32(x) (unsigned int) hweight64((x) & 0xfffffffful) -#define hweight16(x) (unsigned int) hweight64((x) & 0xfffful) -#define hweight8(x) (unsigned int) hweight64((x) & 0xfful) +#define __arch_hweight32(x) ((unsigned int) __arch_hweight64((x) & 0xfffffffful)) +#define __arch_hweight16(x) ((unsigned int) __arch_hweight64((x) & 0xfffful)) +#define __arch_hweight8(x) ((unsigned int) __arch_hweight64((x) & 0xfful)) + +#include #endif /* __KERNEL__ */ diff --git a/arch/sparc/include/asm/bitops_64.h b/arch/sparc/include/asm/bitops_64.h index e72ac9cdfb9..766121a67a2 100644 --- a/arch/sparc/include/asm/bitops_64.h +++ b/arch/sparc/include/asm/bitops_64.h @@ -44,7 +44,7 @@ extern void change_bit(unsigned long nr, volatile unsigned long *addr); #ifdef ULTRA_HAS_POPULATION_COUNT -static inline unsigned int hweight64(unsigned long w) +static inline unsigned int __arch_hweight64(unsigned long w) { unsigned int res; @@ -52,7 +52,7 @@ static inline unsigned int hweight64(unsigned long w) return res; } -static inline unsigned int hweight32(unsigned int w) +static inline unsigned int __arch_hweight32(unsigned int w) { unsigned int res; @@ -60,7 +60,7 @@ static inline unsigned int hweight32(unsigned int w) return res; } -static inline unsigned int hweight16(unsigned int w) +static inline unsigned int __arch_hweight16(unsigned int w) { unsigned int res; @@ -68,7 +68,7 @@ static inline unsigned int hweight16(unsigned int w) return res; } -static inline unsigned int hweight8(unsigned int w) +static inline unsigned int __arch_hweight8(unsigned int w) { unsigned int res; @@ -78,9 +78,10 @@ static inline unsigned int hweight8(unsigned int w) #else -#include +#include #endif +#include #include #endif /* __KERNEL__ */ diff --git a/include/asm-generic/bitops/arch_hweight.h b/include/asm-generic/bitops/arch_hweight.h new file mode 100644 index 00000000000..3a7be842cdc --- /dev/null +++ b/include/asm-generic/bitops/arch_hweight.h @@ -0,0 +1,11 @@ +#ifndef _ASM_GENERIC_BITOPS_ARCH_HWEIGHT_H_ +#define _ASM_GENERIC_BITOPS_ARCH_HWEIGHT_H_ + +#include + +extern unsigned int __arch_hweight32(unsigned int w); +extern unsigned int __arch_hweight16(unsigned int w); +extern unsigned int __arch_hweight8(unsigned int w); +extern unsigned long __arch_hweight64(__u64 w); + +#endif /* _ASM_GENERIC_BITOPS_HWEIGHT_H_ */ diff --git a/include/asm-generic/bitops/const_hweight.h b/include/asm-generic/bitops/const_hweight.h new file mode 100644 index 00000000000..fa2a50b7ee6 --- /dev/null +++ b/include/asm-generic/bitops/const_hweight.h @@ -0,0 +1,42 @@ +#ifndef _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_ +#define _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_ + +/* + * Compile time versions of __arch_hweightN() + */ +#define __const_hweight8(w) \ + ( (!!((w) & (1ULL << 0))) + \ + (!!((w) & (1ULL << 1))) + \ + (!!((w) & (1ULL << 2))) + \ + (!!((w) & (1ULL << 3))) + \ + (!!((w) & (1ULL << 4))) + \ + (!!((w) & (1ULL << 5))) + \ + (!!((w) & (1ULL << 6))) + \ + (!!((w) & (1ULL << 7))) ) + +#define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> 8 )) +#define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16)) +#define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32)) + +/* + * Generic interface. + */ +#define hweight8(w) (__builtin_constant_p(w) ? __const_hweight8(w) : __arch_hweight8(w)) +#define hweight16(w) (__builtin_constant_p(w) ? __const_hweight16(w) : __arch_hweight16(w)) +#define hweight32(w) (__builtin_constant_p(w) ? __const_hweight32(w) : __arch_hweight32(w)) +#define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w)) + +/* + * Interface for known constant arguments + */ +#define HWEIGHT8(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight8(w)) +#define HWEIGHT16(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight16(w)) +#define HWEIGHT32(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight32(w)) +#define HWEIGHT64(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight64(w)) + +/* + * Type invariant interface to the compile time constant hweight functions. + */ +#define HWEIGHT(w) HWEIGHT64((u64)w) + +#endif /* _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_ */ diff --git a/include/asm-generic/bitops/hweight.h b/include/asm-generic/bitops/hweight.h index fbbc383771d..a94d6519c7e 100644 --- a/include/asm-generic/bitops/hweight.h +++ b/include/asm-generic/bitops/hweight.h @@ -1,11 +1,7 @@ #ifndef _ASM_GENERIC_BITOPS_HWEIGHT_H_ #define _ASM_GENERIC_BITOPS_HWEIGHT_H_ -#include - -extern unsigned int hweight32(unsigned int w); -extern unsigned int hweight16(unsigned int w); -extern unsigned int hweight8(unsigned int w); -extern unsigned long hweight64(__u64 w); +#include +#include #endif /* _ASM_GENERIC_BITOPS_HWEIGHT_H_ */ diff --git a/include/linux/bitops.h b/include/linux/bitops.h index b7938987923..c55d5bc4ee5 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -47,31 +47,6 @@ static inline unsigned long hweight_long(unsigned long w) return sizeof(w) == 4 ? hweight32(w) : hweight64(w); } -/* - * Clearly slow versions of the hweightN() functions, their benefit is - * of course compile time evaluation of constant arguments. - */ -#define HWEIGHT8(w) \ - ( BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + \ - (!!((w) & (1ULL << 0))) + \ - (!!((w) & (1ULL << 1))) + \ - (!!((w) & (1ULL << 2))) + \ - (!!((w) & (1ULL << 3))) + \ - (!!((w) & (1ULL << 4))) + \ - (!!((w) & (1ULL << 5))) + \ - (!!((w) & (1ULL << 6))) + \ - (!!((w) & (1ULL << 7))) ) - -#define HWEIGHT16(w) (HWEIGHT8(w) + HWEIGHT8((w) >> 8)) -#define HWEIGHT32(w) (HWEIGHT16(w) + HWEIGHT16((w) >> 16)) -#define HWEIGHT64(w) (HWEIGHT32(w) + HWEIGHT32((w) >> 32)) - -/* - * Type invariant version that simply casts things to the - * largest type. - */ -#define HWEIGHT(w) HWEIGHT64((u64)(w)) - /** * rol32 - rotate a 32-bit value left * @word: value to rotate diff --git a/lib/hweight.c b/lib/hweight.c index 63ee4eb1228..a6927e76840 100644 --- a/lib/hweight.c +++ b/lib/hweight.c @@ -9,7 +9,7 @@ * The Hamming Weight of a number is the total number of bits set in it. */ -unsigned int hweight32(unsigned int w) +unsigned int __arch_hweight32(unsigned int w) { #ifdef ARCH_HAS_FAST_MULTIPLIER w -= (w >> 1) & 0x55555555; @@ -24,29 +24,30 @@ unsigned int hweight32(unsigned int w) return (res + (res >> 16)) & 0x000000FF; #endif } -EXPORT_SYMBOL(hweight32); +EXPORT_SYMBOL(__arch_hweight32); -unsigned int hweight16(unsigned int w) +unsigned int __arch_hweight16(unsigned int w) { unsigned int res = w - ((w >> 1) & 0x5555); res = (res & 0x3333) + ((res >> 2) & 0x3333); res = (res + (res >> 4)) & 0x0F0F; return (res + (res >> 8)) & 0x00FF; } -EXPORT_SYMBOL(hweight16); +EXPORT_SYMBOL(__arch_hweight16); -unsigned int hweight8(unsigned int w) +unsigned int __arch_hweight8(unsigned int w) { unsigned int res = w - ((w >> 1) & 0x55); res = (res & 0x33) + ((res >> 2) & 0x33); return (res + (res >> 4)) & 0x0F; } -EXPORT_SYMBOL(hweight8); +EXPORT_SYMBOL(__arch_hweight8); -unsigned long hweight64(__u64 w) +unsigned long __arch_hweight64(__u64 w) { #if BITS_PER_LONG == 32 - return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w); + return __arch_hweight32((unsigned int)(w >> 32)) + + __arch_hweight32((unsigned int)w); #elif BITS_PER_LONG == 64 #ifdef ARCH_HAS_FAST_MULTIPLIER w -= (w >> 1) & 0x5555555555555555ul; @@ -63,4 +64,4 @@ unsigned long hweight64(__u64 w) #endif #endif } -EXPORT_SYMBOL(hweight64); +EXPORT_SYMBOL(__arch_hweight64); -- cgit v1.2.3-70-g09d2 From d61931d89be506372d01a90d1755f6d0a9fafe2d Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 5 Mar 2010 17:34:46 +0100 Subject: x86: Add optimized popcnt variants Add support for the hardware version of the Hamming weight function, popcnt, present in CPUs which advertize it under CPUID, Function 0x0000_0001_ECX[23]. On CPUs which don't support it, we fallback to the default lib/hweight.c sw versions. A synthetic benchmark comparing popcnt with __sw_hweight64 showed almost a 3x speedup on a F10h machine. Signed-off-by: Borislav Petkov LKML-Reference: <20100318112015.GC11152@aftab> Signed-off-by: H. Peter Anvin --- arch/x86/Kconfig | 5 +++ arch/x86/include/asm/alternative.h | 9 +++-- arch/x86/include/asm/arch_hweight.h | 59 +++++++++++++++++++++++++++++++ arch/x86/include/asm/bitops.h | 4 ++- include/asm-generic/bitops/arch_hweight.h | 22 +++++++++--- lib/Makefile | 3 ++ lib/hweight.c | 20 +++++------ scripts/Makefile.lib | 4 +++ 8 files changed, 108 insertions(+), 18 deletions(-) create mode 100644 arch/x86/include/asm/arch_hweight.h (limited to 'include') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0eacb1ffb42..89d8c54cdd3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -238,6 +238,11 @@ config X86_32_LAZY_GS def_bool y depends on X86_32 && !CC_STACKPROTECTOR +config ARCH_HWEIGHT_CFLAGS + string + default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 + default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 + config KTIME_SCALAR def_bool X86_32 source "init/Kconfig" diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index b09ec55650b..67dae51e7fd 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -39,9 +39,6 @@ #define LOCK_PREFIX "" #endif -/* This must be included *after* the definition of LOCK_PREFIX */ -#include - struct alt_instr { u8 *instr; /* original instruction */ u8 *replacement; @@ -95,6 +92,12 @@ static inline int alternatives_text_reserved(void *start, void *end) "663:\n\t" newinstr "\n664:\n" /* replacement */ \ ".previous" +/* + * This must be included *after* the definition of ALTERNATIVE due to + * + */ +#include + /* * Alternative instructions for different CPU types or capabilities. * diff --git a/arch/x86/include/asm/arch_hweight.h b/arch/x86/include/asm/arch_hweight.h new file mode 100644 index 00000000000..d1fc3c219ae --- /dev/null +++ b/arch/x86/include/asm/arch_hweight.h @@ -0,0 +1,59 @@ +#ifndef _ASM_X86_HWEIGHT_H +#define _ASM_X86_HWEIGHT_H + +#ifdef CONFIG_64BIT +/* popcnt %rdi, %rax */ +#define POPCNT ".byte 0xf3,0x48,0x0f,0xb8,0xc7" +#define REG_IN "D" +#define REG_OUT "a" +#else +/* popcnt %eax, %eax */ +#define POPCNT ".byte 0xf3,0x0f,0xb8,0xc0" +#define REG_IN "a" +#define REG_OUT "a" +#endif + +/* + * __sw_hweightXX are called from within the alternatives below + * and callee-clobbered registers need to be taken care of. See + * ARCH_HWEIGHT_CFLAGS in for the respective + * compiler switches. + */ +static inline unsigned int __arch_hweight32(unsigned int w) +{ + unsigned int res = 0; + + asm (ALTERNATIVE("call __sw_hweight32", POPCNT, X86_FEATURE_POPCNT) + : "="REG_OUT (res) + : REG_IN (w)); + + return res; +} + +static inline unsigned int __arch_hweight16(unsigned int w) +{ + return __arch_hweight32(w & 0xffff); +} + +static inline unsigned int __arch_hweight8(unsigned int w) +{ + return __arch_hweight32(w & 0xff); +} + +static inline unsigned long __arch_hweight64(__u64 w) +{ + unsigned long res = 0; + +#ifdef CONFIG_X86_32 + return __arch_hweight32((u32)w) + + __arch_hweight32((u32)(w >> 32)); +#else + asm (ALTERNATIVE("call __sw_hweight64", POPCNT, X86_FEATURE_POPCNT) + : "="REG_OUT (res) + : REG_IN (w)); +#endif /* CONFIG_X86_32 */ + + return res; +} + +#endif diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 02b47a603fc..545776efeb1 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -444,7 +444,9 @@ static inline int fls(int x) #define ARCH_HAS_FAST_MULTIPLIER 1 -#include +#include + +#include #endif /* __KERNEL__ */ diff --git a/include/asm-generic/bitops/arch_hweight.h b/include/asm-generic/bitops/arch_hweight.h index 3a7be842cdc..9a81c1e9436 100644 --- a/include/asm-generic/bitops/arch_hweight.h +++ b/include/asm-generic/bitops/arch_hweight.h @@ -3,9 +3,23 @@ #include -extern unsigned int __arch_hweight32(unsigned int w); -extern unsigned int __arch_hweight16(unsigned int w); -extern unsigned int __arch_hweight8(unsigned int w); -extern unsigned long __arch_hweight64(__u64 w); +inline unsigned int __arch_hweight32(unsigned int w) +{ + return __sw_hweight32(w); +} +inline unsigned int __arch_hweight16(unsigned int w) +{ + return __sw_hweight16(w); +} + +inline unsigned int __arch_hweight8(unsigned int w) +{ + return __sw_hweight8(w); +} + +inline unsigned long __arch_hweight64(__u64 w) +{ + return __sw_hweight64(w); +} #endif /* _ASM_GENERIC_BITOPS_HWEIGHT_H_ */ diff --git a/lib/Makefile b/lib/Makefile index 2e152aed719..abe63a8ad14 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -39,7 +39,10 @@ lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o lib-$(CONFIG_GENERIC_FIND_FIRST_BIT) += find_next_bit.o lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o + +CFLAGS_hweight.o = $(subst $(quote),,$(CONFIG_ARCH_HWEIGHT_CFLAGS)) obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o + obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o obj-$(CONFIG_BTREE) += btree.o obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o diff --git a/lib/hweight.c b/lib/hweight.c index a6927e76840..3c79d50814c 100644 --- a/lib/hweight.c +++ b/lib/hweight.c @@ -9,7 +9,7 @@ * The Hamming Weight of a number is the total number of bits set in it. */ -unsigned int __arch_hweight32(unsigned int w) +unsigned int __sw_hweight32(unsigned int w) { #ifdef ARCH_HAS_FAST_MULTIPLIER w -= (w >> 1) & 0x55555555; @@ -24,30 +24,30 @@ unsigned int __arch_hweight32(unsigned int w) return (res + (res >> 16)) & 0x000000FF; #endif } -EXPORT_SYMBOL(__arch_hweight32); +EXPORT_SYMBOL(__sw_hweight32); -unsigned int __arch_hweight16(unsigned int w) +unsigned int __sw_hweight16(unsigned int w) { unsigned int res = w - ((w >> 1) & 0x5555); res = (res & 0x3333) + ((res >> 2) & 0x3333); res = (res + (res >> 4)) & 0x0F0F; return (res + (res >> 8)) & 0x00FF; } -EXPORT_SYMBOL(__arch_hweight16); +EXPORT_SYMBOL(__sw_hweight16); -unsigned int __arch_hweight8(unsigned int w) +unsigned int __sw_hweight8(unsigned int w) { unsigned int res = w - ((w >> 1) & 0x55); res = (res & 0x33) + ((res >> 2) & 0x33); return (res + (res >> 4)) & 0x0F; } -EXPORT_SYMBOL(__arch_hweight8); +EXPORT_SYMBOL(__sw_hweight8); -unsigned long __arch_hweight64(__u64 w) +unsigned long __sw_hweight64(__u64 w) { #if BITS_PER_LONG == 32 - return __arch_hweight32((unsigned int)(w >> 32)) + - __arch_hweight32((unsigned int)w); + return __sw_hweight32((unsigned int)(w >> 32)) + + __sw_hweight32((unsigned int)w); #elif BITS_PER_LONG == 64 #ifdef ARCH_HAS_FAST_MULTIPLIER w -= (w >> 1) & 0x5555555555555555ul; @@ -64,4 +64,4 @@ unsigned long __arch_hweight64(__u64 w) #endif #endif } -EXPORT_SYMBOL(__arch_hweight64); +EXPORT_SYMBOL(__sw_hweight64); diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index f9bdf264473..cbcd654215e 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -245,3 +245,7 @@ quiet_cmd_lzo = LZO $@ cmd_lzo = (cat $(filter-out FORCE,$^) | \ lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \ (rm -f $@ ; false) + +# misc stuff +# --------------------------------------------------------------------------- +quote:=" -- cgit v1.2.3-70-g09d2 From 6dad2a29646ce3792c40cfc52d77e9b65a7bb143 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 31 Mar 2010 21:56:46 +0200 Subject: cpufreq: Unify sysfs attribute definition macros Multiple modules used to define those which are with identical functionality and were needlessly replicated among the different cpufreq drivers. Push them into the header and remove duplication. Signed-off-by: Borislav Petkov LKML-Reference: <1270065406-1814-7-git-send-email-bp@amd64.org> Reviewed-by: Thomas Renninger Signed-off-by: H. Peter Anvin --- drivers/cpufreq/cpufreq.c | 40 ++++++++++------------------ drivers/cpufreq/cpufreq_conservative.c | 48 ++++++++++++---------------------- drivers/cpufreq/cpufreq_ondemand.c | 40 +++++++++------------------- include/linux/cpufreq.h | 30 +++++++++++++++++++++ 4 files changed, 72 insertions(+), 86 deletions(-) (limited to 'include') diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 2d5d575e889..e02e4174c2c 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -662,32 +662,20 @@ static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); } -#define define_one_ro(_name) \ -static struct freq_attr _name = \ -__ATTR(_name, 0444, show_##_name, NULL) - -#define define_one_ro0400(_name) \ -static struct freq_attr _name = \ -__ATTR(_name, 0400, show_##_name, NULL) - -#define define_one_rw(_name) \ -static struct freq_attr _name = \ -__ATTR(_name, 0644, show_##_name, store_##_name) - -define_one_ro0400(cpuinfo_cur_freq); -define_one_ro(cpuinfo_min_freq); -define_one_ro(cpuinfo_max_freq); -define_one_ro(cpuinfo_transition_latency); -define_one_ro(scaling_available_governors); -define_one_ro(scaling_driver); -define_one_ro(scaling_cur_freq); -define_one_ro(bios_limit); -define_one_ro(related_cpus); -define_one_ro(affected_cpus); -define_one_rw(scaling_min_freq); -define_one_rw(scaling_max_freq); -define_one_rw(scaling_governor); -define_one_rw(scaling_setspeed); +cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); +cpufreq_freq_attr_ro(cpuinfo_min_freq); +cpufreq_freq_attr_ro(cpuinfo_max_freq); +cpufreq_freq_attr_ro(cpuinfo_transition_latency); +cpufreq_freq_attr_ro(scaling_available_governors); +cpufreq_freq_attr_ro(scaling_driver); +cpufreq_freq_attr_ro(scaling_cur_freq); +cpufreq_freq_attr_ro(bios_limit); +cpufreq_freq_attr_ro(related_cpus); +cpufreq_freq_attr_ro(affected_cpus); +cpufreq_freq_attr_rw(scaling_min_freq); +cpufreq_freq_attr_rw(scaling_max_freq); +cpufreq_freq_attr_rw(scaling_governor); +cpufreq_freq_attr_rw(scaling_setspeed); static struct attribute *default_attrs[] = { &cpuinfo_min_freq.attr, diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c index 599a40b25cb..ce5248e0421 100644 --- a/drivers/cpufreq/cpufreq_conservative.c +++ b/drivers/cpufreq/cpufreq_conservative.c @@ -178,12 +178,8 @@ static ssize_t show_sampling_rate_min(struct kobject *kobj, return sprintf(buf, "%u\n", min_sampling_rate); } -#define define_one_ro(_name) \ -static struct global_attr _name = \ -__ATTR(_name, 0444, show_##_name, NULL) - -define_one_ro(sampling_rate_max); -define_one_ro(sampling_rate_min); +define_one_global_ro(sampling_rate_max); +define_one_global_ro(sampling_rate_min); /* cpufreq_conservative Governor Tunables */ #define show_one(file_name, object) \ @@ -221,12 +217,8 @@ show_one_old(freq_step); show_one_old(sampling_rate_min); show_one_old(sampling_rate_max); -#define define_one_ro_old(object, _name) \ -static struct freq_attr object = \ -__ATTR(_name, 0444, show_##_name##_old, NULL) - -define_one_ro_old(sampling_rate_min_old, sampling_rate_min); -define_one_ro_old(sampling_rate_max_old, sampling_rate_max); +cpufreq_freq_attr_ro_old(sampling_rate_min); +cpufreq_freq_attr_ro_old(sampling_rate_max); /*** delete after deprecation time ***/ @@ -364,16 +356,12 @@ static ssize_t store_freq_step(struct kobject *a, struct attribute *b, return count; } -#define define_one_rw(_name) \ -static struct global_attr _name = \ -__ATTR(_name, 0644, show_##_name, store_##_name) - -define_one_rw(sampling_rate); -define_one_rw(sampling_down_factor); -define_one_rw(up_threshold); -define_one_rw(down_threshold); -define_one_rw(ignore_nice_load); -define_one_rw(freq_step); +define_one_global_rw(sampling_rate); +define_one_global_rw(sampling_down_factor); +define_one_global_rw(up_threshold); +define_one_global_rw(down_threshold); +define_one_global_rw(ignore_nice_load); +define_one_global_rw(freq_step); static struct attribute *dbs_attributes[] = { &sampling_rate_max.attr, @@ -409,16 +397,12 @@ write_one_old(down_threshold); write_one_old(ignore_nice_load); write_one_old(freq_step); -#define define_one_rw_old(object, _name) \ -static struct freq_attr object = \ -__ATTR(_name, 0644, show_##_name##_old, store_##_name##_old) - -define_one_rw_old(sampling_rate_old, sampling_rate); -define_one_rw_old(sampling_down_factor_old, sampling_down_factor); -define_one_rw_old(up_threshold_old, up_threshold); -define_one_rw_old(down_threshold_old, down_threshold); -define_one_rw_old(ignore_nice_load_old, ignore_nice_load); -define_one_rw_old(freq_step_old, freq_step); +cpufreq_freq_attr_rw_old(sampling_rate); +cpufreq_freq_attr_rw_old(sampling_down_factor); +cpufreq_freq_attr_rw_old(up_threshold); +cpufreq_freq_attr_rw_old(down_threshold); +cpufreq_freq_attr_rw_old(ignore_nice_load); +cpufreq_freq_attr_rw_old(freq_step); static struct attribute *dbs_attributes_old[] = { &sampling_rate_max_old.attr, diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index bd444dc93cf..c00b25f4d24 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -234,12 +234,8 @@ static ssize_t show_sampling_rate_min(struct kobject *kobj, return sprintf(buf, "%u\n", min_sampling_rate); } -#define define_one_ro(_name) \ -static struct global_attr _name = \ -__ATTR(_name, 0444, show_##_name, NULL) - -define_one_ro(sampling_rate_max); -define_one_ro(sampling_rate_min); +define_one_global_ro(sampling_rate_max); +define_one_global_ro(sampling_rate_min); /* cpufreq_ondemand Governor Tunables */ #define show_one(file_name, object) \ @@ -274,12 +270,8 @@ show_one_old(powersave_bias); show_one_old(sampling_rate_min); show_one_old(sampling_rate_max); -#define define_one_ro_old(object, _name) \ -static struct freq_attr object = \ -__ATTR(_name, 0444, show_##_name##_old, NULL) - -define_one_ro_old(sampling_rate_min_old, sampling_rate_min); -define_one_ro_old(sampling_rate_max_old, sampling_rate_max); +cpufreq_freq_attr_ro_old(sampling_rate_min); +cpufreq_freq_attr_ro_old(sampling_rate_max); /*** delete after deprecation time ***/ @@ -376,14 +368,10 @@ static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b, return count; } -#define define_one_rw(_name) \ -static struct global_attr _name = \ -__ATTR(_name, 0644, show_##_name, store_##_name) - -define_one_rw(sampling_rate); -define_one_rw(up_threshold); -define_one_rw(ignore_nice_load); -define_one_rw(powersave_bias); +define_one_global_rw(sampling_rate); +define_one_global_rw(up_threshold); +define_one_global_rw(ignore_nice_load); +define_one_global_rw(powersave_bias); static struct attribute *dbs_attributes[] = { &sampling_rate_max.attr, @@ -415,14 +403,10 @@ write_one_old(up_threshold); write_one_old(ignore_nice_load); write_one_old(powersave_bias); -#define define_one_rw_old(object, _name) \ -static struct freq_attr object = \ -__ATTR(_name, 0644, show_##_name##_old, store_##_name##_old) - -define_one_rw_old(sampling_rate_old, sampling_rate); -define_one_rw_old(up_threshold_old, up_threshold); -define_one_rw_old(ignore_nice_load_old, ignore_nice_load); -define_one_rw_old(powersave_bias_old, powersave_bias); +cpufreq_freq_attr_rw_old(sampling_rate); +cpufreq_freq_attr_rw_old(up_threshold); +cpufreq_freq_attr_rw_old(ignore_nice_load); +cpufreq_freq_attr_rw_old(powersave_bias); static struct attribute *dbs_attributes_old[] = { &sampling_rate_max_old.attr, diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 4de02b10007..9f15150ce8d 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -278,6 +278,27 @@ struct freq_attr { ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); }; +#define cpufreq_freq_attr_ro(_name) \ +static struct freq_attr _name = \ +__ATTR(_name, 0444, show_##_name, NULL) + +#define cpufreq_freq_attr_ro_perm(_name, _perm) \ +static struct freq_attr _name = \ +__ATTR(_name, _perm, show_##_name, NULL) + +#define cpufreq_freq_attr_ro_old(_name) \ +static struct freq_attr _name##_old = \ +__ATTR(_name, 0444, show_##_name##_old, NULL) + +#define cpufreq_freq_attr_rw(_name) \ +static struct freq_attr _name = \ +__ATTR(_name, 0644, show_##_name, store_##_name) + +#define cpufreq_freq_attr_rw_old(_name) \ +static struct freq_attr _name##_old = \ +__ATTR(_name, 0644, show_##_name##_old, store_##_name##_old) + + struct global_attr { struct attribute attr; ssize_t (*show)(struct kobject *kobj, @@ -286,6 +307,15 @@ struct global_attr { const char *c, size_t count); }; +#define define_one_global_ro(_name) \ +static struct global_attr _name = \ +__ATTR(_name, 0444, show_##_name, NULL) + +#define define_one_global_rw(_name) \ +static struct global_attr _name = \ +__ATTR(_name, 0644, show_##_name, store_##_name) + + /********************************************************************* * CPUFREQ 2.6. INTERFACE * *********************************************************************/ -- cgit v1.2.3-70-g09d2 From 76e1d9047e4edefb8ada20aa90d5762306082bd6 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 5 Apr 2010 15:35:57 +0200 Subject: perf: Store active software events in a hashlist Each time a software event triggers, we need to walk through the entire list of events from the current cpu and task contexts to retrieve a running perf event that matches. We also need to check a matching perf event is actually counting. This walk is wasteful and makes the event fast path scaling down with a growing number of events running on the same contexts. To solve this, we store the running perf events in a hashlist to get an immediate access to them against their type:event_id when they trigger. v2: - Fix SWEVENT_HLIST_SIZE definition (and re-learn some basic maths along the way) - Only allocate hlist for online cpus, but keep track of the refcount on offline possible cpus too, so that we allocate it if needed when it becomes online. - Drop the kref use as it's not adapted to our tricks anymore. v3: - Fix bad refcount check (address instead of value). Thanks to Eric Dumazet who spotted this. - While exiting cpu, move the hlist release out of the IPI path to lock the hlist mutex sanely. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Ingo Molnar --- include/linux/perf_event.h | 12 +++ kernel/perf_event.c | 246 +++++++++++++++++++++++++++++++++------------ 2 files changed, 195 insertions(+), 63 deletions(-) (limited to 'include') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 6e96cc8225d..bf896d0b2e9 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -589,6 +589,14 @@ enum perf_group_flag { PERF_GROUP_SOFTWARE = 0x1, }; +#define SWEVENT_HLIST_BITS 8 +#define SWEVENT_HLIST_SIZE (1 << SWEVENT_HLIST_BITS) + +struct swevent_hlist { + struct hlist_head heads[SWEVENT_HLIST_SIZE]; + struct rcu_head rcu_head; +}; + /** * struct perf_event - performance event kernel representation: */ @@ -597,6 +605,7 @@ struct perf_event { struct list_head group_entry; struct list_head event_entry; struct list_head sibling_list; + struct hlist_node hlist_entry; int nr_siblings; int group_flags; struct perf_event *group_leader; @@ -744,6 +753,9 @@ struct perf_cpu_context { int active_oncpu; int max_pertask; int exclusive; + struct swevent_hlist *swevent_hlist; + struct mutex hlist_mutex; + int hlist_refcount; /* * Recursion avoidance: diff --git a/kernel/perf_event.c b/kernel/perf_event.c index fcf42dcd608..9efdfe5b8d3 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -3966,36 +3967,6 @@ static void perf_swevent_add(struct perf_event *event, u64 nr, perf_swevent_overflow(event, 0, nmi, data, regs); } -static int perf_swevent_is_counting(struct perf_event *event) -{ - /* - * The event is active, we're good! - */ - if (event->state == PERF_EVENT_STATE_ACTIVE) - return 1; - - /* - * The event is off/error, not counting. - */ - if (event->state != PERF_EVENT_STATE_INACTIVE) - return 0; - - /* - * The event is inactive, if the context is active - * we're part of a group that didn't make it on the 'pmu', - * not counting. - */ - if (event->ctx->is_active) - return 0; - - /* - * We're inactive and the context is too, this means the - * task is scheduled out, we're counting events that happen - * to us, like migration events. - */ - return 1; -} - static int perf_tp_event_match(struct perf_event *event, struct perf_sample_data *data); @@ -4019,12 +3990,6 @@ static int perf_swevent_match(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs) { - if (event->cpu != -1 && event->cpu != smp_processor_id()) - return 0; - - if (!perf_swevent_is_counting(event)) - return 0; - if (event->attr.type != type) return 0; @@ -4041,18 +4006,53 @@ static int perf_swevent_match(struct perf_event *event, return 1; } -static void perf_swevent_ctx_event(struct perf_event_context *ctx, - enum perf_type_id type, - u32 event_id, u64 nr, int nmi, - struct perf_sample_data *data, - struct pt_regs *regs) +static inline u64 swevent_hash(u64 type, u32 event_id) +{ + u64 val = event_id | (type << 32); + + return hash_64(val, SWEVENT_HLIST_BITS); +} + +static struct hlist_head * +find_swevent_head(struct perf_cpu_context *ctx, u64 type, u32 event_id) +{ + u64 hash; + struct swevent_hlist *hlist; + + hash = swevent_hash(type, event_id); + + hlist = rcu_dereference(ctx->swevent_hlist); + if (!hlist) + return NULL; + + return &hlist->heads[hash]; +} + +static void do_perf_sw_event(enum perf_type_id type, u32 event_id, + u64 nr, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) { + struct perf_cpu_context *cpuctx; struct perf_event *event; + struct hlist_node *node; + struct hlist_head *head; - list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { + cpuctx = &__get_cpu_var(perf_cpu_context); + + rcu_read_lock(); + + head = find_swevent_head(cpuctx, type, event_id); + + if (!head) + goto end; + + hlist_for_each_entry_rcu(event, node, head, hlist_entry) { if (perf_swevent_match(event, type, event_id, data, regs)) perf_swevent_add(event, nr, nmi, data, regs); } +end: + rcu_read_unlock(); } int perf_swevent_get_recursion_context(void) @@ -4090,27 +4090,6 @@ void perf_swevent_put_recursion_context(int rctx) } EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context); -static void do_perf_sw_event(enum perf_type_id type, u32 event_id, - u64 nr, int nmi, - struct perf_sample_data *data, - struct pt_regs *regs) -{ - struct perf_cpu_context *cpuctx; - struct perf_event_context *ctx; - - cpuctx = &__get_cpu_var(perf_cpu_context); - rcu_read_lock(); - perf_swevent_ctx_event(&cpuctx->ctx, type, event_id, - nr, nmi, data, regs); - /* - * doesn't really matter which of the child contexts the - * events ends up in. - */ - ctx = rcu_dereference(current->perf_event_ctxp); - if (ctx) - perf_swevent_ctx_event(ctx, type, event_id, nr, nmi, data, regs); - rcu_read_unlock(); -} void __perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr) @@ -4136,16 +4115,28 @@ static void perf_swevent_read(struct perf_event *event) static int perf_swevent_enable(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; + struct perf_cpu_context *cpuctx; + struct hlist_head *head; + + cpuctx = &__get_cpu_var(perf_cpu_context); if (hwc->sample_period) { hwc->last_period = hwc->sample_period; perf_swevent_set_period(event); } + + head = find_swevent_head(cpuctx, event->attr.type, event->attr.config); + if (WARN_ON_ONCE(!head)) + return -EINVAL; + + hlist_add_head_rcu(&event->hlist_entry, head); + return 0; } static void perf_swevent_disable(struct perf_event *event) { + hlist_del_rcu(&event->hlist_entry); } static const struct pmu perf_ops_generic = { @@ -4359,13 +4350,115 @@ static int perf_tp_event_match(struct perf_event *event, return 0; } +static void swevent_hlist_release_rcu(struct rcu_head *rcu_head) +{ + struct swevent_hlist *hlist; + + hlist = container_of(rcu_head, struct swevent_hlist, rcu_head); + kfree(hlist); +} + +static void swevent_hlist_release(struct perf_cpu_context *cpuctx) +{ + struct swevent_hlist *hlist; + + if (!cpuctx->swevent_hlist) + return; + + hlist = cpuctx->swevent_hlist; + rcu_assign_pointer(cpuctx->swevent_hlist, NULL); + call_rcu(&hlist->rcu_head, swevent_hlist_release_rcu); +} + +static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) +{ + struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + + mutex_lock(&cpuctx->hlist_mutex); + + if (!--cpuctx->hlist_refcount) + swevent_hlist_release(cpuctx); + + mutex_unlock(&cpuctx->hlist_mutex); +} + +static void swevent_hlist_put(struct perf_event *event) +{ + int cpu; + + if (event->cpu != -1) { + swevent_hlist_put_cpu(event, event->cpu); + return; + } + + for_each_possible_cpu(cpu) + swevent_hlist_put_cpu(event, cpu); +} + +static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) +{ + struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + int err = 0; + + mutex_lock(&cpuctx->hlist_mutex); + + if (!cpuctx->swevent_hlist && cpu_online(cpu)) { + struct swevent_hlist *hlist; + + hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); + if (!hlist) { + err = -ENOMEM; + goto exit; + } + rcu_assign_pointer(cpuctx->swevent_hlist, hlist); + } + cpuctx->hlist_refcount++; + exit: + mutex_unlock(&cpuctx->hlist_mutex); + + return err; +} + +static int swevent_hlist_get(struct perf_event *event) +{ + int err; + int cpu, failed_cpu; + + if (event->cpu != -1) + return swevent_hlist_get_cpu(event, event->cpu); + + get_online_cpus(); + for_each_possible_cpu(cpu) { + err = swevent_hlist_get_cpu(event, cpu); + if (err) { + failed_cpu = cpu; + goto fail; + } + } + put_online_cpus(); + + return 0; + fail: + for_each_possible_cpu(cpu) { + if (cpu == failed_cpu) + break; + swevent_hlist_put_cpu(event, cpu); + } + + put_online_cpus(); + return err; +} + static void tp_perf_event_destroy(struct perf_event *event) { perf_trace_disable(event->attr.config); + swevent_hlist_put(event); } static const struct pmu *tp_perf_event_init(struct perf_event *event) { + int err; + /* * Raw tracepoint data is a severe data leak, only allow root to * have these. @@ -4379,6 +4472,11 @@ static const struct pmu *tp_perf_event_init(struct perf_event *event) return NULL; event->destroy = tp_perf_event_destroy; + err = swevent_hlist_get(event); + if (err) { + perf_trace_disable(event->attr.config); + return ERR_PTR(err); + } return &perf_ops_generic; } @@ -4479,6 +4577,7 @@ static void sw_perf_event_destroy(struct perf_event *event) WARN_ON(event->parent); atomic_dec(&perf_swevent_enabled[event_id]); + swevent_hlist_put(event); } static const struct pmu *sw_perf_event_init(struct perf_event *event) @@ -4517,6 +4616,12 @@ static const struct pmu *sw_perf_event_init(struct perf_event *event) case PERF_COUNT_SW_ALIGNMENT_FAULTS: case PERF_COUNT_SW_EMULATION_FAULTS: if (!event->parent) { + int err; + + err = swevent_hlist_get(event); + if (err) + return ERR_PTR(err); + atomic_inc(&perf_swevent_enabled[event_id]); event->destroy = sw_perf_event_destroy; } @@ -5389,6 +5494,7 @@ static void __init perf_event_init_all_cpus(void) for_each_possible_cpu(cpu) { cpuctx = &per_cpu(perf_cpu_context, cpu); + mutex_init(&cpuctx->hlist_mutex); __perf_event_init_context(&cpuctx->ctx, NULL); } } @@ -5402,6 +5508,16 @@ static void __cpuinit perf_event_init_cpu(int cpu) spin_lock(&perf_resource_lock); cpuctx->max_pertask = perf_max_events - perf_reserved_percpu; spin_unlock(&perf_resource_lock); + + mutex_lock(&cpuctx->hlist_mutex); + if (cpuctx->hlist_refcount > 0) { + struct swevent_hlist *hlist; + + hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); + WARN_ON_ONCE(!hlist); + rcu_assign_pointer(cpuctx->swevent_hlist, hlist); + } + mutex_unlock(&cpuctx->hlist_mutex); } #ifdef CONFIG_HOTPLUG_CPU @@ -5421,6 +5537,10 @@ static void perf_event_exit_cpu(int cpu) struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); struct perf_event_context *ctx = &cpuctx->ctx; + mutex_lock(&cpuctx->hlist_mutex); + swevent_hlist_release(cpuctx); + mutex_unlock(&cpuctx->hlist_mutex); + mutex_lock(&ctx->mutex); smp_call_function_single(cpu, __perf_event_exit_cpu, NULL, 1); mutex_unlock(&ctx->mutex); -- cgit v1.2.3-70-g09d2 From 39447b386c846bbf1c56f6403c5282837486200f Mon Sep 17 00:00:00 2001 From: "Zhang, Yanmin" Date: Mon, 19 Apr 2010 13:32:41 +0800 Subject: perf: Enhance perf to allow for guest statistic collection from host Below patch introduces perf_guest_info_callbacks and related register/unregister functions. Add more PERF_RECORD_MISC_XXX bits meaning guest kernel and guest user space. Signed-off-by: Zhang Yanmin Signed-off-by: Avi Kivity --- arch/x86/include/asm/perf_event.h | 15 ++++----------- arch/x86/kernel/cpu/perf_event.c | 31 +++++++++++++++++++++++++++++++ include/linux/perf_event.h | 21 ++++++++++++++++++++- kernel/perf_event.c | 23 ++++++++++++++++++++++- 4 files changed, 77 insertions(+), 13 deletions(-) (limited to 'include') diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index f6d43dbfd8e..254883d0c7e 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -135,17 +135,10 @@ extern void perf_events_lapic_init(void); */ #define PERF_EFLAGS_EXACT (1UL << 3) -#define perf_misc_flags(regs) \ -({ int misc = 0; \ - if (user_mode(regs)) \ - misc |= PERF_RECORD_MISC_USER; \ - else \ - misc |= PERF_RECORD_MISC_KERNEL; \ - if (regs->flags & PERF_EFLAGS_EXACT) \ - misc |= PERF_RECORD_MISC_EXACT; \ - misc; }) - -#define perf_instruction_pointer(regs) ((regs)->ip) +struct pt_regs; +extern unsigned long perf_instruction_pointer(struct pt_regs *regs); +extern unsigned long perf_misc_flags(struct pt_regs *regs); +#define perf_misc_flags(regs) perf_misc_flags(regs) #else static inline void init_hw_perf_events(void) { } diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 626154a9f53..2ea78abf69d 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1720,6 +1720,11 @@ struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) { struct perf_callchain_entry *entry; + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { + /* TODO: We don't support guest os callchain now */ + return NULL; + } + if (in_nmi()) entry = &__get_cpu_var(pmc_nmi_entry); else @@ -1743,3 +1748,29 @@ void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int ski regs->cs = __KERNEL_CS; local_save_flags(regs->flags); } + +unsigned long perf_instruction_pointer(struct pt_regs *regs) +{ + unsigned long ip; + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) + ip = perf_guest_cbs->get_guest_ip(); + else + ip = instruction_pointer(regs); + return ip; +} + +unsigned long perf_misc_flags(struct pt_regs *regs) +{ + int misc = 0; + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { + misc |= perf_guest_cbs->is_user_mode() ? + PERF_RECORD_MISC_GUEST_USER : + PERF_RECORD_MISC_GUEST_KERNEL; + } else + misc |= user_mode(regs) ? PERF_RECORD_MISC_USER : + PERF_RECORD_MISC_KERNEL; + if (regs->flags & PERF_EFLAGS_EXACT) + misc |= PERF_RECORD_MISC_EXACT; + + return misc; +} diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index bf896d0b2e9..24de5f181a4 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -288,11 +288,13 @@ struct perf_event_mmap_page { __u64 data_tail; /* user-space written tail */ }; -#define PERF_RECORD_MISC_CPUMODE_MASK (3 << 0) +#define PERF_RECORD_MISC_CPUMODE_MASK (7 << 0) #define PERF_RECORD_MISC_CPUMODE_UNKNOWN (0 << 0) #define PERF_RECORD_MISC_KERNEL (1 << 0) #define PERF_RECORD_MISC_USER (2 << 0) #define PERF_RECORD_MISC_HYPERVISOR (3 << 0) +#define PERF_RECORD_MISC_GUEST_KERNEL (4 << 0) +#define PERF_RECORD_MISC_GUEST_USER (5 << 0) #define PERF_RECORD_MISC_EXACT (1 << 14) /* @@ -446,6 +448,12 @@ enum perf_callchain_context { # include #endif +struct perf_guest_info_callbacks { + int (*is_in_guest) (void); + int (*is_user_mode) (void); + unsigned long (*get_guest_ip) (void); +}; + #ifdef CONFIG_HAVE_HW_BREAKPOINT #include #endif @@ -932,6 +940,12 @@ static inline void perf_event_mmap(struct vm_area_struct *vma) __perf_event_mmap(vma); } +extern struct perf_guest_info_callbacks *perf_guest_cbs; +extern int perf_register_guest_info_callbacks( + struct perf_guest_info_callbacks *); +extern int perf_unregister_guest_info_callbacks( + struct perf_guest_info_callbacks *); + extern void perf_event_comm(struct task_struct *tsk); extern void perf_event_fork(struct task_struct *tsk); @@ -1001,6 +1015,11 @@ perf_sw_event(u32 event_id, u64 nr, int nmi, static inline void perf_bp_event(struct perf_event *event, void *data) { } +static inline int perf_register_guest_info_callbacks +(struct perf_guest_info_callbacks *) {return 0; } +static inline int perf_unregister_guest_info_callbacks +(struct perf_guest_info_callbacks *) {return 0; } + static inline void perf_event_mmap(struct vm_area_struct *vma) { } static inline void perf_event_comm(struct task_struct *tsk) { } static inline void perf_event_fork(struct task_struct *tsk) { } diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 07b7a435bf0..9dbe8cdaf14 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -2797,6 +2797,27 @@ void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int ski } +/* + * We assume there is only KVM supporting the callbacks. + * Later on, we might change it to a list if there is + * another virtualization implementation supporting the callbacks. + */ +struct perf_guest_info_callbacks *perf_guest_cbs; + +int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) +{ + perf_guest_cbs = cbs; + return 0; +} +EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); + +int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) +{ + perf_guest_cbs = NULL; + return 0; +} +EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); + /* * Output */ @@ -3749,7 +3770,7 @@ void __perf_event_mmap(struct vm_area_struct *vma) .event_id = { .header = { .type = PERF_RECORD_MMAP, - .misc = 0, + .misc = PERF_RECORD_MISC_USER, /* .size */ }, /* .pid */ -- cgit v1.2.3-70-g09d2 From dcf46b9443ad48a227a61713adea001228925adf Mon Sep 17 00:00:00 2001 From: "Zhang, Yanmin" Date: Tue, 20 Apr 2010 10:13:58 +0800 Subject: perf & kvm: Clean up some of the guest profiling callback API details Fix some build bug and programming style issues: - use valid C - fix up various style details Signed-off-by: Zhang Yanmin Cc: Avi Kivity Cc: Peter Zijlstra Cc: Sheng Yang Cc: Marcelo Tosatti Cc: oerg Roedel Cc: Jes Sorensen Cc: Gleb Natapov Cc: Zachary Amsden Cc: zhiteng.huang@intel.com Cc: tim.c.chen@intel.com Cc: Arnaldo Carvalho de Melo LKML-Reference: <1271729638.2078.624.camel@ymzhang.sh.intel.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.c | 20 ++++++++++++++------ arch/x86/kvm/x86.c | 4 ++++ include/linux/perf_event.h | 10 ++++------ 3 files changed, 22 insertions(+), 12 deletions(-) (limited to 'include') diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 2ea78abf69d..7de70613e6c 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1752,23 +1752,31 @@ void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int ski unsigned long perf_instruction_pointer(struct pt_regs *regs) { unsigned long ip; + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) ip = perf_guest_cbs->get_guest_ip(); else ip = instruction_pointer(regs); + return ip; } unsigned long perf_misc_flags(struct pt_regs *regs) { int misc = 0; + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { - misc |= perf_guest_cbs->is_user_mode() ? - PERF_RECORD_MISC_GUEST_USER : - PERF_RECORD_MISC_GUEST_KERNEL; - } else - misc |= user_mode(regs) ? PERF_RECORD_MISC_USER : - PERF_RECORD_MISC_KERNEL; + if (perf_guest_cbs->is_user_mode()) + misc |= PERF_RECORD_MISC_GUEST_USER; + else + misc |= PERF_RECORD_MISC_GUEST_KERNEL; + } else { + if (user_mode(regs)) + misc |= PERF_RECORD_MISC_USER; + else + misc |= PERF_RECORD_MISC_KERNEL; + } + if (regs->flags & PERF_EFLAGS_EXACT) misc |= PERF_RECORD_MISC_EXACT; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c3a33b2bb16..21b9b6aa3e8 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3776,16 +3776,20 @@ static int kvm_is_in_guest(void) static int kvm_is_user_mode(void) { int user_mode = 3; + if (percpu_read(current_vcpu)) user_mode = kvm_x86_ops->get_cpl(percpu_read(current_vcpu)); + return user_mode != 0; } static unsigned long kvm_get_guest_ip(void) { unsigned long ip = 0; + if (percpu_read(current_vcpu)) ip = kvm_rip_read(percpu_read(current_vcpu)); + return ip; } diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 24de5f181a4..ace31fbac51 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -941,10 +941,8 @@ static inline void perf_event_mmap(struct vm_area_struct *vma) } extern struct perf_guest_info_callbacks *perf_guest_cbs; -extern int perf_register_guest_info_callbacks( - struct perf_guest_info_callbacks *); -extern int perf_unregister_guest_info_callbacks( - struct perf_guest_info_callbacks *); +extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); +extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); extern void perf_event_comm(struct task_struct *tsk); extern void perf_event_fork(struct task_struct *tsk); @@ -1016,9 +1014,9 @@ static inline void perf_bp_event(struct perf_event *event, void *data) { } static inline int perf_register_guest_info_callbacks -(struct perf_guest_info_callbacks *) {return 0; } +(struct perf_guest_info_callbacks *callbacks) { return 0; } static inline int perf_unregister_guest_info_callbacks -(struct perf_guest_info_callbacks *) {return 0; } +(struct perf_guest_info_callbacks *callbacks) { return 0; } static inline void perf_event_mmap(struct vm_area_struct *vma) { } static inline void perf_event_comm(struct task_struct *tsk) { } -- cgit v1.2.3-70-g09d2 From cecbca96da387428e220e307a9c945e37e2f4d9e Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sun, 18 Apr 2010 19:08:41 +0200 Subject: tracing: Dump either the oops's cpu source or all cpus buffers The ftrace_dump_on_oops kernel parameter, sysctl and sysrq let one dump every cpu buffers when an oops or panic happens. It's nice when you have few cpus but it may take ages if have many, plus you miss the real origin of the problem in all the cpu traces. Sometimes, all you need is to dump the cpu buffer that triggered the opps, most of the time it is our main interest. This patch modifies ftrace_dump_on_oops to handle this choice. The ftrace_dump_on_oops kernel parameter, when it comes alone, has the same behaviour than before. But ftrace_dump_on_oops=orig_cpu will only dump the buffer of the cpu that oops'ed. Similarly, sysctl kernel.ftrace_dump_on_oops=1 and echo 1 > /proc/sys/kernel/ftrace_dump_on_oops keep their previous behaviour. But setting 2 jumps into cpu origin dump mode. v2: Fix double setup v3: Fix spelling issues reported by Randy Dunlap v4: Also update __ftrace_dump in the selftests Signed-off-by: Frederic Weisbecker Acked-by: David S. Miller Acked-by: Steven Rostedt Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Li Zefan Cc: Lai Jiangshan --- Documentation/kernel-parameters.txt | 6 ++++- Documentation/trace/ftrace.txt | 6 +++-- drivers/char/sysrq.c | 2 +- include/linux/ftrace.h | 4 ++- include/linux/kernel.h | 11 ++++++-- kernel/trace/trace.c | 51 ++++++++++++++++++++++++++++--------- kernel/trace/trace_selftest.c | 5 ++-- 7 files changed, 64 insertions(+), 21 deletions(-) (limited to 'include') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index e4cbca58536..ab67b33300f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -789,8 +789,12 @@ and is between 256 and 4096 characters. It is defined in the file as early as possible in order to facilitate early boot debugging. - ftrace_dump_on_oops + ftrace_dump_on_oops[=orig_cpu] [FTRACE] will dump the trace buffers on oops. + If no parameter is passed, ftrace will dump + buffers of all CPUs, but if you pass orig_cpu, it will + dump only the buffer of the CPU that triggered the + oops. ftrace_filter=[function-list] [FTRACE] Limit the functions traced by the function diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 03485bfbd79..52011815c90 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -1337,12 +1337,14 @@ ftrace_dump_on_oops must be set. To set ftrace_dump_on_oops, one can either use the sysctl function or set it via the proc system interface. - sysctl kernel.ftrace_dump_on_oops=1 + sysctl kernel.ftrace_dump_on_oops=n or - echo 1 > /proc/sys/kernel/ftrace_dump_on_oops + echo n > /proc/sys/kernel/ftrace_dump_on_oops +If n = 1, ftrace will dump buffers of all CPUs, if n = 2 ftrace will +only dump the buffer of the CPU that triggered the oops. Here's an example of such a dump after a null pointer dereference in a kernel module: diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c index 59de2525d30..d4e8b213a46 100644 --- a/drivers/char/sysrq.c +++ b/drivers/char/sysrq.c @@ -289,7 +289,7 @@ static struct sysrq_key_op sysrq_showstate_blocked_op = { static void sysrq_ftrace_dump(int key, struct tty_struct *tty) { - ftrace_dump(); + ftrace_dump(DUMP_ALL); } static struct sysrq_key_op sysrq_ftrace_dump_op = { .handler = sysrq_ftrace_dump, diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 01e6adea07e..ea5b1aae0e8 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -492,7 +492,9 @@ static inline int test_tsk_trace_graph(struct task_struct *tsk) return tsk->trace & TSK_TRACE_FL_GRAPH; } -extern int ftrace_dump_on_oops; +enum ftrace_dump_mode; + +extern enum ftrace_dump_mode ftrace_dump_on_oops; #ifdef CONFIG_PREEMPT #define INIT_TRACE_RECURSION .trace_recursion = 0, diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 9365227dbaf..9fb1c129903 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -490,6 +490,13 @@ static inline void tracing_off(void) { } static inline void tracing_off_permanent(void) { } static inline int tracing_is_on(void) { return 0; } #endif + +enum ftrace_dump_mode { + DUMP_NONE, + DUMP_ALL, + DUMP_ORIG, +}; + #ifdef CONFIG_TRACING extern void tracing_start(void); extern void tracing_stop(void); @@ -571,7 +578,7 @@ __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); extern int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); -extern void ftrace_dump(void); +extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); #else static inline void ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { } @@ -592,7 +599,7 @@ ftrace_vprintk(const char *fmt, va_list ap) { return 0; } -static inline void ftrace_dump(void) { } +static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } #endif /* CONFIG_TRACING */ /* diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bed83cab6da..7b516c7ef9a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -117,9 +117,12 @@ static cpumask_var_t __read_mostly tracing_buffer_mask; * * It is default off, but you can enable it with either specifying * "ftrace_dump_on_oops" in the kernel command line, or setting - * /proc/sys/kernel/ftrace_dump_on_oops to true. + * /proc/sys/kernel/ftrace_dump_on_oops + * Set 1 if you want to dump buffers of all CPUs + * Set 2 if you want to dump the buffer of the CPU that triggered oops */ -int ftrace_dump_on_oops; + +enum ftrace_dump_mode ftrace_dump_on_oops; static int tracing_set_tracer(const char *buf); @@ -139,8 +142,17 @@ __setup("ftrace=", set_cmdline_ftrace); static int __init set_ftrace_dump_on_oops(char *str) { - ftrace_dump_on_oops = 1; - return 1; + if (*str++ != '=' || !*str) { + ftrace_dump_on_oops = DUMP_ALL; + return 1; + } + + if (!strcmp("orig_cpu", str)) { + ftrace_dump_on_oops = DUMP_ORIG; + return 1; + } + + return 0; } __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); @@ -4338,7 +4350,7 @@ static int trace_panic_handler(struct notifier_block *this, unsigned long event, void *unused) { if (ftrace_dump_on_oops) - ftrace_dump(); + ftrace_dump(ftrace_dump_on_oops); return NOTIFY_OK; } @@ -4355,7 +4367,7 @@ static int trace_die_handler(struct notifier_block *self, switch (val) { case DIE_OOPS: if (ftrace_dump_on_oops) - ftrace_dump(); + ftrace_dump(ftrace_dump_on_oops); break; default: break; @@ -4396,7 +4408,8 @@ trace_printk_seq(struct trace_seq *s) trace_seq_init(s); } -static void __ftrace_dump(bool disable_tracing) +static void +__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) { static arch_spinlock_t ftrace_dump_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; @@ -4429,12 +4442,25 @@ static void __ftrace_dump(bool disable_tracing) /* don't look at user memory in panic mode */ trace_flags &= ~TRACE_ITER_SYM_USEROBJ; - printk(KERN_TRACE "Dumping ftrace buffer:\n"); - /* Simulate the iterator */ iter.tr = &global_trace; iter.trace = current_trace; - iter.cpu_file = TRACE_PIPE_ALL_CPU; + + switch (oops_dump_mode) { + case DUMP_ALL: + iter.cpu_file = TRACE_PIPE_ALL_CPU; + break; + case DUMP_ORIG: + iter.cpu_file = raw_smp_processor_id(); + break; + case DUMP_NONE: + goto out_enable; + default: + printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n"); + iter.cpu_file = TRACE_PIPE_ALL_CPU; + } + + printk(KERN_TRACE "Dumping ftrace buffer:\n"); /* * We need to stop all tracing on all CPUS to read the @@ -4473,6 +4499,7 @@ static void __ftrace_dump(bool disable_tracing) else printk(KERN_TRACE "---------------------------------\n"); + out_enable: /* Re-enable tracing if requested */ if (!disable_tracing) { trace_flags |= old_userobj; @@ -4489,9 +4516,9 @@ static void __ftrace_dump(bool disable_tracing) } /* By default: disable tracing after the dump */ -void ftrace_dump(void) +void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { - __ftrace_dump(true); + __ftrace_dump(true, oops_dump_mode); } __init static int tracer_alloc_buffers(void) diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 9398034f814..6a9d36ddfcf 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -256,7 +256,8 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) /* Maximum number of functions to trace before diagnosing a hang */ #define GRAPH_MAX_FUNC_TEST 100000000 -static void __ftrace_dump(bool disable_tracing); +static void +__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode); static unsigned int graph_hang_thresh; /* Wrap the real function entry probe to avoid possible hanging */ @@ -267,7 +268,7 @@ static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace) ftrace_graph_stop(); printk(KERN_WARNING "BUG: Function graph tracer hang!\n"); if (ftrace_dump_on_oops) - __ftrace_dump(false); + __ftrace_dump(false, DUMP_ALL); return 0; } -- cgit v1.2.3-70-g09d2 From 669c55e9f99b90e46eaa0f98a67ec53d46dc969a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 16 Apr 2010 14:59:29 +0200 Subject: sched: Pre-compute cpumask_weight(sched_domain_span(sd)) Dave reported that his large SPARC machines spend lots of time in hweight64(), try and optimize some of those needless cpumask_weight() invocations (esp. with the large offstack cpumasks these are very expensive indeed). Reported-by: David Miller Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- include/linux/sched.h | 1 + kernel/sched.c | 3 +++ kernel/sched_fair.c | 12 +++++------- 3 files changed, 9 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index e3e900f318d..dfea40574b2 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -960,6 +960,7 @@ struct sched_domain { char *name; #endif + unsigned int span_weight; /* * Span of all CPUs in this domain. * diff --git a/kernel/sched.c b/kernel/sched.c index 0cc913a8554..4956ed09283 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6271,6 +6271,9 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) struct rq *rq = cpu_rq(cpu); struct sched_domain *tmp; + for (tmp = sd; tmp; tmp = tmp->parent) + tmp->span_weight = cpumask_weight(sched_domain_span(tmp)); + /* Remove the sched domains which do not contribute to scheduling. */ for (tmp = sd; tmp; ) { struct sched_domain *parent = tmp->parent; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 88d3053ac7c..0a413c7e3ab 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1508,9 +1508,7 @@ select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_ * Pick the largest domain to update shares over */ tmp = sd; - if (affine_sd && (!tmp || - cpumask_weight(sched_domain_span(affine_sd)) > - cpumask_weight(sched_domain_span(sd)))) + if (affine_sd && (!tmp || affine_sd->span_weight > sd->span_weight)) tmp = affine_sd; if (tmp) { @@ -1554,10 +1552,10 @@ select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_ /* Now try balancing at a lower domain level of new_cpu */ cpu = new_cpu; - weight = cpumask_weight(sched_domain_span(sd)); + weight = sd->span_weight; sd = NULL; for_each_domain(cpu, tmp) { - if (weight <= cpumask_weight(sched_domain_span(tmp))) + if (weight <= tmp->span_weight) break; if (tmp->flags & sd_flag) sd = tmp; @@ -2243,7 +2241,7 @@ unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu) unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu) { - unsigned long weight = cpumask_weight(sched_domain_span(sd)); + unsigned long weight = sd->span_weight; unsigned long smt_gain = sd->smt_gain; smt_gain /= weight; @@ -2276,7 +2274,7 @@ unsigned long scale_rt_power(int cpu) static void update_cpu_power(struct sched_domain *sd, int cpu) { - unsigned long weight = cpumask_weight(sched_domain_span(sd)); + unsigned long weight = sd->span_weight; unsigned long power = SCHED_LOAD_SCALE; struct sched_group *sdg = sd->groups; -- cgit v1.2.3-70-g09d2 From 62b915f1060996a8e1f69be50e3b8e9e43b710cb Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Fri, 2 Apr 2010 19:01:22 +0200 Subject: tracing: Add graph output support for irqsoff tracer Add function graph output to irqsoff tracer. The graph output is enabled by setting new 'display-graph' trace option. Signed-off-by: Jiri Olsa LKML-Reference: <1270227683-14631-4-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt --- include/linux/ftrace.h | 15 +- kernel/trace/trace.c | 35 +++-- kernel/trace/trace.h | 21 +++ kernel/trace/trace_functions_graph.c | 15 +- kernel/trace/trace_irqsoff.c | 271 +++++++++++++++++++++++++++++++++-- 5 files changed, 324 insertions(+), 33 deletions(-) (limited to 'include') diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index ea5b1aae0e8..8415a522f43 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -352,6 +352,10 @@ struct ftrace_graph_ret { int depth; }; +/* Type of the callback handlers for tracing function graph*/ +typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ +typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ + #ifdef CONFIG_FUNCTION_GRAPH_TRACER /* for init task */ @@ -400,10 +404,6 @@ extern char __irqentry_text_end[]; #define FTRACE_RETFUNC_DEPTH 50 #define FTRACE_RETSTACK_ALLOC_SIZE 32 -/* Type of the callback handlers for tracing function graph*/ -typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ -typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ - extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, trace_func_graph_ent_t entryfunc); @@ -441,6 +441,13 @@ static inline void unpause_graph_tracing(void) static inline void ftrace_graph_init_task(struct task_struct *t) { } static inline void ftrace_graph_exit_task(struct task_struct *t) { } +static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, + trace_func_graph_ent_t entryfunc) +{ + return -1; +} +static inline void unregister_ftrace_graph(void) { } + static inline int task_curr_ret_stack(struct task_struct *tsk) { return -1; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7b516c7ef9a..8b9ba41ec14 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1808,7 +1808,7 @@ static void print_func_help_header(struct seq_file *m) } -static void +void print_trace_header(struct seq_file *m, struct trace_iterator *iter) { unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); @@ -2017,7 +2017,7 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter) return event ? event->binary(iter, 0) : TRACE_TYPE_HANDLED; } -static int trace_empty(struct trace_iterator *iter) +int trace_empty(struct trace_iterator *iter) { int cpu; @@ -2084,6 +2084,23 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter) return print_trace_fmt(iter); } +void trace_default_header(struct seq_file *m) +{ + struct trace_iterator *iter = m->private; + + if (iter->iter_flags & TRACE_FILE_LAT_FMT) { + /* print nothing if the buffers are empty */ + if (trace_empty(iter)) + return; + print_trace_header(m, iter); + if (!(trace_flags & TRACE_ITER_VERBOSE)) + print_lat_help_header(m); + } else { + if (!(trace_flags & TRACE_ITER_VERBOSE)) + print_func_help_header(m); + } +} + static int s_show(struct seq_file *m, void *v) { struct trace_iterator *iter = v; @@ -2096,17 +2113,9 @@ static int s_show(struct seq_file *m, void *v) } if (iter->trace && iter->trace->print_header) iter->trace->print_header(m); - else if (iter->iter_flags & TRACE_FILE_LAT_FMT) { - /* print nothing if the buffers are empty */ - if (trace_empty(iter)) - return 0; - print_trace_header(m, iter); - if (!(trace_flags & TRACE_ITER_VERBOSE)) - print_lat_help_header(m); - } else { - if (!(trace_flags & TRACE_ITER_VERBOSE)) - print_func_help_header(m); - } + else + trace_default_header(m); + } else if (iter->leftover) { /* * If we filled the seq_file buffer earlier, we diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 970004c5fa7..911e9864e94 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -378,6 +378,9 @@ void trace_function(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, unsigned long flags, int pc); +void trace_default_header(struct seq_file *m); +void print_trace_header(struct seq_file *m, struct trace_iterator *iter); +int trace_empty(struct trace_iterator *iter); void trace_graph_return(struct ftrace_graph_ret *trace); int trace_graph_entry(struct ftrace_graph_ent *trace); @@ -491,11 +494,29 @@ extern int trace_clock_id; /* Standard output formatting function used for function return traces */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER + +/* Flag options */ +#define TRACE_GRAPH_PRINT_OVERRUN 0x1 +#define TRACE_GRAPH_PRINT_CPU 0x2 +#define TRACE_GRAPH_PRINT_OVERHEAD 0x4 +#define TRACE_GRAPH_PRINT_PROC 0x8 +#define TRACE_GRAPH_PRINT_DURATION 0x10 +#define TRACE_GRAPH_PRINT_ABS_TIME 0x20 + extern enum print_line_t print_graph_function_flags(struct trace_iterator *iter, u32 flags); extern void print_graph_headers_flags(struct seq_file *s, u32 flags); extern enum print_line_t trace_print_graph_duration(unsigned long long duration, struct trace_seq *s); +extern void graph_trace_open(struct trace_iterator *iter); +extern void graph_trace_close(struct trace_iterator *iter); +extern int __trace_graph_entry(struct trace_array *tr, + struct ftrace_graph_ent *trace, + unsigned long flags, int pc); +extern void __trace_graph_return(struct trace_array *tr, + struct ftrace_graph_ret *trace, + unsigned long flags, int pc); + #ifdef CONFIG_DYNAMIC_FTRACE /* TODO: make this variable */ diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index de5f6518aba..dd11c830eb8 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -179,7 +179,7 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer) return ret; } -static int __trace_graph_entry(struct trace_array *tr, +int __trace_graph_entry(struct trace_array *tr, struct ftrace_graph_ent *trace, unsigned long flags, int pc) @@ -246,7 +246,7 @@ int trace_graph_thresh_entry(struct ftrace_graph_ent *trace) return trace_graph_entry(trace); } -static void __trace_graph_return(struct trace_array *tr, +void __trace_graph_return(struct trace_array *tr, struct ftrace_graph_ret *trace, unsigned long flags, int pc) @@ -1093,6 +1093,11 @@ print_graph_function_flags(struct trace_iterator *iter, u32 flags) trace_assign_type(field, entry); return print_graph_return(&field->ret, s, entry, iter, flags); } + case TRACE_STACK: + case TRACE_FN: + /* dont trace stack and functions as comments */ + return TRACE_TYPE_UNHANDLED; + default: return print_graph_comment(s, entry, iter, flags); } @@ -1170,12 +1175,12 @@ void print_graph_headers_flags(struct seq_file *s, u32 flags) seq_printf(s, " | | | |\n"); } -static void print_graph_headers(struct seq_file *s) +void print_graph_headers(struct seq_file *s) { print_graph_headers_flags(s, tracer_flags.val); } -static void graph_trace_open(struct trace_iterator *iter) +void graph_trace_open(struct trace_iterator *iter) { /* pid and depth on the last trace processed */ struct fgraph_data *data; @@ -1210,7 +1215,7 @@ static void graph_trace_open(struct trace_iterator *iter) pr_warning("function graph tracer: not enough memory\n"); } -static void graph_trace_close(struct trace_iterator *iter) +void graph_trace_close(struct trace_iterator *iter) { struct fgraph_data *data = iter->private; diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 2974bc7538c..6fd486e0cef 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -34,6 +34,9 @@ static int trace_type __read_mostly; static int save_lat_flag; +static void stop_irqsoff_tracer(struct trace_array *tr, int graph); +static int start_irqsoff_tracer(struct trace_array *tr, int graph); + #ifdef CONFIG_PREEMPT_TRACER static inline int preempt_trace(void) @@ -55,6 +58,23 @@ irq_trace(void) # define irq_trace() (0) #endif +#define TRACE_DISPLAY_GRAPH 1 + +static struct tracer_opt trace_opts[] = { +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + /* display latency trace as call graph */ + { TRACER_OPT(display-graph, TRACE_DISPLAY_GRAPH) }, +#endif + { } /* Empty entry */ +}; + +static struct tracer_flags tracer_flags = { + .val = 0, + .opts = trace_opts, +}; + +#define is_graph() (tracer_flags.val & TRACE_DISPLAY_GRAPH) + /* * Sequence count - we record it when starting a measurement and * skip the latency if the sequence has changed - some other section @@ -108,6 +128,202 @@ static struct ftrace_ops trace_ops __read_mostly = }; #endif /* CONFIG_FUNCTION_TRACER */ +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +static int irqsoff_set_flag(u32 old_flags, u32 bit, int set) +{ + int cpu; + + if (!(bit & TRACE_DISPLAY_GRAPH)) + return -EINVAL; + + if (!(is_graph() ^ set)) + return 0; + + stop_irqsoff_tracer(irqsoff_trace, !set); + + for_each_possible_cpu(cpu) + per_cpu(tracing_cpu, cpu) = 0; + + tracing_max_latency = 0; + tracing_reset_online_cpus(irqsoff_trace); + + return start_irqsoff_tracer(irqsoff_trace, set); +} + +static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) +{ + struct trace_array *tr = irqsoff_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int ret; + int cpu; + int pc; + + cpu = raw_smp_processor_id(); + if (likely(!per_cpu(tracing_cpu, cpu))) + return 0; + + local_save_flags(flags); + /* slight chance to get a false positive on tracing_cpu */ + if (!irqs_disabled_flags(flags)) + return 0; + + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) { + pc = preempt_count(); + ret = __trace_graph_entry(tr, trace, flags, pc); + } else + ret = 0; + + atomic_dec(&data->disabled); + return ret; +} + +static void irqsoff_graph_return(struct ftrace_graph_ret *trace) +{ + struct trace_array *tr = irqsoff_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + int pc; + + cpu = raw_smp_processor_id(); + if (likely(!per_cpu(tracing_cpu, cpu))) + return; + + local_save_flags(flags); + /* slight chance to get a false positive on tracing_cpu */ + if (!irqs_disabled_flags(flags)) + return; + + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) { + pc = preempt_count(); + __trace_graph_return(tr, trace, flags, pc); + } + + atomic_dec(&data->disabled); +} + +static void irqsoff_trace_open(struct trace_iterator *iter) +{ + if (is_graph()) + graph_trace_open(iter); + +} + +static void irqsoff_trace_close(struct trace_iterator *iter) +{ + if (iter->private) + graph_trace_close(iter); +} + +#define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \ + TRACE_GRAPH_PRINT_PROC) + +static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) +{ + u32 flags = GRAPH_TRACER_FLAGS; + + if (trace_flags & TRACE_ITER_LATENCY_FMT) + flags |= TRACE_GRAPH_PRINT_DURATION; + else + flags |= TRACE_GRAPH_PRINT_ABS_TIME; + + /* + * In graph mode call the graph tracer output function, + * otherwise go with the TRACE_FN event handler + */ + if (is_graph()) + return print_graph_function_flags(iter, flags); + + return TRACE_TYPE_UNHANDLED; +} + +static void irqsoff_print_header(struct seq_file *s) +{ + if (is_graph()) { + struct trace_iterator *iter = s->private; + u32 flags = GRAPH_TRACER_FLAGS; + + if (trace_flags & TRACE_ITER_LATENCY_FMT) { + /* print nothing if the buffers are empty */ + if (trace_empty(iter)) + return; + + print_trace_header(s, iter); + flags |= TRACE_GRAPH_PRINT_DURATION; + } else + flags |= TRACE_GRAPH_PRINT_ABS_TIME; + + print_graph_headers_flags(s, flags); + } else + trace_default_header(s); +} + +static void +trace_graph_function(struct trace_array *tr, + unsigned long ip, unsigned long flags, int pc) +{ + u64 time = trace_clock_local(); + struct ftrace_graph_ent ent = { + .func = ip, + .depth = 0, + }; + struct ftrace_graph_ret ret = { + .func = ip, + .depth = 0, + .calltime = time, + .rettime = time, + }; + + __trace_graph_entry(tr, &ent, flags, pc); + __trace_graph_return(tr, &ret, flags, pc); +} + +static void +__trace_function(struct trace_array *tr, + unsigned long ip, unsigned long parent_ip, + unsigned long flags, int pc) +{ + if (!is_graph()) + trace_function(tr, ip, parent_ip, flags, pc); + else { + trace_graph_function(tr, parent_ip, flags, pc); + trace_graph_function(tr, ip, flags, pc); + } +} + +#else +#define __trace_function trace_function + +static int irqsoff_set_flag(u32 old_flags, u32 bit, int set) +{ + return -EINVAL; +} + +static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) +{ + return -1; +} + +static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) +{ + return TRACE_TYPE_UNHANDLED; +} + +static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { } +static void irqsoff_print_header(struct seq_file *s) { } +static void irqsoff_trace_open(struct trace_iterator *iter) { } +static void irqsoff_trace_close(struct trace_iterator *iter) { } +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + /* * Should this new latency be reported/recorded? */ @@ -150,7 +366,7 @@ check_critical_timing(struct trace_array *tr, if (!report_latency(delta)) goto out_unlock; - trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); + __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); /* Skip 5 functions to get to the irq/preempt enable function */ __trace_stack(tr, flags, 5, pc); @@ -172,7 +388,7 @@ out_unlock: out: data->critical_sequence = max_sequence; data->preempt_timestamp = ftrace_now(cpu); - trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); + __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); } static inline void @@ -204,7 +420,7 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip) local_save_flags(flags); - trace_function(tr, ip, parent_ip, flags, preempt_count()); + __trace_function(tr, ip, parent_ip, flags, preempt_count()); per_cpu(tracing_cpu, cpu) = 1; @@ -238,7 +454,7 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip) atomic_inc(&data->disabled); local_save_flags(flags); - trace_function(tr, ip, parent_ip, flags, preempt_count()); + __trace_function(tr, ip, parent_ip, flags, preempt_count()); check_critical_timing(tr, data, parent_ip ? : ip, cpu); data->critical_start = 0; atomic_dec(&data->disabled); @@ -347,19 +563,32 @@ void trace_preempt_off(unsigned long a0, unsigned long a1) } #endif /* CONFIG_PREEMPT_TRACER */ -static void start_irqsoff_tracer(struct trace_array *tr) +static int start_irqsoff_tracer(struct trace_array *tr, int graph) { - register_ftrace_function(&trace_ops); - if (tracing_is_enabled()) + int ret = 0; + + if (!graph) + ret = register_ftrace_function(&trace_ops); + else + ret = register_ftrace_graph(&irqsoff_graph_return, + &irqsoff_graph_entry); + + if (!ret && tracing_is_enabled()) tracer_enabled = 1; else tracer_enabled = 0; + + return ret; } -static void stop_irqsoff_tracer(struct trace_array *tr) +static void stop_irqsoff_tracer(struct trace_array *tr, int graph) { tracer_enabled = 0; - unregister_ftrace_function(&trace_ops); + + if (!graph) + unregister_ftrace_function(&trace_ops); + else + unregister_ftrace_graph(); } static void __irqsoff_tracer_init(struct trace_array *tr) @@ -372,12 +601,14 @@ static void __irqsoff_tracer_init(struct trace_array *tr) /* make sure that the tracer is visible */ smp_wmb(); tracing_reset_online_cpus(tr); - start_irqsoff_tracer(tr); + + if (start_irqsoff_tracer(tr, is_graph())) + printk(KERN_ERR "failed to start irqsoff tracer\n"); } static void irqsoff_tracer_reset(struct trace_array *tr) { - stop_irqsoff_tracer(tr); + stop_irqsoff_tracer(tr, is_graph()); if (!save_lat_flag) trace_flags &= ~TRACE_ITER_LATENCY_FMT; @@ -409,9 +640,15 @@ static struct tracer irqsoff_tracer __read_mostly = .start = irqsoff_tracer_start, .stop = irqsoff_tracer_stop, .print_max = 1, + .print_header = irqsoff_print_header, + .print_line = irqsoff_print_line, + .flags = &tracer_flags, + .set_flag = irqsoff_set_flag, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_irqsoff, #endif + .open = irqsoff_trace_open, + .close = irqsoff_trace_close, }; # define register_irqsoff(trace) register_tracer(&trace) #else @@ -435,9 +672,15 @@ static struct tracer preemptoff_tracer __read_mostly = .start = irqsoff_tracer_start, .stop = irqsoff_tracer_stop, .print_max = 1, + .print_header = irqsoff_print_header, + .print_line = irqsoff_print_line, + .flags = &tracer_flags, + .set_flag = irqsoff_set_flag, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_preemptoff, #endif + .open = irqsoff_trace_open, + .close = irqsoff_trace_close, }; # define register_preemptoff(trace) register_tracer(&trace) #else @@ -463,9 +706,15 @@ static struct tracer preemptirqsoff_tracer __read_mostly = .start = irqsoff_tracer_start, .stop = irqsoff_tracer_stop, .print_max = 1, + .print_header = irqsoff_print_header, + .print_line = irqsoff_print_line, + .flags = &tracer_flags, + .set_flag = irqsoff_set_flag, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_preemptirqsoff, #endif + .open = irqsoff_trace_open, + .close = irqsoff_trace_close, }; # define register_preemptirqsoff(trace) register_tracer(&trace) -- cgit v1.2.3-70-g09d2 From 72c9ddfd4c5bf54ef03cfdf57026416cb678eeba Mon Sep 17 00:00:00 2001 From: David Miller Date: Tue, 20 Apr 2010 15:47:11 -0700 Subject: ring-buffer: Make non-consuming read less expensive with lots of cpus. When performing a non-consuming read, a synchronize_sched() is performed once for every cpu which is actively tracing. This is very expensive, and can make it take several seconds to open up the 'trace' file with lots of cpus. Only one synchronize_sched() call is actually necessary. What is desired is for all cpus to see the disabling state change. So we transform the existing sequence: for_each_cpu() { ring_buffer_read_start(); } where each ring_buffer_start() call performs a synchronize_sched(), into the following: for_each_cpu() { ring_buffer_read_prepare(); } ring_buffer_read_prepare_sync(); for_each_cpu() { ring_buffer_read_start(); } wherein only the single ring_buffer_read_prepare_sync() call needs to do the synchronize_sched(). The first phase, via ring_buffer_read_prepare(), allocates the 'iter' memory and increments ->record_disabled. In the second phase, ring_buffer_read_prepare_sync() makes sure this ->record_disabled state is visible fully to all cpus. And in the final third phase, the ring_buffer_read_start() calls reset the 'iter' objects allocated in the first phase since we now know that none of the cpus are adding trace entries any more. This makes openning the 'trace' file nearly instantaneous on a sparc64 Niagara2 box with 128 cpus tracing. Signed-off-by: David S. Miller LKML-Reference: <20100420.154711.11246950.davem@davemloft.net> Signed-off-by: Steven Rostedt --- include/linux/ring_buffer.h | 4 ++- kernel/trace/ring_buffer.c | 64 ++++++++++++++++++++++++++++++++++++++------- kernel/trace/trace.c | 11 +++++--- 3 files changed, 65 insertions(+), 14 deletions(-) (limited to 'include') diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index c8297761e41..25b4f686d91 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -127,7 +127,9 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts, unsigned long *lost_events); struct ring_buffer_iter * -ring_buffer_read_start(struct ring_buffer *buffer, int cpu); +ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu); +void ring_buffer_read_prepare_sync(void); +void ring_buffer_read_start(struct ring_buffer_iter *iter); void ring_buffer_read_finish(struct ring_buffer_iter *iter); struct ring_buffer_event * diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 5885cdfc41f..2a090448ef6 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3332,23 +3332,30 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts, EXPORT_SYMBOL_GPL(ring_buffer_consume); /** - * ring_buffer_read_start - start a non consuming read of the buffer + * ring_buffer_read_prepare - Prepare for a non consuming read of the buffer * @buffer: The ring buffer to read from * @cpu: The cpu buffer to iterate over * - * This starts up an iteration through the buffer. It also disables - * the recording to the buffer until the reading is finished. - * This prevents the reading from being corrupted. This is not - * a consuming read, so a producer is not expected. + * This performs the initial preparations necessary to iterate + * through the buffer. Memory is allocated, buffer recording + * is disabled, and the iterator pointer is returned to the caller. * - * Must be paired with ring_buffer_finish. + * Disabling buffer recordng prevents the reading from being + * corrupted. This is not a consuming read, so a producer is not + * expected. + * + * After a sequence of ring_buffer_read_prepare calls, the user is + * expected to make at least one call to ring_buffer_prepare_sync. + * Afterwards, ring_buffer_read_start is invoked to get things going + * for real. + * + * This overall must be paired with ring_buffer_finish. */ struct ring_buffer_iter * -ring_buffer_read_start(struct ring_buffer *buffer, int cpu) +ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu) { struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_iter *iter; - unsigned long flags; if (!cpumask_test_cpu(cpu, buffer->cpumask)) return NULL; @@ -3362,15 +3369,52 @@ ring_buffer_read_start(struct ring_buffer *buffer, int cpu) iter->cpu_buffer = cpu_buffer; atomic_inc(&cpu_buffer->record_disabled); + + return iter; +} +EXPORT_SYMBOL_GPL(ring_buffer_read_prepare); + +/** + * ring_buffer_read_prepare_sync - Synchronize a set of prepare calls + * + * All previously invoked ring_buffer_read_prepare calls to prepare + * iterators will be synchronized. Afterwards, read_buffer_read_start + * calls on those iterators are allowed. + */ +void +ring_buffer_read_prepare_sync(void) +{ synchronize_sched(); +} +EXPORT_SYMBOL_GPL(ring_buffer_read_prepare_sync); + +/** + * ring_buffer_read_start - start a non consuming read of the buffer + * @iter: The iterator returned by ring_buffer_read_prepare + * + * This finalizes the startup of an iteration through the buffer. + * The iterator comes from a call to ring_buffer_read_prepare and + * an intervening ring_buffer_read_prepare_sync must have been + * performed. + * + * Must be paired with ring_buffer_finish. + */ +void +ring_buffer_read_start(struct ring_buffer_iter *iter) +{ + struct ring_buffer_per_cpu *cpu_buffer; + unsigned long flags; + + if (!iter) + return; + + cpu_buffer = iter->cpu_buffer; spin_lock_irqsave(&cpu_buffer->reader_lock, flags); arch_spin_lock(&cpu_buffer->lock); rb_iter_reset(iter); arch_spin_unlock(&cpu_buffer->lock); spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags); - - return iter; } EXPORT_SYMBOL_GPL(ring_buffer_read_start); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8b9ba41ec14..756d7283318 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2201,15 +2201,20 @@ __tracing_open(struct inode *inode, struct file *file) if (iter->cpu_file == TRACE_PIPE_ALL_CPU) { for_each_tracing_cpu(cpu) { - iter->buffer_iter[cpu] = - ring_buffer_read_start(iter->tr->buffer, cpu); + ring_buffer_read_prepare(iter->tr->buffer, cpu); + } + ring_buffer_read_prepare_sync(); + for_each_tracing_cpu(cpu) { + ring_buffer_read_start(iter->buffer_iter[cpu]); tracing_iter_reset(iter, cpu); } } else { cpu = iter->cpu_file; iter->buffer_iter[cpu] = - ring_buffer_read_start(iter->tr->buffer, cpu); + ring_buffer_read_prepare(iter->tr->buffer, cpu); + ring_buffer_read_prepare_sync(); + ring_buffer_read_start(iter->buffer_iter[cpu]); tracing_iter_reset(iter, cpu); } -- cgit v1.2.3-70-g09d2 From 73266fc1df2f94cf72b3beba3eee3b88ed0b0664 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 22 Apr 2010 05:05:45 +0200 Subject: hw-breakpoints: Tag ptrace breakpoint as exclude_kernel Tag ptrace breakpoints with the exclude_kernel attribute set. This will make it easier to set generic policies on breakpoints, when it comes to ensure nobody unpriviliged try to breakpoint on the kernel. Signed-off-by: Frederic Weisbecker Acked-by: Paul Mundt Cc: Will Deacon Cc: Mahesh Salgaonkar Cc: K. Prasad Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Ingo Molnar --- arch/sh/kernel/ptrace_32.c | 2 +- arch/x86/kernel/ptrace.c | 2 +- include/linux/hw_breakpoint.h | 6 ++++++ 3 files changed, 8 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c index 7759a9a9321..d4104ce9fe5 100644 --- a/arch/sh/kernel/ptrace_32.c +++ b/arch/sh/kernel/ptrace_32.c @@ -85,7 +85,7 @@ static int set_single_step(struct task_struct *tsk, unsigned long addr) bp = thread->ptrace_bps[0]; if (!bp) { - hw_breakpoint_init(&attr); + ptrace_breakpoint_init(&attr); attr.bp_addr = addr; attr.bp_len = HW_BREAKPOINT_LEN_2; diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 055be0afd33..70c4872cd8a 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -688,7 +688,7 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr, struct perf_event_attr attr; if (!t->ptrace_bps[nr]) { - hw_breakpoint_init(&attr); + ptrace_breakpoint_init(&attr); /* * Put stub len and type to register (reserve) an inactive but * correct bp diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h index c70d27af03f..a0aa5a9cfb0 100644 --- a/include/linux/hw_breakpoint.h +++ b/include/linux/hw_breakpoint.h @@ -34,6 +34,12 @@ static inline void hw_breakpoint_init(struct perf_event_attr *attr) attr->sample_period = 1; } +static inline void ptrace_breakpoint_init(struct perf_event_attr *attr) +{ + hw_breakpoint_init(attr); + attr->exclude_kernel = 1; +} + static inline unsigned long hw_breakpoint_addr(struct perf_event *bp) { return bp->attr.bp_addr; -- cgit v1.2.3-70-g09d2 From 0102752e4c9e0655b39734550d4c35327954f7f9 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sun, 11 Apr 2010 18:55:56 +0200 Subject: hw-breakpoints: Separate constraint space for data and instruction breakpoints There are two outstanding fashions for archs to implement hardware breakpoints. The first is to separate breakpoint address pattern definition space between data and instruction breakpoints. We then have typically distinct instruction address breakpoint registers and data address breakpoint registers, delivered with separate control registers for data and instruction breakpoints as well. This is the case of PowerPc and ARM for example. The second consists in having merged breakpoint address space definition between data and instruction breakpoint. Address registers can host either instruction or data address and the access mode for the breakpoint is defined in a control register. This is the case of x86 and Super H. This patch adds a new CONFIG_HAVE_MIXED_BREAKPOINTS_REGS config that archs can select if they belong to the second case. Those will have their slot allocation merged for instructions and data breakpoints. The others will have a separate slot tracking between data and instruction breakpoints. Signed-off-by: Frederic Weisbecker Acked-by: Paul Mundt Cc: Will Deacon Cc: Mahesh Salgaonkar Cc: K. Prasad Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Ingo Molnar --- arch/Kconfig | 11 ++++++ arch/sh/Kconfig | 1 + arch/x86/Kconfig | 1 + include/linux/hw_breakpoint.h | 9 +++-- kernel/hw_breakpoint.c | 86 +++++++++++++++++++++++++++++-------------- 5 files changed, 78 insertions(+), 30 deletions(-) (limited to 'include') diff --git a/arch/Kconfig b/arch/Kconfig index f06010fb483..acda512da2e 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -137,6 +137,17 @@ config HAVE_HW_BREAKPOINT bool depends on PERF_EVENTS +config HAVE_MIXED_BREAKPOINTS_REGS + bool + depends on HAVE_HW_BREAKPOINT + help + Depending on the arch implementation of hardware breakpoints, + some of them have separate registers for data and instruction + breakpoints addresses, others have mixed registers to store + them but define the access type in a control register. + Select this option if your arch implements breakpoints under the + latter fashion. + config HAVE_USER_RETURN_NOTIFIER bool diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index 8d90564c2bc..e6d8ab5cfa9 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -44,6 +44,7 @@ config SUPERH32 select HAVE_FUNCTION_GRAPH_TRACER select HAVE_ARCH_KGDB select HAVE_HW_BREAKPOINT + select HAVE_MIXED_BREAKPOINTS_REGS select PERF_EVENTS if HAVE_HW_BREAKPOINT select ARCH_HIBERNATION_POSSIBLE if MMU diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 97a95dfd118..01177dcbe26 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -53,6 +53,7 @@ config X86 select HAVE_KERNEL_LZMA select HAVE_KERNEL_LZO select HAVE_HW_BREAKPOINT + select HAVE_MIXED_BREAKPOINTS_REGS select PERF_EVENTS select ANON_INODES select HAVE_ARCH_KMEMCHECK diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h index a0aa5a9cfb0..7e889909309 100644 --- a/include/linux/hw_breakpoint.h +++ b/include/linux/hw_breakpoint.h @@ -9,9 +9,12 @@ enum { }; enum { - HW_BREAKPOINT_R = 1, - HW_BREAKPOINT_W = 2, - HW_BREAKPOINT_X = 4, + HW_BREAKPOINT_EMPTY = 0, + HW_BREAKPOINT_R = 1, + HW_BREAKPOINT_W = 2, + HW_BREAKPOINT_RW = HW_BREAKPOINT_R | HW_BREAKPOINT_W, + HW_BREAKPOINT_X = 4, + HW_BREAKPOINT_INVALID = HW_BREAKPOINT_RW | HW_BREAKPOINT_X, }; #ifdef __KERNEL__ diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index 89e8a050c43..8ead1345e33 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -45,18 +45,28 @@ #include +enum bp_type_idx { + TYPE_INST = 0, +#ifdef CONFIG_HAVE_MIXED_BREAKPOINTS_REGS + TYPE_DATA = 0, +#else + TYPE_DATA = 1, +#endif + TYPE_MAX +}; + /* * Constraints data */ /* Number of pinned cpu breakpoints in a cpu */ -static DEFINE_PER_CPU(unsigned int, nr_cpu_bp_pinned); +static DEFINE_PER_CPU(unsigned int, nr_cpu_bp_pinned[TYPE_MAX]); /* Number of pinned task breakpoints in a cpu */ -static DEFINE_PER_CPU(unsigned int, nr_task_bp_pinned[HBP_NUM]); +static DEFINE_PER_CPU(unsigned int, nr_task_bp_pinned[TYPE_MAX][HBP_NUM]); /* Number of non-pinned cpu/task breakpoints in a cpu */ -static DEFINE_PER_CPU(unsigned int, nr_bp_flexible); +static DEFINE_PER_CPU(unsigned int, nr_bp_flexible[TYPE_MAX]); /* Gather the number of total pinned and un-pinned bp in a cpuset */ struct bp_busy_slots { @@ -67,14 +77,22 @@ struct bp_busy_slots { /* Serialize accesses to the above constraints */ static DEFINE_MUTEX(nr_bp_mutex); +static inline enum bp_type_idx find_slot_idx(struct perf_event *bp) +{ + if (bp->attr.bp_type & HW_BREAKPOINT_RW) + return TYPE_DATA; + + return TYPE_INST; +} + /* * Report the maximum number of pinned breakpoints a task * have in this cpu */ -static unsigned int max_task_bp_pinned(int cpu) +static unsigned int max_task_bp_pinned(int cpu, enum bp_type_idx type) { int i; - unsigned int *tsk_pinned = per_cpu(nr_task_bp_pinned, cpu); + unsigned int *tsk_pinned = per_cpu(nr_task_bp_pinned[type], cpu); for (i = HBP_NUM -1; i >= 0; i--) { if (tsk_pinned[i] > 0) @@ -84,7 +102,7 @@ static unsigned int max_task_bp_pinned(int cpu) return 0; } -static int task_bp_pinned(struct task_struct *tsk) +static int task_bp_pinned(struct task_struct *tsk, enum bp_type_idx type) { struct perf_event_context *ctx = tsk->perf_event_ctxp; struct list_head *list; @@ -105,7 +123,8 @@ static int task_bp_pinned(struct task_struct *tsk) */ list_for_each_entry(bp, list, event_entry) { if (bp->attr.type == PERF_TYPE_BREAKPOINT) - count++; + if (find_slot_idx(bp) == type) + count++; } raw_spin_unlock_irqrestore(&ctx->lock, flags); @@ -118,18 +137,19 @@ static int task_bp_pinned(struct task_struct *tsk) * a given cpu (cpu > -1) or in all of them (cpu = -1). */ static void -fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp) +fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp, + enum bp_type_idx type) { int cpu = bp->cpu; struct task_struct *tsk = bp->ctx->task; if (cpu >= 0) { - slots->pinned = per_cpu(nr_cpu_bp_pinned, cpu); + slots->pinned = per_cpu(nr_cpu_bp_pinned[type], cpu); if (!tsk) - slots->pinned += max_task_bp_pinned(cpu); + slots->pinned += max_task_bp_pinned(cpu, type); else - slots->pinned += task_bp_pinned(tsk); - slots->flexible = per_cpu(nr_bp_flexible, cpu); + slots->pinned += task_bp_pinned(tsk, type); + slots->flexible = per_cpu(nr_bp_flexible[type], cpu); return; } @@ -137,16 +157,16 @@ fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp) for_each_online_cpu(cpu) { unsigned int nr; - nr = per_cpu(nr_cpu_bp_pinned, cpu); + nr = per_cpu(nr_cpu_bp_pinned[type], cpu); if (!tsk) - nr += max_task_bp_pinned(cpu); + nr += max_task_bp_pinned(cpu, type); else - nr += task_bp_pinned(tsk); + nr += task_bp_pinned(tsk, type); if (nr > slots->pinned) slots->pinned = nr; - nr = per_cpu(nr_bp_flexible, cpu); + nr = per_cpu(nr_bp_flexible[type], cpu); if (nr > slots->flexible) slots->flexible = nr; @@ -156,14 +176,15 @@ fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp) /* * Add a pinned breakpoint for the given task in our constraint table */ -static void toggle_bp_task_slot(struct task_struct *tsk, int cpu, bool enable) +static void toggle_bp_task_slot(struct task_struct *tsk, int cpu, bool enable, + enum bp_type_idx type) { unsigned int *tsk_pinned; int count = 0; - count = task_bp_pinned(tsk); + count = task_bp_pinned(tsk, type); - tsk_pinned = per_cpu(nr_task_bp_pinned, cpu); + tsk_pinned = per_cpu(nr_task_bp_pinned[type], cpu); if (enable) { tsk_pinned[count]++; if (count > 0) @@ -178,7 +199,8 @@ static void toggle_bp_task_slot(struct task_struct *tsk, int cpu, bool enable) /* * Add/remove the given breakpoint in our constraint table */ -static void toggle_bp_slot(struct perf_event *bp, bool enable) +static void +toggle_bp_slot(struct perf_event *bp, bool enable, enum bp_type_idx type) { int cpu = bp->cpu; struct task_struct *tsk = bp->ctx->task; @@ -186,20 +208,20 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable) /* Pinned counter task profiling */ if (tsk) { if (cpu >= 0) { - toggle_bp_task_slot(tsk, cpu, enable); + toggle_bp_task_slot(tsk, cpu, enable, type); return; } for_each_online_cpu(cpu) - toggle_bp_task_slot(tsk, cpu, enable); + toggle_bp_task_slot(tsk, cpu, enable, type); return; } /* Pinned counter cpu profiling */ if (enable) - per_cpu(nr_cpu_bp_pinned, bp->cpu)++; + per_cpu(nr_cpu_bp_pinned[type], bp->cpu)++; else - per_cpu(nr_cpu_bp_pinned, bp->cpu)--; + per_cpu(nr_cpu_bp_pinned[type], bp->cpu)--; } /* @@ -246,14 +268,21 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable) static int __reserve_bp_slot(struct perf_event *bp) { struct bp_busy_slots slots = {0}; + enum bp_type_idx type; - fetch_bp_busy_slots(&slots, bp); + /* Basic checks */ + if (bp->attr.bp_type == HW_BREAKPOINT_EMPTY || + bp->attr.bp_type == HW_BREAKPOINT_INVALID) + return -EINVAL; + + type = find_slot_idx(bp); + fetch_bp_busy_slots(&slots, bp, type); /* Flexible counters need to keep at least one slot */ if (slots.pinned + (!!slots.flexible) == HBP_NUM) return -ENOSPC; - toggle_bp_slot(bp, true); + toggle_bp_slot(bp, true, type); return 0; } @@ -273,7 +302,10 @@ int reserve_bp_slot(struct perf_event *bp) static void __release_bp_slot(struct perf_event *bp) { - toggle_bp_slot(bp, false); + enum bp_type_idx type; + + type = find_slot_idx(bp); + toggle_bp_slot(bp, false, type); } void release_bp_slot(struct perf_event *bp) -- cgit v1.2.3-70-g09d2 From feef47d0cb530e8419dfa0b48141b538b89b1b1a Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 23 Apr 2010 05:59:55 +0200 Subject: hw-breakpoints: Get the number of available registers on boot dynamically The breakpoint generic layer assumes that archs always know in advance the static number of address registers available to host breakpoints through the HBP_NUM macro. However this is not true for every archs. For example Arm needs to get this information dynamically to handle the compatiblity between different versions. To solve this, this patch proposes to drop the static HBP_NUM macro and let the arch provide the number of available slots through a new hw_breakpoint_slots() function. For archs that have CONFIG_HAVE_MIXED_BREAKPOINTS_REGS selected, it will be called once as the number of registers fits for instruction and data breakpoints together. For the others it will be called first to get the number of instruction breakpoint registers and another time to get the data breakpoint registers, the targeted type is given as a parameter of hw_breakpoint_slots(). Reported-by: Will Deacon Signed-off-by: Frederic Weisbecker Acked-by: Paul Mundt Cc: Mahesh Salgaonkar Cc: K. Prasad Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Jason Wessel Cc: Ingo Molnar --- arch/sh/include/asm/hw_breakpoint.h | 5 ++++ arch/x86/include/asm/hw_breakpoint.h | 5 ++++ include/linux/hw_breakpoint.h | 10 +++++++ kernel/hw_breakpoint.c | 53 ++++++++++++++++++++++++++++-------- kernel/trace/trace_ksym.c | 26 +++++------------- 5 files changed, 68 insertions(+), 31 deletions(-) (limited to 'include') diff --git a/arch/sh/include/asm/hw_breakpoint.h b/arch/sh/include/asm/hw_breakpoint.h index 382bad937dc..e14cad96798 100644 --- a/arch/sh/include/asm/hw_breakpoint.h +++ b/arch/sh/include/asm/hw_breakpoint.h @@ -46,6 +46,11 @@ struct pmu; /* Maximum number of UBC channels */ #define HBP_NUM 2 +static inline int hw_breakpoint_slots(int type) +{ + return HBP_NUM; +} + /* arch/sh/kernel/hw_breakpoint.c */ extern int arch_check_bp_in_kernelspace(struct perf_event *bp); extern int arch_validate_hwbkpt_settings(struct perf_event *bp); diff --git a/arch/x86/include/asm/hw_breakpoint.h b/arch/x86/include/asm/hw_breakpoint.h index c77a5a6fab9..942255310e6 100644 --- a/arch/x86/include/asm/hw_breakpoint.h +++ b/arch/x86/include/asm/hw_breakpoint.h @@ -41,6 +41,11 @@ struct arch_hw_breakpoint { /* Total number of available HW breakpoint registers */ #define HBP_NUM 4 +static inline int hw_breakpoint_slots(int type) +{ + return HBP_NUM; +} + struct perf_event; struct pmu; diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h index 7e889909309..a2d6ea49ec5 100644 --- a/include/linux/hw_breakpoint.h +++ b/include/linux/hw_breakpoint.h @@ -17,6 +17,16 @@ enum { HW_BREAKPOINT_INVALID = HW_BREAKPOINT_RW | HW_BREAKPOINT_X, }; +enum bp_type_idx { + TYPE_INST = 0, +#ifdef CONFIG_HAVE_MIXED_BREAKPOINTS_REGS + TYPE_DATA = 0, +#else + TYPE_DATA = 1, +#endif + TYPE_MAX +}; + #ifdef __KERNEL__ #include diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index 974498b858f..684b710cbb9 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -40,20 +40,12 @@ #include #include #include +#include #include #include #include -enum bp_type_idx { - TYPE_INST = 0, -#ifdef CONFIG_HAVE_MIXED_BREAKPOINTS_REGS - TYPE_DATA = 0, -#else - TYPE_DATA = 1, -#endif - TYPE_MAX -}; /* * Constraints data @@ -63,11 +55,15 @@ enum bp_type_idx { static DEFINE_PER_CPU(unsigned int, nr_cpu_bp_pinned[TYPE_MAX]); /* Number of pinned task breakpoints in a cpu */ -static DEFINE_PER_CPU(unsigned int, nr_task_bp_pinned[TYPE_MAX][HBP_NUM]); +static DEFINE_PER_CPU(unsigned int, *nr_task_bp_pinned[TYPE_MAX]); /* Number of non-pinned cpu/task breakpoints in a cpu */ static DEFINE_PER_CPU(unsigned int, nr_bp_flexible[TYPE_MAX]); +static int nr_slots[TYPE_MAX]; + +static int constraints_initialized; + /* Gather the number of total pinned and un-pinned bp in a cpuset */ struct bp_busy_slots { unsigned int pinned; @@ -99,7 +95,7 @@ static unsigned int max_task_bp_pinned(int cpu, enum bp_type_idx type) int i; unsigned int *tsk_pinned = per_cpu(nr_task_bp_pinned[type], cpu); - for (i = HBP_NUM -1; i >= 0; i--) { + for (i = nr_slots[type] - 1; i >= 0; i--) { if (tsk_pinned[i] > 0) return i + 1; } @@ -292,6 +288,10 @@ static int __reserve_bp_slot(struct perf_event *bp) enum bp_type_idx type; int weight; + /* We couldn't initialize breakpoint constraints on boot */ + if (!constraints_initialized) + return -ENOMEM; + /* Basic checks */ if (bp->attr.bp_type == HW_BREAKPOINT_EMPTY || bp->attr.bp_type == HW_BREAKPOINT_INVALID) @@ -304,7 +304,7 @@ static int __reserve_bp_slot(struct perf_event *bp) fetch_this_slot(&slots, weight); /* Flexible counters need to keep at least one slot */ - if (slots.pinned + (!!slots.flexible) > HBP_NUM) + if (slots.pinned + (!!slots.flexible) > nr_slots[type]) return -ENOSPC; toggle_bp_slot(bp, true, type, weight); @@ -551,7 +551,36 @@ static struct notifier_block hw_breakpoint_exceptions_nb = { static int __init init_hw_breakpoint(void) { + unsigned int **task_bp_pinned; + int cpu, err_cpu; + int i; + + for (i = 0; i < TYPE_MAX; i++) + nr_slots[i] = hw_breakpoint_slots(i); + + for_each_possible_cpu(cpu) { + for (i = 0; i < TYPE_MAX; i++) { + task_bp_pinned = &per_cpu(nr_task_bp_pinned[i], cpu); + *task_bp_pinned = kzalloc(sizeof(int) * nr_slots[i], + GFP_KERNEL); + if (!*task_bp_pinned) + goto err_alloc; + } + } + + constraints_initialized = 1; + return register_die_notifier(&hw_breakpoint_exceptions_nb); + + err_alloc: + for_each_possible_cpu(err_cpu) { + if (err_cpu == cpu) + break; + for (i = 0; i < TYPE_MAX; i++) + kfree(per_cpu(nr_task_bp_pinned[i], cpu)); + } + + return -ENOMEM; } core_initcall(init_hw_breakpoint); diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c index d59cd687947..8eaf00749b6 100644 --- a/kernel/trace/trace_ksym.c +++ b/kernel/trace/trace_ksym.c @@ -34,12 +34,6 @@ #include -/* - * For now, let us restrict the no. of symbols traced simultaneously to number - * of available hardware breakpoint registers. - */ -#define KSYM_TRACER_MAX HBP_NUM - #define KSYM_TRACER_OP_LEN 3 /* rw- */ struct trace_ksym { @@ -53,7 +47,6 @@ struct trace_ksym { static struct trace_array *ksym_trace_array; -static unsigned int ksym_filter_entry_count; static unsigned int ksym_tracing_enabled; static HLIST_HEAD(ksym_filter_head); @@ -181,13 +174,6 @@ int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) struct trace_ksym *entry; int ret = -ENOMEM; - if (ksym_filter_entry_count >= KSYM_TRACER_MAX) { - printk(KERN_ERR "ksym_tracer: Maximum limit:(%d) reached. No" - " new requests for tracing can be accepted now.\n", - KSYM_TRACER_MAX); - return -ENOSPC; - } - entry = kzalloc(sizeof(struct trace_ksym), GFP_KERNEL); if (!entry) return -ENOMEM; @@ -203,13 +189,17 @@ int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) if (IS_ERR(entry->ksym_hbp)) { ret = PTR_ERR(entry->ksym_hbp); - printk(KERN_INFO "ksym_tracer request failed. Try again" - " later!!\n"); + if (ret == -ENOSPC) { + printk(KERN_ERR "ksym_tracer: Maximum limit reached." + " No new requests for tracing can be accepted now.\n"); + } else { + printk(KERN_INFO "ksym_tracer request failed. Try again" + " later!!\n"); + } goto err; } hlist_add_head_rcu(&(entry->ksym_hlist), &ksym_filter_head); - ksym_filter_entry_count++; return 0; @@ -265,7 +255,6 @@ static void __ksym_trace_reset(void) hlist_for_each_entry_safe(entry, node, node1, &ksym_filter_head, ksym_hlist) { unregister_wide_hw_breakpoint(entry->ksym_hbp); - ksym_filter_entry_count--; hlist_del_rcu(&(entry->ksym_hlist)); synchronize_rcu(); kfree(entry); @@ -338,7 +327,6 @@ static ssize_t ksym_trace_filter_write(struct file *file, goto out_unlock; } /* Error or "symbol:---" case: drop it */ - ksym_filter_entry_count--; hlist_del_rcu(&(entry->ksym_hlist)); synchronize_rcu(); kfree(entry); -- cgit v1.2.3-70-g09d2 From 4dbf6bc239c169b032777616806ecc648058f6b2 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 4 May 2010 11:24:01 -0400 Subject: tracing: Convert nop macros to static inlines The ftrace.h file contains several functions as macros when the functions are disabled due to config options. This patch converts most of them to static inlines. There are two exceptions: register_ftrace_function() and unregister_ftrace_function() This is because their parameter "ops" must not be evaluated since code using the function is allowed to #ifdef out the creation of the parameter. This also fixes an error caused by recent changes: kernel/trace/trace_irqsoff.c: In function 'start_irqsoff_tracer': kernel/trace/trace_irqsoff.c:571: error: expected expression before 'do' Reported-by: Ingo Molnar Signed-off-by: Steven Rostedt --- include/linux/ftrace.h | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) (limited to 'include') diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 8415a522f43..e0ae83bbd9c 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -82,9 +82,13 @@ void clear_ftrace_function(void); extern void ftrace_stub(unsigned long a0, unsigned long a1); #else /* !CONFIG_FUNCTION_TRACER */ -# define register_ftrace_function(ops) do { } while (0) -# define unregister_ftrace_function(ops) do { } while (0) -# define clear_ftrace_function(ops) do { } while (0) +/* + * (un)register_ftrace_function must be a macro since the ops parameter + * must not be evaluated. + */ +#define register_ftrace_function(ops) ({ 0; }) +#define unregister_ftrace_function(ops) ({ 0; }) +static inline void clear_ftrace_function(void) { } static inline void ftrace_kill(void) { } static inline void ftrace_stop(void) { } static inline void ftrace_start(void) { } @@ -237,11 +241,13 @@ extern int skip_trace(unsigned long ip); extern void ftrace_disable_daemon(void); extern void ftrace_enable_daemon(void); #else -# define skip_trace(ip) ({ 0; }) -# define ftrace_force_update() ({ 0; }) -# define ftrace_set_filter(buf, len, reset) do { } while (0) -# define ftrace_disable_daemon() do { } while (0) -# define ftrace_enable_daemon() do { } while (0) +static inline int skip_trace(unsigned long ip) { return 0; } +static inline int ftrace_force_update(void) { return 0; } +static inline void ftrace_set_filter(unsigned char *buf, int len, int reset) +{ +} +static inline void ftrace_disable_daemon(void) { } +static inline void ftrace_enable_daemon(void) { } static inline void ftrace_release_mod(struct module *mod) {} static inline int register_ftrace_command(struct ftrace_func_command *cmd) { @@ -314,16 +320,16 @@ static inline void __ftrace_enabled_restore(int enabled) extern void time_hardirqs_on(unsigned long a0, unsigned long a1); extern void time_hardirqs_off(unsigned long a0, unsigned long a1); #else -# define time_hardirqs_on(a0, a1) do { } while (0) -# define time_hardirqs_off(a0, a1) do { } while (0) + static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } + static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } #endif #ifdef CONFIG_PREEMPT_TRACER extern void trace_preempt_on(unsigned long a0, unsigned long a1); extern void trace_preempt_off(unsigned long a0, unsigned long a1); #else -# define trace_preempt_on(a0, a1) do { } while (0) -# define trace_preempt_off(a0, a1) do { } while (0) + static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { } + static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { } #endif #ifdef CONFIG_FTRACE_MCOUNT_RECORD -- cgit v1.2.3-70-g09d2 From 4677d4a53e0d565742277e8913e91c821453e63e Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Mon, 3 May 2010 14:57:11 +0200 Subject: arch, hweight: Fix compilation errors Fix function prototype visibility issues when compiling for non-x86 architectures. Tested with crosstool (ftp://ftp.kernel.org/pub/tools/crosstool/) with alpha, ia64 and sparc targets. Signed-off-by: Borislav Petkov LKML-Reference: <20100503130736.GD26107@aftab> Signed-off-by: H. Peter Anvin --- include/asm-generic/bitops/arch_hweight.h | 8 ++++---- include/linux/bitops.h | 5 +++++ 2 files changed, 9 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/asm-generic/bitops/arch_hweight.h b/include/asm-generic/bitops/arch_hweight.h index 9a81c1e9436..6a211f40665 100644 --- a/include/asm-generic/bitops/arch_hweight.h +++ b/include/asm-generic/bitops/arch_hweight.h @@ -3,22 +3,22 @@ #include -inline unsigned int __arch_hweight32(unsigned int w) +static inline unsigned int __arch_hweight32(unsigned int w) { return __sw_hweight32(w); } -inline unsigned int __arch_hweight16(unsigned int w) +static inline unsigned int __arch_hweight16(unsigned int w) { return __sw_hweight16(w); } -inline unsigned int __arch_hweight8(unsigned int w) +static inline unsigned int __arch_hweight8(unsigned int w) { return __sw_hweight8(w); } -inline unsigned long __arch_hweight64(__u64 w) +static inline unsigned long __arch_hweight64(__u64 w) { return __sw_hweight64(w); } diff --git a/include/linux/bitops.h b/include/linux/bitops.h index c55d5bc4ee5..26caa608ccd 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -10,6 +10,11 @@ #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) #endif +extern unsigned int __sw_hweight8(unsigned int w); +extern unsigned int __sw_hweight16(unsigned int w); +extern unsigned int __sw_hweight32(unsigned int w); +extern unsigned long __sw_hweight64(__u64 w); + /* * Include this here because some architectures need generic_ffs/fls in * scope -- cgit v1.2.3-70-g09d2 From 2c2df8418ac7908eec4558407b83f16739006c54 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 30 Mar 2010 01:07:02 -0700 Subject: x86, acpi/irq: Introduce apci_isa_irq_to_gsi There are a number of cases where the current code makes the assumption that isa irqs identity map to the first 16 acpi global system intereupts. In most instances that assumption is correct as that is the required behaviour in dual i8259 mode and the default behavior in ioapic mode. However there are some systems out there that take advantage of acpis interrupt remapping for the isa irqs to have a completely different mapping of isa_irq to gsi. Introduce acpi_isa_irq_to_gsi to perform this mapping explicitly in the code that needs it. Initially this will be just the current assumed identity mapping to ensure it's introduction does not cause regressions. Signed-off-by: Eric W. Biederman LKML-Reference: <1269936436-7039-1-git-send-email-ebiederm@xmission.com> Signed-off-by: H. Peter Anvin --- arch/ia64/kernel/acpi.c | 8 ++++++++ arch/x86/kernel/acpi/boot.c | 8 ++++++++ include/linux/acpi.h | 1 + 3 files changed, 17 insertions(+) (limited to 'include') diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c index 4d1a7e9314c..c6c90f39f4d 100644 --- a/arch/ia64/kernel/acpi.c +++ b/arch/ia64/kernel/acpi.c @@ -785,6 +785,14 @@ int acpi_gsi_to_irq(u32 gsi, unsigned int *irq) return 0; } +int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi) +{ + if (isa_irq >= 16) + return -1; + *gsi = isa_irq; + return 0; +} + /* * ACPI based hotplug CPU support */ diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index cd40aba6aa9..da718d67259 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -458,6 +458,14 @@ int acpi_gsi_to_irq(u32 gsi, unsigned int *irq) return 0; } +int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi) +{ + if (isa_irq >= 16) + return -1; + *gsi = isa_irq; + return 0; +} + /* * success: return IRQ number (>=0) * failure: return < 0 diff --git a/include/linux/acpi.h b/include/linux/acpi.h index b926afe8c03..7a937dabcc4 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -116,6 +116,7 @@ extern unsigned long acpi_realmode_flags; int acpi_register_gsi (struct device *dev, u32 gsi, int triggering, int polarity); int acpi_gsi_to_irq (u32 gsi, unsigned int *irq); +int acpi_isa_irq_to_gsi (unsigned isa_irq, u32 *gsi); #ifdef CONFIG_X86_IO_APIC extern int acpi_get_override_irq(int bus_irq, int *trigger, int *polarity); -- cgit v1.2.3-70-g09d2 From 9a0a91bb56d2915cdb8585717de38376ad20fef9 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 30 Mar 2010 01:07:03 -0700 Subject: x86, acpi/irq: Teach acpi_get_override_irq to take a gsi not an isa_irq In perverse acpi implementations the isa irqs are not identity mapped to the first 16 gsi. Furthermore at least the extended interrupt resource capability may return gsi's and not isa irqs. So since what we get from acpi is a gsi teach acpi_get_overrride_irq to operate on a gsi instead of an isa_irq. Signed-off-by: Eric W. Biederman LKML-Reference: <1269936436-7039-2-git-send-email-ebiederm@xmission.com> Signed-off-by: H. Peter Anvin --- arch/x86/kernel/apic/io_apic.c | 23 ++++++++++++++--------- include/linux/acpi.h | 4 ++-- 2 files changed, 16 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 127b8718abf..73ec92838d8 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -4082,22 +4082,27 @@ int __init io_apic_get_version(int ioapic) return reg_01.bits.version; } -int acpi_get_override_irq(int bus_irq, int *trigger, int *polarity) +int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity) { - int i; + int ioapic, pin, idx; if (skip_ioapic_setup) return -1; - for (i = 0; i < mp_irq_entries; i++) - if (mp_irqs[i].irqtype == mp_INT && - mp_irqs[i].srcbusirq == bus_irq) - break; - if (i >= mp_irq_entries) + ioapic = mp_find_ioapic(gsi); + if (ioapic < 0) + return -1; + + pin = mp_find_ioapic_pin(ioapic, gsi); + if (pin < 0) + return -1; + + idx = find_irq_entry(ioapic, pin, mp_INT); + if (idx < 0) return -1; - *trigger = irq_trigger(i); - *polarity = irq_polarity(i); + *trigger = irq_trigger(idx); + *polarity = irq_polarity(idx); return 0; } diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 7a937dabcc4..3da73f5f0ae 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -119,9 +119,9 @@ int acpi_gsi_to_irq (u32 gsi, unsigned int *irq); int acpi_isa_irq_to_gsi (unsigned isa_irq, u32 *gsi); #ifdef CONFIG_X86_IO_APIC -extern int acpi_get_override_irq(int bus_irq, int *trigger, int *polarity); +extern int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity); #else -#define acpi_get_override_irq(bus, trigger, polarity) (-1) +#define acpi_get_override_irq(gsi, trigger, polarity) (-1) #endif /* * This function undoes the effect of one call to acpi_register_gsi(). -- cgit v1.2.3-70-g09d2 From 2e26ca7150a4f2ab3e69471dfc65f131e7dd7a05 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 5 May 2010 10:52:31 -0400 Subject: tracing: Fix tracepoint.h DECLARE_TRACE() to allow more than one header When more than one header is included under CREATE_TRACE_POINTS the DECLARE_TRACE() macro is not defined back to its original meaning and the second include will fail to initialize the TRACE_EVENT() and DECLARE_TRACE() correctly. To fix this the tracepoint.h file moves the define of DECLARE_TRACE() out of the #ifdef _LINUX_TRACEPOINT_H protection (just like the define of the TRACE_EVENT()). This way the define_trace.h will undef the DECLARE_TRACE() at the end and allow new headers to start from scratch. This patch also requires fixing the include/events/napi.h It currently uses DECLARE_TRACE() and should be converted to a TRACE_EVENT() format. But I'll leave that change to the authors of that file. But since the napi.h file depends on using the CREATE_TRACE_POINTS and does not define its own DEFINE_TRACE() it must use the define_trace.h method instead. Cc: Neil Horman Cc: David S. Miller Cc: Mathieu Desnoyers Signed-off-by: Steven Rostedt --- include/linux/tracepoint.h | 114 ++++++++++++++++++++++--------------------- include/trace/define_trace.h | 5 ++ include/trace/events/napi.h | 10 +++- 3 files changed, 72 insertions(+), 57 deletions(-) (limited to 'include') diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 78b4bd3be49..1d85f9a6a19 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -33,6 +33,65 @@ struct tracepoint { * Keep in sync with vmlinux.lds.h. */ +/* + * Connect a probe to a tracepoint. + * Internal API, should not be used directly. + */ +extern int tracepoint_probe_register(const char *name, void *probe); + +/* + * Disconnect a probe from a tracepoint. + * Internal API, should not be used directly. + */ +extern int tracepoint_probe_unregister(const char *name, void *probe); + +extern int tracepoint_probe_register_noupdate(const char *name, void *probe); +extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe); +extern void tracepoint_probe_update_all(void); + +struct tracepoint_iter { + struct module *module; + struct tracepoint *tracepoint; +}; + +extern void tracepoint_iter_start(struct tracepoint_iter *iter); +extern void tracepoint_iter_next(struct tracepoint_iter *iter); +extern void tracepoint_iter_stop(struct tracepoint_iter *iter); +extern void tracepoint_iter_reset(struct tracepoint_iter *iter); +extern int tracepoint_get_iter_range(struct tracepoint **tracepoint, + struct tracepoint *begin, struct tracepoint *end); + +/* + * tracepoint_synchronize_unregister must be called between the last tracepoint + * probe unregistration and the end of module exit to make sure there is no + * caller executing a probe when it is freed. + */ +static inline void tracepoint_synchronize_unregister(void) +{ + synchronize_sched(); +} + +#define PARAMS(args...) args + +#ifdef CONFIG_TRACEPOINTS +extern void tracepoint_update_probe_range(struct tracepoint *begin, + struct tracepoint *end); +#else +static inline void tracepoint_update_probe_range(struct tracepoint *begin, + struct tracepoint *end) +{ } +#endif /* CONFIG_TRACEPOINTS */ + +#endif /* _LINUX_TRACEPOINT_H */ + +/* + * Note: we keep the TRACE_EVENT and DECLARE_TRACE outside the include + * file ifdef protection. + * This is due to the way trace events work. If a file includes two + * trace event headers under one "CREATE_TRACE_POINTS" the first include + * will override the TRACE_EVENT and break the second include. + */ + #ifndef DECLARE_TRACE #define TP_PROTO(args...) args @@ -96,9 +155,6 @@ struct tracepoint { #define EXPORT_TRACEPOINT_SYMBOL(name) \ EXPORT_SYMBOL(__tracepoint_##name) -extern void tracepoint_update_probe_range(struct tracepoint *begin, - struct tracepoint *end); - #else /* !CONFIG_TRACEPOINTS */ #define DECLARE_TRACE(name, proto, args) \ static inline void _do_trace_##name(struct tracepoint *tp, proto) \ @@ -119,61 +175,9 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin, #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) #define EXPORT_TRACEPOINT_SYMBOL(name) -static inline void tracepoint_update_probe_range(struct tracepoint *begin, - struct tracepoint *end) -{ } #endif /* CONFIG_TRACEPOINTS */ #endif /* DECLARE_TRACE */ -/* - * Connect a probe to a tracepoint. - * Internal API, should not be used directly. - */ -extern int tracepoint_probe_register(const char *name, void *probe); - -/* - * Disconnect a probe from a tracepoint. - * Internal API, should not be used directly. - */ -extern int tracepoint_probe_unregister(const char *name, void *probe); - -extern int tracepoint_probe_register_noupdate(const char *name, void *probe); -extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe); -extern void tracepoint_probe_update_all(void); - -struct tracepoint_iter { - struct module *module; - struct tracepoint *tracepoint; -}; - -extern void tracepoint_iter_start(struct tracepoint_iter *iter); -extern void tracepoint_iter_next(struct tracepoint_iter *iter); -extern void tracepoint_iter_stop(struct tracepoint_iter *iter); -extern void tracepoint_iter_reset(struct tracepoint_iter *iter); -extern int tracepoint_get_iter_range(struct tracepoint **tracepoint, - struct tracepoint *begin, struct tracepoint *end); - -/* - * tracepoint_synchronize_unregister must be called between the last tracepoint - * probe unregistration and the end of module exit to make sure there is no - * caller executing a probe when it is freed. - */ -static inline void tracepoint_synchronize_unregister(void) -{ - synchronize_sched(); -} - -#define PARAMS(args...) args - -#endif /* _LINUX_TRACEPOINT_H */ - -/* - * Note: we keep the TRACE_EVENT outside the include file ifdef protection. - * This is due to the way trace events work. If a file includes two - * trace event headers under one "CREATE_TRACE_POINTS" the first include - * will override the TRACE_EVENT and break the second include. - */ - #ifndef TRACE_EVENT /* * For use with the TRACE_EVENT macro: diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h index 5acfb1eb4df..1dfab540151 100644 --- a/include/trace/define_trace.h +++ b/include/trace/define_trace.h @@ -65,6 +65,10 @@ #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) +/* Make all open coded DECLARE_TRACE nops */ +#undef DECLARE_TRACE +#define DECLARE_TRACE(name, proto, args) + #ifdef CONFIG_EVENT_TRACING #include #endif @@ -75,6 +79,7 @@ #undef DEFINE_EVENT #undef DEFINE_EVENT_PRINT #undef TRACE_HEADER_MULTI_READ +#undef DECLARE_TRACE /* Only undef what we defined in this file */ #ifdef UNDEF_TRACE_INCLUDE_FILE diff --git a/include/trace/events/napi.h b/include/trace/events/napi.h index a8989c4547e..188deca2f3c 100644 --- a/include/trace/events/napi.h +++ b/include/trace/events/napi.h @@ -1,4 +1,7 @@ -#ifndef _TRACE_NAPI_H_ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM napi + +#if !defined(_TRACE_NAPI_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_NAPI_H_ #include @@ -8,4 +11,7 @@ DECLARE_TRACE(napi_poll, TP_PROTO(struct napi_struct *napi), TP_ARGS(napi)); -#endif +#endif /* _TRACE_NAPI_H_ */ + +/* This part must be outside protection */ +#include -- cgit v1.2.3-70-g09d2 From 1142d810298e694754498dbb4983fcb6cb7fd884 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 6 May 2010 18:49:20 +0200 Subject: cpu_stop: implement stop_cpu[s]() Implement a simplistic per-cpu maximum priority cpu monopolization mechanism. A non-sleeping callback can be scheduled to run on one or multiple cpus with maximum priority monopolozing those cpus. This is primarily to replace and unify RT workqueue usage in stop_machine and scheduler migration_thread which currently is serving multiple purposes. Four functions are provided - stop_one_cpu(), stop_one_cpu_nowait(), stop_cpus() and try_stop_cpus(). This is to allow clean sharing of resources among stop_cpu and all the migration thread users. One stopper thread per cpu is created which is currently named "stopper/CPU". This will eventually replace the migration thread and take on its name. * This facility was originally named cpuhog and lived in separate files but Peter Zijlstra nacked the name and thus got renamed to cpu_stop and moved into stop_machine.c. * Better reporting of preemption leak as per Peter's suggestion. Signed-off-by: Tejun Heo Acked-by: Peter Zijlstra Cc: Oleg Nesterov Cc: Dimitri Sivanich --- include/linux/stop_machine.h | 39 ++++- kernel/stop_machine.c | 372 ++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 402 insertions(+), 9 deletions(-) (limited to 'include') diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index baba3a23a81..efcbd6c3794 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -1,15 +1,46 @@ #ifndef _LINUX_STOP_MACHINE #define _LINUX_STOP_MACHINE -/* "Bogolock": stop the entire machine, disable interrupts. This is a - very heavy lock, which is equivalent to grabbing every spinlock - (and more). So the "read" side to such a lock is anything which - disables preeempt. */ + #include #include +#include #include #if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) +/* + * stop_cpu[s]() is simplistic per-cpu maximum priority cpu + * monopolization mechanism. The caller can specify a non-sleeping + * function to be executed on a single or multiple cpus preempting all + * other processes and monopolizing those cpus until it finishes. + * + * Resources for this mechanism are preallocated when a cpu is brought + * up and requests are guaranteed to be served as long as the target + * cpus are online. + */ + +typedef int (*cpu_stop_fn_t)(void *arg); + +struct cpu_stop_work { + struct list_head list; /* cpu_stopper->works */ + cpu_stop_fn_t fn; + void *arg; + struct cpu_stop_done *done; +}; + +int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg); +void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, + struct cpu_stop_work *work_buf); +int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); +int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); + +/* + * stop_machine "Bogolock": stop the entire machine, disable + * interrupts. This is a very heavy lock, which is equivalent to + * grabbing every spinlock (and more). So the "read" side to such a + * lock is anything which disables preeempt. + */ + /** * stop_machine: freeze the machine on all CPUs and run this function * @fn: the function to run diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 9bb9fb1bd79..7e3f9182aef 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -1,17 +1,379 @@ -/* Copyright 2008, 2005 Rusty Russell rusty@rustcorp.com.au IBM Corporation. - * GPL v2 and any later version. +/* + * kernel/stop_machine.c + * + * Copyright (C) 2008, 2005 IBM Corporation. + * Copyright (C) 2008, 2005 Rusty Russell rusty@rustcorp.com.au + * Copyright (C) 2010 SUSE Linux Products GmbH + * Copyright (C) 2010 Tejun Heo + * + * This file is released under the GPLv2 and any later version. */ +#include #include -#include +#include #include #include +#include #include #include -#include #include +#include #include -#include + +/* + * Structure to determine completion condition and record errors. May + * be shared by works on different cpus. + */ +struct cpu_stop_done { + atomic_t nr_todo; /* nr left to execute */ + bool executed; /* actually executed? */ + int ret; /* collected return value */ + struct completion completion; /* fired if nr_todo reaches 0 */ +}; + +/* the actual stopper, one per every possible cpu, enabled on online cpus */ +struct cpu_stopper { + spinlock_t lock; + struct list_head works; /* list of pending works */ + struct task_struct *thread; /* stopper thread */ + bool enabled; /* is this stopper enabled? */ +}; + +static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper); + +static void cpu_stop_init_done(struct cpu_stop_done *done, unsigned int nr_todo) +{ + memset(done, 0, sizeof(*done)); + atomic_set(&done->nr_todo, nr_todo); + init_completion(&done->completion); +} + +/* signal completion unless @done is NULL */ +static void cpu_stop_signal_done(struct cpu_stop_done *done, bool executed) +{ + if (done) { + if (executed) + done->executed = true; + if (atomic_dec_and_test(&done->nr_todo)) + complete(&done->completion); + } +} + +/* queue @work to @stopper. if offline, @work is completed immediately */ +static void cpu_stop_queue_work(struct cpu_stopper *stopper, + struct cpu_stop_work *work) +{ + unsigned long flags; + + spin_lock_irqsave(&stopper->lock, flags); + + if (stopper->enabled) { + list_add_tail(&work->list, &stopper->works); + wake_up_process(stopper->thread); + } else + cpu_stop_signal_done(work->done, false); + + spin_unlock_irqrestore(&stopper->lock, flags); +} + +/** + * stop_one_cpu - stop a cpu + * @cpu: cpu to stop + * @fn: function to execute + * @arg: argument to @fn + * + * Execute @fn(@arg) on @cpu. @fn is run in a process context with + * the highest priority preempting any task on the cpu and + * monopolizing it. This function returns after the execution is + * complete. + * + * This function doesn't guarantee @cpu stays online till @fn + * completes. If @cpu goes down in the middle, execution may happen + * partially or fully on different cpus. @fn should either be ready + * for that or the caller should ensure that @cpu stays online until + * this function completes. + * + * CONTEXT: + * Might sleep. + * + * RETURNS: + * -ENOENT if @fn(@arg) was not executed because @cpu was offline; + * otherwise, the return value of @fn. + */ +int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) +{ + struct cpu_stop_done done; + struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done }; + + cpu_stop_init_done(&done, 1); + cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), &work); + wait_for_completion(&done.completion); + return done.executed ? done.ret : -ENOENT; +} + +/** + * stop_one_cpu_nowait - stop a cpu but don't wait for completion + * @cpu: cpu to stop + * @fn: function to execute + * @arg: argument to @fn + * + * Similar to stop_one_cpu() but doesn't wait for completion. The + * caller is responsible for ensuring @work_buf is currently unused + * and will remain untouched until stopper starts executing @fn. + * + * CONTEXT: + * Don't care. + */ +void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, + struct cpu_stop_work *work_buf) +{ + *work_buf = (struct cpu_stop_work){ .fn = fn, .arg = arg, }; + cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), work_buf); +} + +/* static data for stop_cpus */ +static DEFINE_MUTEX(stop_cpus_mutex); +static DEFINE_PER_CPU(struct cpu_stop_work, stop_cpus_work); + +int __stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg) +{ + struct cpu_stop_work *work; + struct cpu_stop_done done; + unsigned int cpu; + + /* initialize works and done */ + for_each_cpu(cpu, cpumask) { + work = &per_cpu(stop_cpus_work, cpu); + work->fn = fn; + work->arg = arg; + work->done = &done; + } + cpu_stop_init_done(&done, cpumask_weight(cpumask)); + + /* + * Disable preemption while queueing to avoid getting + * preempted by a stopper which might wait for other stoppers + * to enter @fn which can lead to deadlock. + */ + preempt_disable(); + for_each_cpu(cpu, cpumask) + cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), + &per_cpu(stop_cpus_work, cpu)); + preempt_enable(); + + wait_for_completion(&done.completion); + return done.executed ? done.ret : -ENOENT; +} + +/** + * stop_cpus - stop multiple cpus + * @cpumask: cpus to stop + * @fn: function to execute + * @arg: argument to @fn + * + * Execute @fn(@arg) on online cpus in @cpumask. On each target cpu, + * @fn is run in a process context with the highest priority + * preempting any task on the cpu and monopolizing it. This function + * returns after all executions are complete. + * + * This function doesn't guarantee the cpus in @cpumask stay online + * till @fn completes. If some cpus go down in the middle, execution + * on the cpu may happen partially or fully on different cpus. @fn + * should either be ready for that or the caller should ensure that + * the cpus stay online until this function completes. + * + * All stop_cpus() calls are serialized making it safe for @fn to wait + * for all cpus to start executing it. + * + * CONTEXT: + * Might sleep. + * + * RETURNS: + * -ENOENT if @fn(@arg) was not executed at all because all cpus in + * @cpumask were offline; otherwise, 0 if all executions of @fn + * returned 0, any non zero return value if any returned non zero. + */ +int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg) +{ + int ret; + + /* static works are used, process one request at a time */ + mutex_lock(&stop_cpus_mutex); + ret = __stop_cpus(cpumask, fn, arg); + mutex_unlock(&stop_cpus_mutex); + return ret; +} + +/** + * try_stop_cpus - try to stop multiple cpus + * @cpumask: cpus to stop + * @fn: function to execute + * @arg: argument to @fn + * + * Identical to stop_cpus() except that it fails with -EAGAIN if + * someone else is already using the facility. + * + * CONTEXT: + * Might sleep. + * + * RETURNS: + * -EAGAIN if someone else is already stopping cpus, -ENOENT if + * @fn(@arg) was not executed at all because all cpus in @cpumask were + * offline; otherwise, 0 if all executions of @fn returned 0, any non + * zero return value if any returned non zero. + */ +int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg) +{ + int ret; + + /* static works are used, process one request at a time */ + if (!mutex_trylock(&stop_cpus_mutex)) + return -EAGAIN; + ret = __stop_cpus(cpumask, fn, arg); + mutex_unlock(&stop_cpus_mutex); + return ret; +} + +static int cpu_stopper_thread(void *data) +{ + struct cpu_stopper *stopper = data; + struct cpu_stop_work *work; + int ret; + +repeat: + set_current_state(TASK_INTERRUPTIBLE); /* mb paired w/ kthread_stop */ + + if (kthread_should_stop()) { + __set_current_state(TASK_RUNNING); + return 0; + } + + work = NULL; + spin_lock_irq(&stopper->lock); + if (!list_empty(&stopper->works)) { + work = list_first_entry(&stopper->works, + struct cpu_stop_work, list); + list_del_init(&work->list); + } + spin_unlock_irq(&stopper->lock); + + if (work) { + cpu_stop_fn_t fn = work->fn; + void *arg = work->arg; + struct cpu_stop_done *done = work->done; + char ksym_buf[KSYM_NAME_LEN]; + + __set_current_state(TASK_RUNNING); + + /* cpu stop callbacks are not allowed to sleep */ + preempt_disable(); + + ret = fn(arg); + if (ret) + done->ret = ret; + + /* restore preemption and check it's still balanced */ + preempt_enable(); + WARN_ONCE(preempt_count(), + "cpu_stop: %s(%p) leaked preempt count\n", + kallsyms_lookup((unsigned long)fn, NULL, NULL, NULL, + ksym_buf), arg); + + cpu_stop_signal_done(done, true); + } else + schedule(); + + goto repeat; +} + +/* manage stopper for a cpu, mostly lifted from sched migration thread mgmt */ +static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; + unsigned int cpu = (unsigned long)hcpu; + struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); + struct cpu_stop_work *work; + struct task_struct *p; + + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_UP_PREPARE: + BUG_ON(stopper->thread || stopper->enabled || + !list_empty(&stopper->works)); + p = kthread_create(cpu_stopper_thread, stopper, "stopper/%d", + cpu); + if (IS_ERR(p)) + return NOTIFY_BAD; + sched_setscheduler_nocheck(p, SCHED_FIFO, ¶m); + get_task_struct(p); + stopper->thread = p; + break; + + case CPU_ONLINE: + kthread_bind(stopper->thread, cpu); + /* strictly unnecessary, as first user will wake it */ + wake_up_process(stopper->thread); + /* mark enabled */ + spin_lock_irq(&stopper->lock); + stopper->enabled = true; + spin_unlock_irq(&stopper->lock); + break; + +#ifdef CONFIG_HOTPLUG_CPU + case CPU_UP_CANCELED: + case CPU_DEAD: + /* kill the stopper */ + kthread_stop(stopper->thread); + /* drain remaining works */ + spin_lock_irq(&stopper->lock); + list_for_each_entry(work, &stopper->works, list) + cpu_stop_signal_done(work->done, false); + stopper->enabled = false; + spin_unlock_irq(&stopper->lock); + /* release the stopper */ + put_task_struct(stopper->thread); + stopper->thread = NULL; + break; +#endif + } + + return NOTIFY_OK; +} + +/* + * Give it a higher priority so that cpu stopper is available to other + * cpu notifiers. It currently shares the same priority as sched + * migration_notifier. + */ +static struct notifier_block __cpuinitdata cpu_stop_cpu_notifier = { + .notifier_call = cpu_stop_cpu_callback, + .priority = 10, +}; + +static int __init cpu_stop_init(void) +{ + void *bcpu = (void *)(long)smp_processor_id(); + unsigned int cpu; + int err; + + for_each_possible_cpu(cpu) { + struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); + + spin_lock_init(&stopper->lock); + INIT_LIST_HEAD(&stopper->works); + } + + /* start one for the boot cpu */ + err = cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_UP_PREPARE, + bcpu); + BUG_ON(err == NOTIFY_BAD); + cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_ONLINE, bcpu); + register_cpu_notifier(&cpu_stop_cpu_notifier); + + return 0; +} +early_initcall(cpu_stop_init); /* This controls the threads on each CPU. */ enum stopmachine_state { -- cgit v1.2.3-70-g09d2 From 3fc1f1e27a5b807791d72e5d992aa33b668a6626 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 6 May 2010 18:49:20 +0200 Subject: stop_machine: reimplement using cpu_stop Reimplement stop_machine using cpu_stop. As cpu stoppers are guaranteed to be available for all online cpus, stop_machine_create/destroy() are no longer necessary and removed. With resource management and synchronization handled by cpu_stop, the new implementation is much simpler. Asking the cpu_stop to execute the stop_cpu() state machine on all online cpus with cpu hotplug disabled is enough. stop_machine itself doesn't need to manage any global resources anymore, so all per-instance information is rolled into struct stop_machine_data and the mutex and all static data variables are removed. The previous implementation created and destroyed RT workqueues as necessary which made stop_machine() calls highly expensive on very large machines. According to Dimitri Sivanich, preventing the dynamic creation/destruction makes booting faster more than twice on very large machines. cpu_stop resources are preallocated for all online cpus and should have the same effect. Signed-off-by: Tejun Heo Acked-by: Rusty Russell Acked-by: Peter Zijlstra Cc: Oleg Nesterov Cc: Dimitri Sivanich --- arch/s390/kernel/time.c | 1 - drivers/xen/manage.c | 14 +--- include/linux/stop_machine.h | 20 ------ kernel/cpu.c | 8 --- kernel/module.c | 14 +--- kernel/stop_machine.c | 158 +++++++++++-------------------------------- 6 files changed, 42 insertions(+), 173 deletions(-) (limited to 'include') diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index fba6dec156b..03d96569f18 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -390,7 +390,6 @@ static void __init time_init_wq(void) if (time_sync_wq) return; time_sync_wq = create_singlethread_workqueue("timesync"); - stop_machine_create(); } /* diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index 2ac4440e7b0..8943b8ccee1 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -80,12 +80,6 @@ static void do_suspend(void) shutting_down = SHUTDOWN_SUSPEND; - err = stop_machine_create(); - if (err) { - printk(KERN_ERR "xen suspend: failed to setup stop_machine %d\n", err); - goto out; - } - #ifdef CONFIG_PREEMPT /* If the kernel is preemptible, we need to freeze all the processes to prevent them from being in the middle of a pagetable update @@ -93,7 +87,7 @@ static void do_suspend(void) err = freeze_processes(); if (err) { printk(KERN_ERR "xen suspend: freeze failed %d\n", err); - goto out_destroy_sm; + goto out; } #endif @@ -136,12 +130,8 @@ out_resume: out_thaw: #ifdef CONFIG_PREEMPT thaw_processes(); - -out_destroy_sm: -#endif - stop_machine_destroy(); - out: +#endif shutting_down = SHUTDOWN_INVALID; } #endif /* CONFIG_PM_SLEEP */ diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index efcbd6c3794..0e552e72a4c 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -67,23 +67,6 @@ int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); */ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); -/** - * stop_machine_create: create all stop_machine threads - * - * Description: This causes all stop_machine threads to be created before - * stop_machine actually gets called. This can be used by subsystems that - * need a non failing stop_machine infrastructure. - */ -int stop_machine_create(void); - -/** - * stop_machine_destroy: destroy all stop_machine threads - * - * Description: This causes all stop_machine threads which were created with - * stop_machine_create to be destroyed again. - */ -void stop_machine_destroy(void); - #else static inline int stop_machine(int (*fn)(void *), void *data, @@ -96,8 +79,5 @@ static inline int stop_machine(int (*fn)(void *), void *data, return ret; } -static inline int stop_machine_create(void) { return 0; } -static inline void stop_machine_destroy(void) { } - #endif /* CONFIG_SMP */ #endif /* _LINUX_STOP_MACHINE */ diff --git a/kernel/cpu.c b/kernel/cpu.c index 914aedcde84..54577757477 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -266,9 +266,6 @@ int __ref cpu_down(unsigned int cpu) { int err; - err = stop_machine_create(); - if (err) - return err; cpu_maps_update_begin(); if (cpu_hotplug_disabled) { @@ -280,7 +277,6 @@ int __ref cpu_down(unsigned int cpu) out: cpu_maps_update_done(); - stop_machine_destroy(); return err; } EXPORT_SYMBOL(cpu_down); @@ -361,9 +357,6 @@ int disable_nonboot_cpus(void) { int cpu, first_cpu, error; - error = stop_machine_create(); - if (error) - return error; cpu_maps_update_begin(); first_cpu = cpumask_first(cpu_online_mask); /* @@ -394,7 +387,6 @@ int disable_nonboot_cpus(void) printk(KERN_ERR "Non-boot CPUs are not disabled\n"); } cpu_maps_update_done(); - stop_machine_destroy(); return error; } diff --git a/kernel/module.c b/kernel/module.c index 1016b75b026..0838246d8c9 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -723,16 +723,8 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, return -EFAULT; name[MODULE_NAME_LEN-1] = '\0'; - /* Create stop_machine threads since free_module relies on - * a non-failing stop_machine call. */ - ret = stop_machine_create(); - if (ret) - return ret; - - if (mutex_lock_interruptible(&module_mutex) != 0) { - ret = -EINTR; - goto out_stop; - } + if (mutex_lock_interruptible(&module_mutex) != 0) + return -EINTR; mod = find_module(name); if (!mod) { @@ -792,8 +784,6 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, out: mutex_unlock(&module_mutex); -out_stop: - stop_machine_destroy(); return ret; } diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 7e3f9182aef..884c7a1afee 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -388,174 +388,92 @@ enum stopmachine_state { /* Exit */ STOPMACHINE_EXIT, }; -static enum stopmachine_state state; struct stop_machine_data { - int (*fn)(void *); - void *data; - int fnret; + int (*fn)(void *); + void *data; + /* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */ + unsigned int num_threads; + const struct cpumask *active_cpus; + + enum stopmachine_state state; + atomic_t thread_ack; }; -/* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */ -static unsigned int num_threads; -static atomic_t thread_ack; -static DEFINE_MUTEX(lock); -/* setup_lock protects refcount, stop_machine_wq and stop_machine_work. */ -static DEFINE_MUTEX(setup_lock); -/* Users of stop_machine. */ -static int refcount; -static struct workqueue_struct *stop_machine_wq; -static struct stop_machine_data active, idle; -static const struct cpumask *active_cpus; -static void __percpu *stop_machine_work; - -static void set_state(enum stopmachine_state newstate) +static void set_state(struct stop_machine_data *smdata, + enum stopmachine_state newstate) { /* Reset ack counter. */ - atomic_set(&thread_ack, num_threads); + atomic_set(&smdata->thread_ack, smdata->num_threads); smp_wmb(); - state = newstate; + smdata->state = newstate; } /* Last one to ack a state moves to the next state. */ -static void ack_state(void) +static void ack_state(struct stop_machine_data *smdata) { - if (atomic_dec_and_test(&thread_ack)) - set_state(state + 1); + if (atomic_dec_and_test(&smdata->thread_ack)) + set_state(smdata, smdata->state + 1); } -/* This is the actual function which stops the CPU. It runs - * in the context of a dedicated stopmachine workqueue. */ -static void stop_cpu(struct work_struct *unused) +/* This is the cpu_stop function which stops the CPU. */ +static int stop_machine_cpu_stop(void *data) { + struct stop_machine_data *smdata = data; enum stopmachine_state curstate = STOPMACHINE_NONE; - struct stop_machine_data *smdata = &idle; - int cpu = smp_processor_id(); - int err; + int cpu = smp_processor_id(), err = 0; + bool is_active; + + if (!smdata->active_cpus) + is_active = cpu == cpumask_first(cpu_online_mask); + else + is_active = cpumask_test_cpu(cpu, smdata->active_cpus); - if (!active_cpus) { - if (cpu == cpumask_first(cpu_online_mask)) - smdata = &active; - } else { - if (cpumask_test_cpu(cpu, active_cpus)) - smdata = &active; - } /* Simple state machine */ do { /* Chill out and ensure we re-read stopmachine_state. */ cpu_relax(); - if (state != curstate) { - curstate = state; + if (smdata->state != curstate) { + curstate = smdata->state; switch (curstate) { case STOPMACHINE_DISABLE_IRQ: local_irq_disable(); hard_irq_disable(); break; case STOPMACHINE_RUN: - /* On multiple CPUs only a single error code - * is needed to tell that something failed. */ - err = smdata->fn(smdata->data); - if (err) - smdata->fnret = err; + if (is_active) + err = smdata->fn(smdata->data); break; default: break; } - ack_state(); + ack_state(smdata); } } while (curstate != STOPMACHINE_EXIT); local_irq_enable(); + return err; } -/* Callback for CPUs which aren't supposed to do anything. */ -static int chill(void *unused) -{ - return 0; -} - -int stop_machine_create(void) -{ - mutex_lock(&setup_lock); - if (refcount) - goto done; - stop_machine_wq = create_rt_workqueue("kstop"); - if (!stop_machine_wq) - goto err_out; - stop_machine_work = alloc_percpu(struct work_struct); - if (!stop_machine_work) - goto err_out; -done: - refcount++; - mutex_unlock(&setup_lock); - return 0; - -err_out: - if (stop_machine_wq) - destroy_workqueue(stop_machine_wq); - mutex_unlock(&setup_lock); - return -ENOMEM; -} -EXPORT_SYMBOL_GPL(stop_machine_create); - -void stop_machine_destroy(void) -{ - mutex_lock(&setup_lock); - refcount--; - if (refcount) - goto done; - destroy_workqueue(stop_machine_wq); - free_percpu(stop_machine_work); -done: - mutex_unlock(&setup_lock); -} -EXPORT_SYMBOL_GPL(stop_machine_destroy); - int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) { - struct work_struct *sm_work; - int i, ret; - - /* Set up initial state. */ - mutex_lock(&lock); - num_threads = num_online_cpus(); - active_cpus = cpus; - active.fn = fn; - active.data = data; - active.fnret = 0; - idle.fn = chill; - idle.data = NULL; - - set_state(STOPMACHINE_PREPARE); - - /* Schedule the stop_cpu work on all cpus: hold this CPU so one - * doesn't hit this CPU until we're ready. */ - get_cpu(); - for_each_online_cpu(i) { - sm_work = per_cpu_ptr(stop_machine_work, i); - INIT_WORK(sm_work, stop_cpu); - queue_work_on(i, stop_machine_wq, sm_work); - } - /* This will release the thread on our CPU. */ - put_cpu(); - flush_workqueue(stop_machine_wq); - ret = active.fnret; - mutex_unlock(&lock); - return ret; + struct stop_machine_data smdata = { .fn = fn, .data = data, + .num_threads = num_online_cpus(), + .active_cpus = cpus }; + + /* Set the initial state and stop all online cpus. */ + set_state(&smdata, STOPMACHINE_PREPARE); + return stop_cpus(cpu_online_mask, stop_machine_cpu_stop, &smdata); } int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) { int ret; - ret = stop_machine_create(); - if (ret) - return ret; /* No CPUs can come up or down during this. */ get_online_cpus(); ret = __stop_machine(fn, data, cpus); put_online_cpus(); - stop_machine_destroy(); return ret; } EXPORT_SYMBOL_GPL(stop_machine); -- cgit v1.2.3-70-g09d2 From 969c79215a35b06e5e3efe69b9412f858df7856c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 6 May 2010 18:49:21 +0200 Subject: sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo Acked-by: Peter Zijlstra Cc: Ingo Molnar Cc: Dipankar Sarma Cc: Josh Triplett Cc: Paul E. McKenney Cc: Oleg Nesterov Cc: Dimitri Sivanich --- Documentation/RCU/torture.txt | 10 -- include/linux/rcutiny.h | 2 - include/linux/rcutree.h | 1 - kernel/rcutorture.c | 2 +- kernel/sched.c | 315 ++++++++++++------------------------------ kernel/sched_fair.c | 48 +++++-- kernel/stop_machine.c | 2 +- 7 files changed, 127 insertions(+), 253 deletions(-) (limited to 'include') diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt index 0e50bc2aa1e..5d9016795fd 100644 --- a/Documentation/RCU/torture.txt +++ b/Documentation/RCU/torture.txt @@ -182,16 +182,6 @@ Similarly, sched_expedited RCU provides the following: sched_expedited-torture: Reader Pipe: 12660320201 95875 0 0 0 0 0 0 0 0 0 sched_expedited-torture: Reader Batch: 12660424885 0 0 0 0 0 0 0 0 0 0 sched_expedited-torture: Free-Block Circulation: 1090795 1090795 1090794 1090793 1090792 1090791 1090790 1090789 1090788 1090787 0 - state: -1 / 0:0 3:0 4:0 - -As before, the first four lines are similar to those for RCU. -The last line shows the task-migration state. The first number is --1 if synchronize_sched_expedited() is idle, -2 if in the process of -posting wakeups to the migration kthreads, and N when waiting on CPU N. -Each of the colon-separated fields following the "/" is a CPU:state pair. -Valid states are "0" for idle, "1" for waiting for quiescent state, -"2" for passed through quiescent state, and "3" when a race with a -CPU-hotplug event forces use of the synchronize_sched() primitive. USAGE diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index a5195875480..0006b2df00e 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -60,8 +60,6 @@ static inline long rcu_batches_completed_bh(void) return 0; } -extern int rcu_expedited_torture_stats(char *page); - static inline void rcu_force_quiescent_state(void) { } diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 42cc3a04779..24e467e526b 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -35,7 +35,6 @@ struct notifier_block; extern void rcu_sched_qs(int cpu); extern void rcu_bh_qs(int cpu); extern int rcu_needs_cpu(int cpu); -extern int rcu_expedited_torture_stats(char *page); #ifdef CONFIG_TREE_PREEMPT_RCU diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 58df55bf83e..2b676f3a0f2 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -669,7 +669,7 @@ static struct rcu_torture_ops sched_expedited_ops = { .sync = synchronize_sched_expedited, .cb_barrier = NULL, .fqs = rcu_sched_force_quiescent_state, - .stats = rcu_expedited_torture_stats, + .stats = NULL, .irq_capable = 1, .name = "sched_expedited" }; diff --git a/kernel/sched.c b/kernel/sched.c index 4956ed09283..f1d577a0a8a 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -55,9 +55,9 @@ #include #include #include -#include #include #include +#include #include #include #include @@ -539,15 +539,13 @@ struct rq { int post_schedule; int active_balance; int push_cpu; + struct cpu_stop_work active_balance_work; /* cpu of this runqueue: */ int cpu; int online; unsigned long avg_load_per_task; - struct task_struct *migration_thread; - struct list_head migration_queue; - u64 rt_avg; u64 age_stamp; u64 idle_stamp; @@ -2037,21 +2035,18 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) __set_task_cpu(p, new_cpu); } -struct migration_req { - struct list_head list; - +struct migration_arg { struct task_struct *task; int dest_cpu; - - struct completion done; }; +static int migration_cpu_stop(void *data); + /* * The task's runqueue lock must be held. * Returns true if you have to wait for migration thread. */ -static int -migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) +static bool migrate_task(struct task_struct *p, int dest_cpu) { struct rq *rq = task_rq(p); @@ -2059,15 +2054,7 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) * If the task is not on a runqueue (and not running), then * the next wake-up will properly place the task. */ - if (!p->se.on_rq && !task_running(rq, p)) - return 0; - - init_completion(&req->done); - req->task = p; - req->dest_cpu = dest_cpu; - list_add(&req->list, &rq->migration_queue); - - return 1; + return p->se.on_rq || task_running(rq, p); } /* @@ -3110,7 +3097,6 @@ static void update_cpu_load(struct rq *this_rq) void sched_exec(void) { struct task_struct *p = current; - struct migration_req req; unsigned long flags; struct rq *rq; int dest_cpu; @@ -3124,17 +3110,11 @@ void sched_exec(void) * select_task_rq() can race against ->cpus_allowed */ if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed) && - likely(cpu_active(dest_cpu)) && - migrate_task(p, dest_cpu, &req)) { - /* Need to wait for migration thread (might exit: take ref). */ - struct task_struct *mt = rq->migration_thread; + likely(cpu_active(dest_cpu)) && migrate_task(p, dest_cpu)) { + struct migration_arg arg = { p, dest_cpu }; - get_task_struct(mt); task_rq_unlock(rq, &flags); - wake_up_process(mt); - put_task_struct(mt); - wait_for_completion(&req.done); - + stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); return; } unlock: @@ -5290,17 +5270,15 @@ static inline void sched_init_granularity(void) /* * This is how migration works: * - * 1) we queue a struct migration_req structure in the source CPU's - * runqueue and wake up that CPU's migration thread. - * 2) we down() the locked semaphore => thread blocks. - * 3) migration thread wakes up (implicitly it forces the migrated - * thread off the CPU) - * 4) it gets the migration request and checks whether the migrated - * task is still in the wrong runqueue. - * 5) if it's in the wrong runqueue then the migration thread removes + * 1) we invoke migration_cpu_stop() on the target CPU using + * stop_one_cpu(). + * 2) stopper starts to run (implicitly forcing the migrated thread + * off the CPU) + * 3) it checks whether the migrated task is still in the wrong runqueue. + * 4) if it's in the wrong runqueue then the migration thread removes * it and puts it into the right queue. - * 6) migration thread up()s the semaphore. - * 7) we wake up and the migration is done. + * 5) stopper completes and stop_one_cpu() returns and the migration + * is done. */ /* @@ -5314,9 +5292,9 @@ static inline void sched_init_granularity(void) */ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) { - struct migration_req req; unsigned long flags; struct rq *rq; + unsigned int dest_cpu; int ret = 0; /* @@ -5354,15 +5332,12 @@ again: if (cpumask_test_cpu(task_cpu(p), new_mask)) goto out; - if (migrate_task(p, cpumask_any_and(cpu_active_mask, new_mask), &req)) { + dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); + if (migrate_task(p, dest_cpu)) { + struct migration_arg arg = { p, dest_cpu }; /* Need help from migration thread: drop lock and wait. */ - struct task_struct *mt = rq->migration_thread; - - get_task_struct(mt); task_rq_unlock(rq, &flags); - wake_up_process(mt); - put_task_struct(mt); - wait_for_completion(&req.done); + stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); tlb_migrate_finish(p->mm); return 0; } @@ -5420,70 +5395,22 @@ fail: return ret; } -#define RCU_MIGRATION_IDLE 0 -#define RCU_MIGRATION_NEED_QS 1 -#define RCU_MIGRATION_GOT_QS 2 -#define RCU_MIGRATION_MUST_SYNC 3 - /* - * migration_thread - this is a highprio system thread that performs - * thread migration by bumping thread off CPU then 'pushing' onto - * another runqueue. + * migration_cpu_stop - this will be executed by a highprio stopper thread + * and performs thread migration by bumping thread off CPU then + * 'pushing' onto another runqueue. */ -static int migration_thread(void *data) +static int migration_cpu_stop(void *data) { - int badcpu; - int cpu = (long)data; - struct rq *rq; - - rq = cpu_rq(cpu); - BUG_ON(rq->migration_thread != current); - - set_current_state(TASK_INTERRUPTIBLE); - while (!kthread_should_stop()) { - struct migration_req *req; - struct list_head *head; - - raw_spin_lock_irq(&rq->lock); - - if (cpu_is_offline(cpu)) { - raw_spin_unlock_irq(&rq->lock); - break; - } - - if (rq->active_balance) { - active_load_balance(rq, cpu); - rq->active_balance = 0; - } - - head = &rq->migration_queue; - - if (list_empty(head)) { - raw_spin_unlock_irq(&rq->lock); - schedule(); - set_current_state(TASK_INTERRUPTIBLE); - continue; - } - req = list_entry(head->next, struct migration_req, list); - list_del_init(head->next); - - if (req->task != NULL) { - raw_spin_unlock(&rq->lock); - __migrate_task(req->task, cpu, req->dest_cpu); - } else if (likely(cpu == (badcpu = smp_processor_id()))) { - req->dest_cpu = RCU_MIGRATION_GOT_QS; - raw_spin_unlock(&rq->lock); - } else { - req->dest_cpu = RCU_MIGRATION_MUST_SYNC; - raw_spin_unlock(&rq->lock); - WARN_ONCE(1, "migration_thread() on CPU %d, expected %d\n", badcpu, cpu); - } - local_irq_enable(); - - complete(&req->done); - } - __set_current_state(TASK_RUNNING); + struct migration_arg *arg = data; + /* + * The original target cpu might have gone down and we might + * be on another cpu but it doesn't matter. + */ + local_irq_disable(); + __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); + local_irq_enable(); return 0; } @@ -5850,35 +5777,20 @@ static void set_rq_offline(struct rq *rq) static int __cpuinit migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) { - struct task_struct *p; int cpu = (long)hcpu; unsigned long flags; - struct rq *rq; + struct rq *rq = cpu_rq(cpu); switch (action) { case CPU_UP_PREPARE: case CPU_UP_PREPARE_FROZEN: - p = kthread_create(migration_thread, hcpu, "migration/%d", cpu); - if (IS_ERR(p)) - return NOTIFY_BAD; - kthread_bind(p, cpu); - /* Must be high prio: stop_machine expects to yield to it. */ - rq = task_rq_lock(p, &flags); - __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); - task_rq_unlock(rq, &flags); - get_task_struct(p); - cpu_rq(cpu)->migration_thread = p; rq->calc_load_update = calc_load_update; break; case CPU_ONLINE: case CPU_ONLINE_FROZEN: - /* Strictly unnecessary, as first user will wake it. */ - wake_up_process(cpu_rq(cpu)->migration_thread); - /* Update our root-domain */ - rq = cpu_rq(cpu); raw_spin_lock_irqsave(&rq->lock, flags); if (rq->rd) { BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); @@ -5889,25 +5801,9 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) break; #ifdef CONFIG_HOTPLUG_CPU - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - if (!cpu_rq(cpu)->migration_thread) - break; - /* Unbind it from offline cpu so it can run. Fall thru. */ - kthread_bind(cpu_rq(cpu)->migration_thread, - cpumask_any(cpu_online_mask)); - kthread_stop(cpu_rq(cpu)->migration_thread); - put_task_struct(cpu_rq(cpu)->migration_thread); - cpu_rq(cpu)->migration_thread = NULL; - break; - case CPU_DEAD: case CPU_DEAD_FROZEN: migrate_live_tasks(cpu); - rq = cpu_rq(cpu); - kthread_stop(rq->migration_thread); - put_task_struct(rq->migration_thread); - rq->migration_thread = NULL; /* Idle task back to normal (off runqueue, low prio) */ raw_spin_lock_irq(&rq->lock); deactivate_task(rq, rq->idle, 0); @@ -5918,29 +5814,11 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) migrate_nr_uninterruptible(rq); BUG_ON(rq->nr_running != 0); calc_global_load_remove(rq); - /* - * No need to migrate the tasks: it was best-effort if - * they didn't take sched_hotcpu_mutex. Just wake up - * the requestors. - */ - raw_spin_lock_irq(&rq->lock); - while (!list_empty(&rq->migration_queue)) { - struct migration_req *req; - - req = list_entry(rq->migration_queue.next, - struct migration_req, list); - list_del_init(&req->list); - raw_spin_unlock_irq(&rq->lock); - complete(&req->done); - raw_spin_lock_irq(&rq->lock); - } - raw_spin_unlock_irq(&rq->lock); break; case CPU_DYING: case CPU_DYING_FROZEN: /* Update our root-domain */ - rq = cpu_rq(cpu); raw_spin_lock_irqsave(&rq->lock, flags); if (rq->rd) { BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); @@ -7757,10 +7635,8 @@ void __init sched_init(void) rq->push_cpu = 0; rq->cpu = i; rq->online = 0; - rq->migration_thread = NULL; rq->idle_stamp = 0; rq->avg_idle = 2*sysctl_sched_migration_cost; - INIT_LIST_HEAD(&rq->migration_queue); rq_attach_root(rq, &def_root_domain); #endif init_rq_hrtick(rq); @@ -9054,43 +8930,39 @@ struct cgroup_subsys cpuacct_subsys = { #ifndef CONFIG_SMP -int rcu_expedited_torture_stats(char *page) -{ - return 0; -} -EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); - void synchronize_sched_expedited(void) { + /* + * There must be a full memory barrier on each affected CPU + * between the time that try_stop_cpus() is called and the + * time that it returns. + * + * In the current initial implementation of cpu_stop, the + * above condition is already met when the control reaches + * this point and the following smp_mb() is not strictly + * necessary. Do smp_mb() anyway for documentation and + * robustness against future implementation changes. + */ + smp_mb(); } EXPORT_SYMBOL_GPL(synchronize_sched_expedited); #else /* #ifndef CONFIG_SMP */ -static DEFINE_PER_CPU(struct migration_req, rcu_migration_req); -static DEFINE_MUTEX(rcu_sched_expedited_mutex); - -#define RCU_EXPEDITED_STATE_POST -2 -#define RCU_EXPEDITED_STATE_IDLE -1 +static atomic_t synchronize_sched_expedited_count = ATOMIC_INIT(0); -static int rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; - -int rcu_expedited_torture_stats(char *page) +static int synchronize_sched_expedited_cpu_stop(void *data) { - int cnt = 0; - int cpu; + static DEFINE_SPINLOCK(done_mask_lock); + struct cpumask *done_mask = data; - cnt += sprintf(&page[cnt], "state: %d /", rcu_expedited_state); - for_each_online_cpu(cpu) { - cnt += sprintf(&page[cnt], " %d:%d", - cpu, per_cpu(rcu_migration_req, cpu).dest_cpu); + if (done_mask) { + spin_lock(&done_mask_lock); + cpumask_set_cpu(smp_processor_id(), done_mask); + spin_unlock(&done_mask_lock); } - cnt += sprintf(&page[cnt], "\n"); - return cnt; + return 0; } -EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); - -static long synchronize_sched_expedited_count; /* * Wait for an rcu-sched grace period to elapse, but use "big hammer" @@ -9104,60 +8976,55 @@ static long synchronize_sched_expedited_count; */ void synchronize_sched_expedited(void) { - int cpu; - unsigned long flags; - bool need_full_sync = 0; - struct rq *rq; - struct migration_req *req; - long snap; - int trycount = 0; + cpumask_var_t done_mask_var; + struct cpumask *done_mask = NULL; + int snap, trycount = 0; + + /* + * done_mask is used to check that all cpus actually have + * finished running the stopper, which is guaranteed by + * stop_cpus() if it's called with cpu hotplug blocked. Keep + * the paranoia for now but it's best effort if cpumask is off + * stack. + */ + if (zalloc_cpumask_var(&done_mask_var, GFP_ATOMIC)) + done_mask = done_mask_var; smp_mb(); /* ensure prior mod happens before capturing snap. */ - snap = ACCESS_ONCE(synchronize_sched_expedited_count) + 1; + snap = atomic_read(&synchronize_sched_expedited_count) + 1; get_online_cpus(); - while (!mutex_trylock(&rcu_sched_expedited_mutex)) { + while (try_stop_cpus(cpu_online_mask, + synchronize_sched_expedited_cpu_stop, + done_mask) == -EAGAIN) { put_online_cpus(); if (trycount++ < 10) udelay(trycount * num_online_cpus()); else { synchronize_sched(); - return; + goto free_out; } - if (ACCESS_ONCE(synchronize_sched_expedited_count) - snap > 0) { + if (atomic_read(&synchronize_sched_expedited_count) - snap > 0) { smp_mb(); /* ensure test happens before caller kfree */ - return; + goto free_out; } get_online_cpus(); } - rcu_expedited_state = RCU_EXPEDITED_STATE_POST; - for_each_online_cpu(cpu) { - rq = cpu_rq(cpu); - req = &per_cpu(rcu_migration_req, cpu); - init_completion(&req->done); - req->task = NULL; - req->dest_cpu = RCU_MIGRATION_NEED_QS; - raw_spin_lock_irqsave(&rq->lock, flags); - list_add(&req->list, &rq->migration_queue); - raw_spin_unlock_irqrestore(&rq->lock, flags); - wake_up_process(rq->migration_thread); - } - for_each_online_cpu(cpu) { - rcu_expedited_state = cpu; - req = &per_cpu(rcu_migration_req, cpu); - rq = cpu_rq(cpu); - wait_for_completion(&req->done); - raw_spin_lock_irqsave(&rq->lock, flags); - if (unlikely(req->dest_cpu == RCU_MIGRATION_MUST_SYNC)) - need_full_sync = 1; - req->dest_cpu = RCU_MIGRATION_IDLE; - raw_spin_unlock_irqrestore(&rq->lock, flags); - } - rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; - synchronize_sched_expedited_count++; - mutex_unlock(&rcu_sched_expedited_mutex); + atomic_inc(&synchronize_sched_expedited_count); + if (done_mask) + cpumask_xor(done_mask, done_mask, cpu_online_mask); put_online_cpus(); - if (need_full_sync) + + /* paranoia - this can't happen */ + if (done_mask && cpumask_weight(done_mask)) { + char buf[80]; + + cpulist_scnprintf(buf, sizeof(buf), done_mask); + WARN_ONCE(1, "synchronize_sched_expedited: cpu online and done masks disagree on %d cpus: %s\n", + cpumask_weight(done_mask), buf); synchronize_sched(); + } +free_out: + free_cpumask_var(done_mask_var); } EXPORT_SYMBOL_GPL(synchronize_sched_expedited); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index cbd8b8a296d..217e4a9393e 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -2798,6 +2798,8 @@ static int need_active_balance(struct sched_domain *sd, int sd_idle, int idle) return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2); } +static int active_load_balance_cpu_stop(void *data); + /* * Check this_cpu to ensure it is balanced within domain. Attempt to move * tasks if there is an imbalance. @@ -2887,8 +2889,9 @@ redo: if (need_active_balance(sd, sd_idle, idle)) { raw_spin_lock_irqsave(&busiest->lock, flags); - /* don't kick the migration_thread, if the curr - * task on busiest cpu can't be moved to this_cpu + /* don't kick the active_load_balance_cpu_stop, + * if the curr task on busiest cpu can't be + * moved to this_cpu */ if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) { @@ -2898,14 +2901,22 @@ redo: goto out_one_pinned; } + /* + * ->active_balance synchronizes accesses to + * ->active_balance_work. Once set, it's cleared + * only after active load balance is finished. + */ if (!busiest->active_balance) { busiest->active_balance = 1; busiest->push_cpu = this_cpu; active_balance = 1; } raw_spin_unlock_irqrestore(&busiest->lock, flags); + if (active_balance) - wake_up_process(busiest->migration_thread); + stop_one_cpu_nowait(cpu_of(busiest), + active_load_balance_cpu_stop, busiest, + &busiest->active_balance_work); /* * We've kicked active balancing, reset the failure @@ -3012,24 +3023,29 @@ static void idle_balance(int this_cpu, struct rq *this_rq) } /* - * active_load_balance is run by migration threads. It pushes running tasks - * off the busiest CPU onto idle CPUs. It requires at least 1 task to be - * running on each physical CPU where possible, and avoids physical / - * logical imbalances. - * - * Called with busiest_rq locked. + * active_load_balance_cpu_stop is run by cpu stopper. It pushes + * running tasks off the busiest CPU onto idle CPUs. It requires at + * least 1 task to be running on each physical CPU where possible, and + * avoids physical / logical imbalances. */ -static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) +static int active_load_balance_cpu_stop(void *data) { + struct rq *busiest_rq = data; + int busiest_cpu = cpu_of(busiest_rq); int target_cpu = busiest_rq->push_cpu; + struct rq *target_rq = cpu_rq(target_cpu); struct sched_domain *sd; - struct rq *target_rq; + + raw_spin_lock_irq(&busiest_rq->lock); + + /* make sure the requested cpu hasn't gone down in the meantime */ + if (unlikely(busiest_cpu != smp_processor_id() || + !busiest_rq->active_balance)) + goto out_unlock; /* Is there any task to move? */ if (busiest_rq->nr_running <= 1) - return; - - target_rq = cpu_rq(target_cpu); + goto out_unlock; /* * This condition is "impossible", if it occurs @@ -3058,6 +3074,10 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) schedstat_inc(sd, alb_failed); } double_unlock_balance(busiest_rq, target_rq); +out_unlock: + busiest_rq->active_balance = 0; + raw_spin_unlock_irq(&busiest_rq->lock); + return 0; } #ifdef CONFIG_NO_HZ diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 884c7a1afee..5b20141a5ec 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -301,7 +301,7 @@ static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb, case CPU_UP_PREPARE: BUG_ON(stopper->thread || stopper->enabled || !list_empty(&stopper->works)); - p = kthread_create(cpu_stopper_thread, stopper, "stopper/%d", + p = kthread_create(cpu_stopper_thread, stopper, "migration/%d", cpu); if (IS_ERR(p)) return NOTIFY_BAD; -- cgit v1.2.3-70-g09d2 From 27a9da6538ee18046d7bff8e36a9f783542c54c3 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 4 May 2010 20:36:56 +0200 Subject: sched: Remove rq argument to the tracepoints struct rq isn't visible outside of sched.o so its near useless to expose the pointer, also there are no users of it, so remove it. Acked-by: Steven Rostedt Signed-off-by: Peter Zijlstra LKML-Reference: <1272997616.1642.207.camel@laptop> Signed-off-by: Ingo Molnar --- include/trace/events/sched.h | 32 ++++++++++---------------------- kernel/sched.c | 8 ++++---- kernel/trace/ftrace.c | 3 +-- kernel/trace/trace_sched_switch.c | 5 ++--- kernel/trace/trace_sched_wakeup.c | 5 ++--- 5 files changed, 19 insertions(+), 34 deletions(-) (limited to 'include') diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index cfceb0b73e2..4f733ecea46 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -51,15 +51,12 @@ TRACE_EVENT(sched_kthread_stop_ret, /* * Tracepoint for waiting on task to unschedule: - * - * (NOTE: the 'rq' argument is not used by generic trace events, - * but used by the latency tracer plugin. ) */ TRACE_EVENT(sched_wait_task, - TP_PROTO(struct rq *rq, struct task_struct *p), + TP_PROTO(struct task_struct *p), - TP_ARGS(rq, p), + TP_ARGS(p), TP_STRUCT__entry( __array( char, comm, TASK_COMM_LEN ) @@ -79,15 +76,12 @@ TRACE_EVENT(sched_wait_task, /* * Tracepoint for waking up a task: - * - * (NOTE: the 'rq' argument is not used by generic trace events, - * but used by the latency tracer plugin. ) */ DECLARE_EVENT_CLASS(sched_wakeup_template, - TP_PROTO(struct rq *rq, struct task_struct *p, int success), + TP_PROTO(struct task_struct *p, int success), - TP_ARGS(rq, p, success), + TP_ARGS(p, success), TP_STRUCT__entry( __array( char, comm, TASK_COMM_LEN ) @@ -111,31 +105,25 @@ DECLARE_EVENT_CLASS(sched_wakeup_template, ); DEFINE_EVENT(sched_wakeup_template, sched_wakeup, - TP_PROTO(struct rq *rq, struct task_struct *p, int success), - TP_ARGS(rq, p, success)); + TP_PROTO(struct task_struct *p, int success), + TP_ARGS(p, success)); /* * Tracepoint for waking up a new task: - * - * (NOTE: the 'rq' argument is not used by generic trace events, - * but used by the latency tracer plugin. ) */ DEFINE_EVENT(sched_wakeup_template, sched_wakeup_new, - TP_PROTO(struct rq *rq, struct task_struct *p, int success), - TP_ARGS(rq, p, success)); + TP_PROTO(struct task_struct *p, int success), + TP_ARGS(p, success)); /* * Tracepoint for task switches, performed by the scheduler: - * - * (NOTE: the 'rq' argument is not used by generic trace events, - * but used by the latency tracer plugin. ) */ TRACE_EVENT(sched_switch, - TP_PROTO(struct rq *rq, struct task_struct *prev, + TP_PROTO(struct task_struct *prev, struct task_struct *next), - TP_ARGS(rq, prev, next), + TP_ARGS(prev, next), TP_STRUCT__entry( __array( char, prev_comm, TASK_COMM_LEN ) diff --git a/kernel/sched.c b/kernel/sched.c index 4956ed09283..11ac0eb0bce 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2168,7 +2168,7 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state) * just go back and repeat. */ rq = task_rq_lock(p, &flags); - trace_sched_wait_task(rq, p); + trace_sched_wait_task(p); running = task_running(rq, p); on_rq = p->se.on_rq; ncsw = 0; @@ -2439,7 +2439,7 @@ out_activate: success = 1; out_running: - trace_sched_wakeup(rq, p, success); + trace_sched_wakeup(p, success); check_preempt_curr(rq, p, wake_flags); p->state = TASK_RUNNING; @@ -2613,7 +2613,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) rq = task_rq_lock(p, &flags); activate_task(rq, p, 0); - trace_sched_wakeup_new(rq, p, 1); + trace_sched_wakeup_new(p, 1); check_preempt_curr(rq, p, WF_FORK); #ifdef CONFIG_SMP if (p->sched_class->task_woken) @@ -2833,7 +2833,7 @@ context_switch(struct rq *rq, struct task_struct *prev, struct mm_struct *mm, *oldmm; prepare_task_switch(rq, prev, next); - trace_sched_switch(rq, prev, next); + trace_sched_switch(prev, next); mm = next->mm; oldmm = prev->active_mm; /* diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 2404b59b309..aa3a92b511e 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3212,8 +3212,7 @@ free: } static void -ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, - struct task_struct *next) +ftrace_graph_probe_sched_switch(struct task_struct *prev, struct task_struct *next) { unsigned long long timestamp; int index; diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 5fca0f51fde..a55fccfede5 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -50,8 +50,7 @@ tracing_sched_switch_trace(struct trace_array *tr, } static void -probe_sched_switch(struct rq *__rq, struct task_struct *prev, - struct task_struct *next) +probe_sched_switch(struct task_struct *prev, struct task_struct *next) { struct trace_array_cpu *data; unsigned long flags; @@ -109,7 +108,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr, } static void -probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee, int success) +probe_sched_wakeup(struct task_struct *wakee, int success) { struct trace_array_cpu *data; unsigned long flags; diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 0271742abb8..8052446ceea 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -107,8 +107,7 @@ static void probe_wakeup_migrate_task(struct task_struct *task, int cpu) } static void notrace -probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, - struct task_struct *next) +probe_wakeup_sched_switch(struct task_struct *prev, struct task_struct *next) { struct trace_array_cpu *data; cycle_t T0, T1, delta; @@ -200,7 +199,7 @@ static void wakeup_reset(struct trace_array *tr) } static void -probe_wakeup(struct rq *rq, struct task_struct *p, int success) +probe_wakeup(struct task_struct *p, int success) { struct trace_array_cpu *data; int cpu = smp_processor_id(); -- cgit v1.2.3-70-g09d2 From 4fd38e4595e2f6c9d27732c042a0e16b2753049c Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 6 May 2010 17:31:38 +0200 Subject: perf: Fix exit() vs PERF_FORMAT_GROUP Both Stephane and Corey reported that PERF_FORMAT_GROUP didn't work as expected if the task the counters were attached to quit before the read() call. The cause is that we unconditionally destroy the grouping when we remove counters from their context. Fix this by only doing this when we free the counter itself. Reported-by: Corey Ashford Reported-by: Stephane Eranian Signed-off-by: Peter Zijlstra LKML-Reference: <1273160566.5605.404.camel@twins> Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 1 + kernel/perf_event.c | 5 +++++ 2 files changed, 6 insertions(+) (limited to 'include') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index c8e37544040..bf8f3c00329 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -522,6 +522,7 @@ struct pmu { * enum perf_event_active_state - the states of a event */ enum perf_event_active_state { + PERF_EVENT_STATE_FREE = -3, PERF_EVENT_STATE_ERROR = -2, PERF_EVENT_STATE_OFF = -1, PERF_EVENT_STATE_INACTIVE = 0, diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 3d1552d3c12..f13c3db765f 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -341,6 +341,9 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) if (event->state > PERF_EVENT_STATE_OFF) event->state = PERF_EVENT_STATE_OFF; + if (event->state > PERF_EVENT_STATE_FREE) + return; + /* * If this was a group event with sibling events then * upgrade the siblings to singleton events by adding them @@ -1856,6 +1859,8 @@ int perf_event_release_kernel(struct perf_event *event) { struct perf_event_context *ctx = event->ctx; + event->state = PERF_EVENT_STATE_FREE; + WARN_ON_ONCE(ctx->parent_ctx); mutex_lock(&ctx->mutex); perf_event_remove_from_context(event); -- cgit v1.2.3-70-g09d2 From ab608344bcbde4f55ec4cd911b686b0ce3eae076 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 8 Apr 2010 23:03:20 +0200 Subject: perf, x86: Improve the PEBS ABI Rename perf_event_attr::precise to perf_event_attr::precise_ip and widen it to 2 bits. This new field describes the required precision of the PERF_SAMPLE_IP field: 0 - SAMPLE_IP can have arbitrary skid 1 - SAMPLE_IP must have constant skid 2 - SAMPLE_IP requested to have 0 skid 3 - SAMPLE_IP must have 0 skid And modify the Intel PEBS code accordingly. The PEBS implementation now supports up to precise_ip == 2, where we perform the IP fixup. Also s/PERF_RECORD_MISC_EXACT/&_IP/ to clarify its meaning, this bit should be set for each PERF_SAMPLE_IP field known to match the actual instruction triggering the event. This new scheme allows for a PEBS mode that uses the buffer for more than a single event. Signed-off-by: Peter Zijlstra Cc: Paul Mackerras Cc: Stephane Eranian LKML-Reference: Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.c | 17 ++++++++++++++++- arch/x86/kernel/cpu/perf_event_intel.c | 4 ++-- arch/x86/kernel/cpu/perf_event_intel_ds.c | 12 ++++++------ include/linux/perf_event.h | 23 +++++++++++++++++++---- tools/perf/builtin-top.c | 2 +- tools/perf/util/parse-events.c | 25 ++++++++++++++++--------- 6 files changed, 60 insertions(+), 23 deletions(-) (limited to 'include') diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 4a3f1f2b9b9..27fa9eeed02 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -488,6 +488,21 @@ static int x86_setup_perfctr(struct perf_event *event) static int x86_pmu_hw_config(struct perf_event *event) { + if (event->attr.precise_ip) { + int precise = 0; + + /* Support for constant skid */ + if (x86_pmu.pebs) + precise++; + + /* Support for IP fixup */ + if (x86_pmu.lbr_nr) + precise++; + + if (event->attr.precise_ip > precise) + return -EOPNOTSUPP; + } + /* * Generate PMC IRQs: * (keep 'enabled' bit clear for now) @@ -1780,7 +1795,7 @@ unsigned long perf_misc_flags(struct pt_regs *regs) } if (regs->flags & PERF_EFLAGS_EXACT) - misc |= PERF_RECORD_MISC_EXACT; + misc |= PERF_RECORD_MISC_EXACT_IP; return misc; } diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index a4b56ac425c..fdbc652d3fe 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -563,7 +563,7 @@ static void intel_pmu_disable_event(struct perf_event *event) x86_pmu_disable_event(event); - if (unlikely(event->attr.precise)) + if (unlikely(event->attr.precise_ip)) intel_pmu_pebs_disable(event); } @@ -615,7 +615,7 @@ static void intel_pmu_enable_event(struct perf_event *event) return; } - if (unlikely(event->attr.precise)) + if (unlikely(event->attr.precise_ip)) intel_pmu_pebs_enable(event); __x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE); diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c index 35056f715e9..18018d1311c 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -307,7 +307,7 @@ intel_pebs_constraints(struct perf_event *event) { struct event_constraint *c; - if (!event->attr.precise) + if (!event->attr.precise_ip) return NULL; if (x86_pmu.pebs_constraints) { @@ -330,7 +330,7 @@ static void intel_pmu_pebs_enable(struct perf_event *event) cpuc->pebs_enabled |= 1ULL << hwc->idx; WARN_ON_ONCE(cpuc->enabled); - if (x86_pmu.intel_cap.pebs_trap) + if (x86_pmu.intel_cap.pebs_trap && event->attr.precise_ip > 1) intel_pmu_lbr_enable(event); } @@ -345,7 +345,7 @@ static void intel_pmu_pebs_disable(struct perf_event *event) hwc->config |= ARCH_PERFMON_EVENTSEL_INT; - if (x86_pmu.intel_cap.pebs_trap) + if (x86_pmu.intel_cap.pebs_trap && event->attr.precise_ip > 1) intel_pmu_lbr_disable(event); } @@ -485,7 +485,7 @@ static void __intel_pmu_pebs_event(struct perf_event *event, regs.bp = pebs->bp; regs.sp = pebs->sp; - if (intel_pmu_pebs_fixup_ip(regs)) + if (event->attr.precise_ip > 1 && intel_pmu_pebs_fixup_ip(®s)) regs.flags |= PERF_EFLAGS_EXACT; else regs.flags &= ~PERF_EFLAGS_EXACT; @@ -518,7 +518,7 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs) WARN_ON_ONCE(!event); - if (!event->attr.precise) + if (!event->attr.precise_ip) return; n = top - at; @@ -570,7 +570,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) WARN_ON_ONCE(!event); - if (!event->attr.precise) + if (!event->attr.precise_ip) continue; if (__test_and_set_bit(bit, (unsigned long *)&status)) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 6be4a0f9137..23cd0057a68 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -203,9 +203,19 @@ struct perf_event_attr { enable_on_exec : 1, /* next exec enables */ task : 1, /* trace fork/exit */ watermark : 1, /* wakeup_watermark */ - precise : 1, /* OoO invariant counter */ - - __reserved_1 : 48; + /* + * precise_ip: + * + * 0 - SAMPLE_IP can have arbitrary skid + * 1 - SAMPLE_IP must have constant skid + * 2 - SAMPLE_IP requested to have 0 skid + * 3 - SAMPLE_IP must have 0 skid + * + * See also PERF_RECORD_MISC_EXACT_IP + */ + precise_ip : 2, /* skid constraint */ + + __reserved_1 : 47; union { __u32 wakeup_events; /* wakeup every n events */ @@ -296,7 +306,12 @@ struct perf_event_mmap_page { #define PERF_RECORD_MISC_GUEST_KERNEL (4 << 0) #define PERF_RECORD_MISC_GUEST_USER (5 << 0) -#define PERF_RECORD_MISC_EXACT (1 << 14) +/* + * Indicates that the content of PERF_SAMPLE_IP points to + * the actual instruction that triggered the event. See also + * perf_event_attr::precise_ip. + */ +#define PERF_RECORD_MISC_EXACT_IP (1 << 14) /* * Reserve the last bit to indicate some extended misc field */ diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 3de397764cb..ed9b5b6905f 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -1021,7 +1021,7 @@ static void event__process_sample(const event_t *self, return; } - if (self->header.misc & PERF_RECORD_MISC_EXACT) + if (self->header.misc & PERF_RECORD_MISC_EXACT_IP) exact_samples++; if (event__preprocess_sample(self, session, &al, symbol_filter) < 0 || diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index bc8b7e61420..ae7f5917935 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -654,10 +654,6 @@ parse_raw_event(const char **strp, struct perf_event_attr *attr) return EVT_FAILED; n = hex2u64(str + 1, &config); if (n > 0) { - if (str[n+1] == 'p') { - attr->precise = 1; - n++; - } *strp = str + n + 1; attr->type = PERF_TYPE_RAW; attr->config = config; @@ -692,19 +688,29 @@ static enum event_result parse_event_modifier(const char **strp, struct perf_event_attr *attr) { const char *str = *strp; - int eu = 1, ek = 1, eh = 1; + int exclude = 0; + int eu = 0, ek = 0, eh = 0, precise = 0; if (*str++ != ':') return 0; while (*str) { - if (*str == 'u') + if (*str == 'u') { + if (!exclude) + exclude = eu = ek = eh = 1; eu = 0; - else if (*str == 'k') + } else if (*str == 'k') { + if (!exclude) + exclude = eu = ek = eh = 1; ek = 0; - else if (*str == 'h') + } else if (*str == 'h') { + if (!exclude) + exclude = eu = ek = eh = 1; eh = 0; - else + } else if (*str == 'p') { + precise++; + } else break; + ++str; } if (str >= *strp + 2) { @@ -712,6 +718,7 @@ parse_event_modifier(const char **strp, struct perf_event_attr *attr) attr->exclude_user = eu; attr->exclude_kernel = ek; attr->exclude_hv = eh; + attr->precise_ip = precise; return 1; } return 0; -- cgit v1.2.3-70-g09d2 From 6bde9b6ce0127e2a56228a2071536d422be31336 Mon Sep 17 00:00:00 2001 From: Lin Ming Date: Fri, 23 Apr 2010 13:56:00 +0800 Subject: perf: Add group scheduling transactional APIs Add group scheduling transactional APIs to struct pmu. These APIs will be implemented in arch code, based on Peter's idea as below. > the idea behind hw_perf_group_sched_in() is to not perform > schedulability tests on each event in the group, but to add the group > as a whole and then perform one test. > > Of course, when that test fails, you'll have to roll-back the whole > group again. > > So start_txn (or a better name) would simply toggle a flag in the pmu > implementation that will make pmu::enable() not perform the > schedulablilty test. > > Then commit_txn() will perform the schedulability test (so note the > method has to have a !void return value. > > This will allow us to use the regular > kernel/perf_event.c::group_sched_in() and all the rollback code. > Currently each hw_perf_group_sched_in() implementation duplicates all > the rolllback code (with various bugs). ->start_txn: Start group events scheduling transaction, set a flag to make pmu::enable() not perform the schedulability test, it will be performed at commit time. ->commit_txn: Commit group events scheduling transaction, perform the group schedulability as a whole ->cancel_txn: Stop group events scheduling transaction, clear the flag so pmu::enable() will perform the schedulability test. Reviewed-by: Stephane Eranian Reviewed-by: Frederic Weisbecker Signed-off-by: Lin Ming Cc: David Miller Cc: Paul Mackerras Signed-off-by: Peter Zijlstra LKML-Reference: <1272002160.5707.60.camel@minggr.sh.intel.com> Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 15 ++++++++++++--- kernel/perf_event.c | 33 ++++++++++++++++++++------------- 2 files changed, 32 insertions(+), 16 deletions(-) (limited to 'include') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 23cd0057a68..4924c96d7e2 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -547,6 +547,8 @@ struct hw_perf_event { struct perf_event; +#define PERF_EVENT_TXN_STARTED 1 + /** * struct pmu - generic performance monitoring unit */ @@ -557,6 +559,16 @@ struct pmu { void (*stop) (struct perf_event *event); void (*read) (struct perf_event *event); void (*unthrottle) (struct perf_event *event); + + /* + * group events scheduling is treated as a transaction, + * add group events as a whole and perform one schedulability test. + * If test fails, roll back the whole group + */ + + void (*start_txn) (const struct pmu *pmu); + void (*cancel_txn) (const struct pmu *pmu); + int (*commit_txn) (const struct pmu *pmu); }; /** @@ -823,9 +835,6 @@ extern void perf_disable(void); extern void perf_enable(void); extern int perf_event_task_disable(void); extern int perf_event_task_enable(void); -extern int hw_perf_group_sched_in(struct perf_event *group_leader, - struct perf_cpu_context *cpuctx, - struct perf_event_context *ctx); extern void perf_event_update_userpage(struct perf_event *event); extern int perf_event_release_kernel(struct perf_event *event); extern struct perf_event * diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 34659d4085c..bb06382f98e 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -83,14 +83,6 @@ extern __weak const struct pmu *hw_perf_event_init(struct perf_event *event) void __weak hw_perf_disable(void) { barrier(); } void __weak hw_perf_enable(void) { barrier(); } -int __weak -hw_perf_group_sched_in(struct perf_event *group_leader, - struct perf_cpu_context *cpuctx, - struct perf_event_context *ctx) -{ - return 0; -} - void __weak perf_event_print_debug(void) { } static DEFINE_PER_CPU(int, perf_disable_count); @@ -644,15 +636,20 @@ group_sched_in(struct perf_event *group_event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx) { - struct perf_event *event, *partial_group; + struct perf_event *event, *partial_group = NULL; + const struct pmu *pmu = group_event->pmu; + bool txn = false; int ret; if (group_event->state == PERF_EVENT_STATE_OFF) return 0; - ret = hw_perf_group_sched_in(group_event, cpuctx, ctx); - if (ret) - return ret < 0 ? ret : 0; + /* Check if group transaction availabe */ + if (pmu->start_txn) + txn = true; + + if (txn) + pmu->start_txn(pmu); if (event_sched_in(group_event, cpuctx, ctx)) return -EAGAIN; @@ -667,9 +664,19 @@ group_sched_in(struct perf_event *group_event, } } - return 0; + if (txn) { + ret = pmu->commit_txn(pmu); + if (!ret) { + pmu->cancel_txn(pmu); + + return 0; + } + } group_error: + if (txn) + pmu->cancel_txn(pmu); + /* * Groups can be scheduled in as one unit only, so undo any * partial group before returning: -- cgit v1.2.3-70-g09d2 From bbf1bb3eee86f2eef2baa14e600be454d09109ee Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 8 May 2010 16:20:53 +0200 Subject: cpu_stop: add dummy implementation for UP When !CONFIG_SMP, cpu_stop functions weren't defined at all which could lead to build failures if UP code uses cpu_stop facility. Add dummy cpu_stop implementation for UP. The waiting variants execute the work function directly with preempt disabled and stop_one_cpu_nowait() schedules a workqueue work. Makefile and ifdefs around stop_machine implementation are updated to accomodate CONFIG_SMP && !CONFIG_STOP_MACHINE case. Signed-off-by: Tejun Heo Reported-by: Ingo Molnar --- include/linux/stop_machine.h | 69 ++++++++++++++++++++++++++++++++++++++++---- kernel/Makefile | 2 +- kernel/stop_machine.c | 4 +++ 3 files changed, 68 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index 0e552e72a4c..6b524a0d02e 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -6,8 +6,6 @@ #include #include -#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) - /* * stop_cpu[s]() is simplistic per-cpu maximum priority cpu * monopolization mechanism. The caller can specify a non-sleeping @@ -18,9 +16,10 @@ * up and requests are guaranteed to be served as long as the target * cpus are online. */ - typedef int (*cpu_stop_fn_t)(void *arg); +#ifdef CONFIG_SMP + struct cpu_stop_work { struct list_head list; /* cpu_stopper->works */ cpu_stop_fn_t fn; @@ -34,12 +33,70 @@ void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); +#else /* CONFIG_SMP */ + +#include + +struct cpu_stop_work { + struct work_struct work; + cpu_stop_fn_t fn; + void *arg; +}; + +static inline int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) +{ + int ret = -ENOENT; + preempt_disable(); + if (cpu == smp_processor_id()) + ret = fn(arg); + preempt_enable(); + return ret; +} + +static void stop_one_cpu_nowait_workfn(struct work_struct *work) +{ + struct cpu_stop_work *stwork = + container_of(work, struct cpu_stop_work, work); + preempt_disable(); + stwork->fn(stwork->arg); + preempt_enable(); +} + +static inline void stop_one_cpu_nowait(unsigned int cpu, + cpu_stop_fn_t fn, void *arg, + struct cpu_stop_work *work_buf) +{ + if (cpu == smp_processor_id()) { + INIT_WORK(&work_buf->work, stop_one_cpu_nowait_workfn); + work_buf->fn = fn; + work_buf->arg = arg; + schedule_work(&work_buf->work); + } +} + +static inline int stop_cpus(const struct cpumask *cpumask, + cpu_stop_fn_t fn, void *arg) +{ + if (cpumask_test_cpu(raw_smp_processor_id(), cpumask)) + return stop_one_cpu(raw_smp_processor_id(), fn, arg); + return -ENOENT; +} + +static inline int try_stop_cpus(const struct cpumask *cpumask, + cpu_stop_fn_t fn, void *arg) +{ + return stop_cpus(cpumask, fn, arg); +} + +#endif /* CONFIG_SMP */ + /* * stop_machine "Bogolock": stop the entire machine, disable * interrupts. This is a very heavy lock, which is equivalent to * grabbing every spinlock (and more). So the "read" side to such a * lock is anything which disables preeempt. */ +#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) /** * stop_machine: freeze the machine on all CPUs and run this function @@ -67,7 +124,7 @@ int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); */ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); -#else +#else /* CONFIG_STOP_MACHINE && CONFIG_SMP */ static inline int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) @@ -79,5 +136,5 @@ static inline int stop_machine(int (*fn)(void *), void *data, return ret; } -#endif /* CONFIG_SMP */ -#endif /* _LINUX_STOP_MACHINE */ +#endif /* CONFIG_STOP_MACHINE && CONFIG_SMP */ +#endif /* _LINUX_STOP_MACHINE */ diff --git a/kernel/Makefile b/kernel/Makefile index a987aa1676b..149e18ef1ab 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -68,7 +68,7 @@ obj-$(CONFIG_USER_NS) += user_namespace.o obj-$(CONFIG_PID_NS) += pid_namespace.o obj-$(CONFIG_IKCONFIG) += configs.o obj-$(CONFIG_RESOURCE_COUNTERS) += res_counter.o -obj-$(CONFIG_STOP_MACHINE) += stop_machine.o +obj-$(CONFIG_SMP) += stop_machine.o obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o obj-$(CONFIG_AUDIT) += audit.o auditfilter.o audit_watch.o obj-$(CONFIG_AUDITSYSCALL) += auditsc.o diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 5b20141a5ec..ef51d1fcf5e 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -375,6 +375,8 @@ static int __init cpu_stop_init(void) } early_initcall(cpu_stop_init); +#ifdef CONFIG_STOP_MACHINE + /* This controls the threads on each CPU. */ enum stopmachine_state { /* Dummy starting state for thread. */ @@ -477,3 +479,5 @@ int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) return ret; } EXPORT_SYMBOL_GPL(stop_machine); + +#endif /* CONFIG_STOP_MACHINE */ -- cgit v1.2.3-70-g09d2 From 883a2a3189dae9d2912c417e47152f51cb922a3f Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 8 May 2010 06:16:11 +0200 Subject: tracing: Drop lock_acquired waittime field Drop the waittime field from the lock_acquired event, we can calculate it by substracting the lock_acquired event timestamp with the matching lock_acquire one. It is not needed and takes useless space in the traces. Signed-off-by: Frederic Weisbecker Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Hitoshi Mitake Cc: Steven Rostedt --- include/trace/events/lock.h | 11 ++++------- kernel/lockdep.c | 2 +- 2 files changed, 5 insertions(+), 8 deletions(-) (limited to 'include') diff --git a/include/trace/events/lock.h b/include/trace/events/lock.h index 5c1dcfc16c6..17ca287ae17 100644 --- a/include/trace/events/lock.h +++ b/include/trace/events/lock.h @@ -78,24 +78,21 @@ TRACE_EVENT(lock_contended, ); TRACE_EVENT(lock_acquired, - TP_PROTO(struct lockdep_map *lock, unsigned long ip, s64 waittime), + TP_PROTO(struct lockdep_map *lock, unsigned long ip), - TP_ARGS(lock, ip, waittime), + TP_ARGS(lock, ip), TP_STRUCT__entry( __string(name, lock->name) - __field(s64, wait_nsec) __field(void *, lockdep_addr) ), TP_fast_assign( __assign_str(name, lock->name); - __entry->wait_nsec = waittime; __entry->lockdep_addr = lock; ), - TP_printk("%p %s (%llu ns)", __entry->lockdep_addr, - __get_str(name), - __entry->wait_nsec) + TP_printk("%p %s", __entry->lockdep_addr, + __get_str(name)) ); #endif diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 2594e1ce41c..31e22e74236 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3380,7 +3380,7 @@ found_it: hlock->holdtime_stamp = now; } - trace_lock_acquired(lock, ip, waittime); + trace_lock_acquired(lock, ip); stats = get_lock_stats(hlock_class(hlock)); if (waittime) { -- cgit v1.2.3-70-g09d2 From 93135439459920c4d856f4ab8f068c030085c8df Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 8 May 2010 06:24:25 +0200 Subject: tracing: Drop the nested field from lock_release event Drop the nested field as we don't use it. Every nested state can be computed from a state machine on post processing already. Signed-off-by: Frederic Weisbecker Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Hitoshi Mitake Cc: Steven Rostedt --- include/trace/events/lock.h | 4 ++-- kernel/lockdep.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/trace/events/lock.h b/include/trace/events/lock.h index 17ca287ae17..fde4c385339 100644 --- a/include/trace/events/lock.h +++ b/include/trace/events/lock.h @@ -37,9 +37,9 @@ TRACE_EVENT(lock_acquire, TRACE_EVENT(lock_release, - TP_PROTO(struct lockdep_map *lock, int nested, unsigned long ip), + TP_PROTO(struct lockdep_map *lock, unsigned long ip), - TP_ARGS(lock, nested, ip), + TP_ARGS(lock, ip), TP_STRUCT__entry( __string(name, lock->name) diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 31e22e74236..e9c759f06c1 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3227,7 +3227,7 @@ void lock_release(struct lockdep_map *lock, int nested, raw_local_irq_save(flags); check_flags(flags); current->lockdep_recursion = 1; - trace_lock_release(lock, nested, ip); + trace_lock_release(lock, ip); __lock_release(lock, nested, ip); current->lockdep_recursion = 0; raw_local_irq_restore(flags); -- cgit v1.2.3-70-g09d2 From 2c193c736803ceb547daec725e5c5d992d039f20 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 8 May 2010 06:36:02 +0200 Subject: tracing: Factorize lock events in a lock class lock_acquired, lock_contended and lock_release now share the same prototype and format. Let's factorize them into a lock event class. Signed-off-by: Frederic Weisbecker Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Hitoshi Mitake Cc: Steven Rostedt --- include/trace/events/lock.h | 48 ++++++++++++++------------------------------- 1 file changed, 15 insertions(+), 33 deletions(-) (limited to 'include') diff --git a/include/trace/events/lock.h b/include/trace/events/lock.h index fde4c385339..2821b86de63 100644 --- a/include/trace/events/lock.h +++ b/include/trace/events/lock.h @@ -35,15 +35,15 @@ TRACE_EVENT(lock_acquire, __get_str(name)) ); -TRACE_EVENT(lock_release, +DECLARE_EVENT_CLASS(lock, TP_PROTO(struct lockdep_map *lock, unsigned long ip), TP_ARGS(lock, ip), TP_STRUCT__entry( - __string(name, lock->name) - __field(void *, lockdep_addr) + __string( name, lock->name ) + __field( void *, lockdep_addr ) ), TP_fast_assign( @@ -51,48 +51,30 @@ TRACE_EVENT(lock_release, __entry->lockdep_addr = lock; ), - TP_printk("%p %s", - __entry->lockdep_addr, __get_str(name)) + TP_printk("%p %s", __entry->lockdep_addr, __get_str(name)) ); -#ifdef CONFIG_LOCK_STAT - -TRACE_EVENT(lock_contended, +DEFINE_EVENT(lock, lock_release, TP_PROTO(struct lockdep_map *lock, unsigned long ip), - TP_ARGS(lock, ip), - - TP_STRUCT__entry( - __string(name, lock->name) - __field(void *, lockdep_addr) - ), + TP_ARGS(lock, ip) +); - TP_fast_assign( - __assign_str(name, lock->name); - __entry->lockdep_addr = lock; - ), +#ifdef CONFIG_LOCK_STAT - TP_printk("%p %s", - __entry->lockdep_addr, __get_str(name)) -); +DEFINE_EVENT(lock, lock_contended, -TRACE_EVENT(lock_acquired, TP_PROTO(struct lockdep_map *lock, unsigned long ip), - TP_ARGS(lock, ip), + TP_ARGS(lock, ip) +); - TP_STRUCT__entry( - __string(name, lock->name) - __field(void *, lockdep_addr) - ), +DEFINE_EVENT(lock, lock_acquired, - TP_fast_assign( - __assign_str(name, lock->name); - __entry->lockdep_addr = lock; - ), - TP_printk("%p %s", __entry->lockdep_addr, - __get_str(name)) + TP_PROTO(struct lockdep_map *lock, unsigned long ip), + + TP_ARGS(lock, ip) ); #endif -- cgit v1.2.3-70-g09d2 From e0e37c200f1357db0dd986edb359c41c57d24f6e Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sun, 9 May 2010 08:24:39 -0700 Subject: sched: Eliminate the ts->idle_lastupdate field Now that the only user of ts->idle_lastupdate is update_ts_time_stats(), the entire field can be eliminated. In update_ts_time_stats(), idle_lastupdate is first set to "now", and a few lines later, the only user is an if() statement that assigns a variable either to "now" or to ts->idle_lastupdate, which has the value of "now" at that point. Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Reviewed-by: Rik van Riel Acked-by: Peter Zijlstra Cc: davej@redhat.com LKML-Reference: <20100509082439.2fab0b4f@infradead.org> Signed-off-by: Ingo Molnar --- include/linux/tick.h | 1 - kernel/time/tick-sched.c | 5 +---- 2 files changed, 1 insertion(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/tick.h b/include/linux/tick.h index d2ae79e21be..0343eed4061 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -60,7 +60,6 @@ struct tick_sched { ktime_t idle_waketime; ktime_t idle_exittime; ktime_t idle_sleeptime; - ktime_t idle_lastupdate; ktime_t sleep_length; unsigned long last_jiffies; unsigned long next_jiffies; diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index e86e1c6674d..50953f4c42b 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -158,16 +158,13 @@ update_ts_time_stats(struct tick_sched *ts, ktime_t now, u64 *last_update_time) { ktime_t delta; - ts->idle_lastupdate = now; if (ts->idle_active) { delta = ktime_sub(now, ts->idle_entrytime); ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); ts->idle_entrytime = now; } - if (ts->idle_active && last_update_time) - *last_update_time = ktime_to_us(ts->idle_lastupdate); - else + if (last_update_time) *last_update_time = ktime_to_us(now); } -- cgit v1.2.3-70-g09d2 From 0224cf4c5ee0d7faec83956b8e21f7d89e3df3bd Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sun, 9 May 2010 08:25:23 -0700 Subject: sched: Intoduce get_cpu_iowait_time_us() For the ondemand cpufreq governor, it is desired that the iowait time is microaccounted in a similar way as idle time is. This patch introduces the infrastructure to account and expose this information via the get_cpu_iowait_time_us() function. [akpm@linux-foundation.org: fix CONFIG_NO_HZ=n build] Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Reviewed-by: Rik van Riel Acked-by: Peter Zijlstra Cc: davej@redhat.com LKML-Reference: <20100509082523.284feab6@infradead.org> Signed-off-by: Ingo Molnar --- include/linux/tick.h | 4 ++++ kernel/time/tick-sched.c | 28 ++++++++++++++++++++++++++++ kernel/time/timer_list.c | 1 + 3 files changed, 33 insertions(+) (limited to 'include') diff --git a/include/linux/tick.h b/include/linux/tick.h index 0343eed4061..b232ccc0ee2 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -42,6 +42,7 @@ enum tick_nohz_mode { * @idle_waketime: Time when the idle was interrupted * @idle_exittime: Time when the idle state was left * @idle_sleeptime: Sum of the time slept in idle with sched tick stopped + * @iowait_sleeptime: Sum of the time slept in idle with sched tick stopped, with IO outstanding * @sleep_length: Duration of the current idle sleep * @do_timer_lst: CPU was the last one doing do_timer before going idle */ @@ -60,6 +61,7 @@ struct tick_sched { ktime_t idle_waketime; ktime_t idle_exittime; ktime_t idle_sleeptime; + ktime_t iowait_sleeptime; ktime_t sleep_length; unsigned long last_jiffies; unsigned long next_jiffies; @@ -123,6 +125,7 @@ extern void tick_nohz_stop_sched_tick(int inidle); extern void tick_nohz_restart_sched_tick(void); extern ktime_t tick_nohz_get_sleep_length(void); extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); +extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); # else static inline void tick_nohz_stop_sched_tick(int inidle) { } static inline void tick_nohz_restart_sched_tick(void) { } @@ -133,6 +136,7 @@ static inline ktime_t tick_nohz_get_sleep_length(void) return len; } static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; } +static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; } # endif /* !NO_HZ */ #endif diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 50953f4c42b..1d7b9bc1c03 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -161,6 +161,8 @@ update_ts_time_stats(struct tick_sched *ts, ktime_t now, u64 *last_update_time) if (ts->idle_active) { delta = ktime_sub(now, ts->idle_entrytime); ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); + if (nr_iowait_cpu() > 0) + ts->iowait_sleeptime = ktime_add(ts->iowait_sleeptime, delta); ts->idle_entrytime = now; } @@ -220,6 +222,32 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time) } EXPORT_SYMBOL_GPL(get_cpu_idle_time_us); +/* + * get_cpu_iowait_time_us - get the total iowait time of a cpu + * @cpu: CPU number to query + * @last_update_time: variable to store update time in + * + * Return the cummulative iowait time (since boot) for a given + * CPU, in microseconds. + * + * This time is measured via accounting rather than sampling, + * and is as accurate as ktime_get() is. + * + * This function returns -1 if NOHZ is not enabled. + */ +u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time) +{ + struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + + if (!tick_nohz_enabled) + return -1; + + update_ts_time_stats(ts, ktime_get(), last_update_time); + + return ktime_to_us(ts->iowait_sleeptime); +} +EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us); + /** * tick_nohz_stop_sched_tick - stop the idle tick from the idle task * diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 1a4a7dd7877..ab8f5e33fa9 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -176,6 +176,7 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now) P_ns(idle_waketime); P_ns(idle_exittime); P_ns(idle_sleeptime); + P_ns(iowait_sleeptime); P(last_jiffies); P(next_jiffies); P_ns(idle_expires); -- cgit v1.2.3-70-g09d2 From 2b3fc35f6919344e3cf722dde8308f47235c0b70 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Tue, 20 Apr 2010 16:23:07 +0800 Subject: rcu: optionally leave lockdep enabled after RCU lockdep splat There is no need to disable lockdep after an RCU lockdep splat, so remove the debug_lockdeps_off() from lockdep_rcu_dereference(). To avoid repeated lockdep splats, use a static variable in the inlined rcu_dereference_check() and rcu_dereference_protected() macros so that a given instance splats only once, but so that multiple instances can be detected per boot. This is controlled by a new config variable CONFIG_PROVE_RCU_REPEATEDLY, which is disabled by default. This provides the normal lockdep behavior by default, but permits people who want to find multiple RCU-lockdep splats per boot to easily do so. Requested-by: Eric Paris Signed-off-by: Lai Jiangshan Tested-by: Eric Paris Signed-off-by: Paul E. McKenney --- include/linux/rcupdate.h | 15 +++++++++++---- kernel/lockdep.c | 3 +++ lib/Kconfig.debug | 12 ++++++++++++ 3 files changed, 26 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index db266bbed23..4dca2752cfd 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -192,6 +192,15 @@ static inline int rcu_read_lock_sched_held(void) extern int rcu_my_thread_group_empty(void); +#define __do_rcu_dereference_check(c) \ + do { \ + static bool __warned; \ + if (debug_lockdep_rcu_enabled() && !__warned && !(c)) { \ + __warned = true; \ + lockdep_rcu_dereference(__FILE__, __LINE__); \ + } \ + } while (0) + /** * rcu_dereference_check - rcu_dereference with debug checking * @p: The pointer to read, prior to dereferencing @@ -221,8 +230,7 @@ extern int rcu_my_thread_group_empty(void); */ #define rcu_dereference_check(p, c) \ ({ \ - if (debug_lockdep_rcu_enabled() && !(c)) \ - lockdep_rcu_dereference(__FILE__, __LINE__); \ + __do_rcu_dereference_check(c); \ rcu_dereference_raw(p); \ }) @@ -239,8 +247,7 @@ extern int rcu_my_thread_group_empty(void); */ #define rcu_dereference_protected(p, c) \ ({ \ - if (debug_lockdep_rcu_enabled() && !(c)) \ - lockdep_rcu_dereference(__FILE__, __LINE__); \ + __do_rcu_dereference_check(c); \ (p); \ }) diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 2594e1ce41c..3a756ba8d5d 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3801,8 +3801,11 @@ void lockdep_rcu_dereference(const char *file, const int line) { struct task_struct *curr = current; +#ifndef CONFIG_PROVE_RCU_REPEATEDLY if (!debug_locks_off()) return; +#endif /* #ifdef CONFIG_PROVE_RCU_REPEATEDLY */ + /* Note: the following can be executed concurrently, so be careful. */ printk("\n===================================================\n"); printk( "[ INFO: suspicious rcu_dereference_check() usage. ]\n"); printk( "---------------------------------------------------\n"); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 935248bdbc4..94090b4bb7d 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -512,6 +512,18 @@ config PROVE_RCU Say N if you are unsure. +config PROVE_RCU_REPEATEDLY + bool "RCU debugging: don't disable PROVE_RCU on first splat" + depends on PROVE_RCU + default n + help + By itself, PROVE_RCU will disable checking upon issuing the + first warning (or "splat"). This feature prevents such + disabling, allowing multiple RCU-lockdep warnings to be printed + on a single reboot. + + Say N if you are unsure. + config LOCKDEP bool depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT -- cgit v1.2.3-70-g09d2 From d20200b591f59847ab6a5c23507084a7d29e23c5 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 30 Mar 2010 10:52:21 -0700 Subject: rcu: Fix bogus CONFIG_PROVE_LOCKING in comments to reflect reality. It is CONFIG_DEBUG_LOCK_ALLOC rather than CONFIG_PROVE_LOCKING, so fix it. Signed-off-by: Paul E. McKenney --- include/linux/rcupdate.h | 15 ++++++++------- include/linux/srcu.h | 4 ++-- 2 files changed, 10 insertions(+), 9 deletions(-) (limited to 'include') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 4dca2752cfd..a150af0e5cd 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -106,8 +106,8 @@ extern int debug_lockdep_rcu_enabled(void); /** * rcu_read_lock_held - might we be in RCU read-side critical section? * - * If CONFIG_PROVE_LOCKING is selected and enabled, returns nonzero iff in - * an RCU read-side critical section. In absence of CONFIG_PROVE_LOCKING, + * If CONFIG_DEBUG_LOCK_ALLOC is selected, returns nonzero iff in an RCU + * read-side critical section. In absence of CONFIG_DEBUG_LOCK_ALLOC, * this assumes we are in an RCU read-side critical section unless it can * prove otherwise. * @@ -129,11 +129,12 @@ extern int rcu_read_lock_bh_held(void); /** * rcu_read_lock_sched_held - might we be in RCU-sched read-side critical section? * - * If CONFIG_PROVE_LOCKING is selected and enabled, returns nonzero iff in an - * RCU-sched read-side critical section. In absence of CONFIG_PROVE_LOCKING, - * this assumes we are in an RCU-sched read-side critical section unless it - * can prove otherwise. Note that disabling of preemption (including - * disabling irqs) counts as an RCU-sched read-side critical section. + * If CONFIG_DEBUG_LOCK_ALLOC is selected, returns nonzero iff in an + * RCU-sched read-side critical section. In absence of + * CONFIG_DEBUG_LOCK_ALLOC, this assumes we are in an RCU-sched read-side + * critical section unless it can prove otherwise. Note that disabling + * of preemption (including disabling irqs) counts as an RCU-sched + * read-side critical section. * * Check rcu_scheduler_active to prevent false positives during boot. */ diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 4d5ecb222af..9c01f102242 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -84,8 +84,8 @@ long srcu_batches_completed(struct srcu_struct *sp); /** * srcu_read_lock_held - might we be in SRCU read-side critical section? * - * If CONFIG_PROVE_LOCKING is selected and enabled, returns nonzero iff in - * an SRCU read-side critical section. In absence of CONFIG_PROVE_LOCKING, + * If CONFIG_DEBUG_LOCK_ALLOC is selected, returns nonzero iff in an SRCU + * read-side critical section. In absence of CONFIG_DEBUG_LOCK_ALLOC, * this assumes we are in an SRCU read-side critical section unless it can * prove otherwise. */ -- cgit v1.2.3-70-g09d2 From 32c141a0a1dfa29e0a07d78bec0c0919fc4b9f88 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 30 Mar 2010 10:59:28 -0700 Subject: rcu: fix now-bogus rcu_scheduler_active comments. The rcu_scheduler_active check has been wrapped into the new debug_lockdep_rcu_enabled() function, so update the comments to reflect this new reality. Signed-off-by: Paul E. McKenney --- include/linux/rcupdate.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index a150af0e5cd..02537a72aaa 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -111,7 +111,8 @@ extern int debug_lockdep_rcu_enabled(void); * this assumes we are in an RCU read-side critical section unless it can * prove otherwise. * - * Check rcu_scheduler_active to prevent false positives during boot. + * Check debug_lockdep_rcu_enabled() to prevent false positives during boot + * and while lockdep is disabled. */ static inline int rcu_read_lock_held(void) { @@ -136,7 +137,8 @@ extern int rcu_read_lock_bh_held(void); * of preemption (including disabling irqs) counts as an RCU-sched * read-side critical section. * - * Check rcu_scheduler_active to prevent false positives during boot. + * Check debug_lockdep_rcu_enabled() to prevent false positives during boot + * and while lockdep is disabled. */ #ifdef CONFIG_PREEMPT static inline int rcu_read_lock_sched_held(void) -- cgit v1.2.3-70-g09d2 From da848c47bc6e873a54a445ea1960423a495b6b32 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 30 Mar 2010 15:46:01 -0700 Subject: rcu: shrink rcutiny by making synchronize_rcu_bh() be inline Because synchronize_rcu_bh() is identical to synchronize_sched(), make the former a static inline invoking the latter, saving the overhead of an EXPORT_SYMBOL_GPL() and the duplicate code. Signed-off-by: Paul E. McKenney --- include/linux/rcupdate.h | 2 -- include/linux/rcutiny.h | 12 +++++++++++- include/linux/rcutree.h | 2 ++ kernel/rcutiny.c | 9 ++------- 4 files changed, 15 insertions(+), 10 deletions(-) (limited to 'include') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 02537a72aaa..d8fb2abcf30 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -56,8 +56,6 @@ struct rcu_head { }; /* Exported common interfaces */ -extern void synchronize_rcu_bh(void); -extern void synchronize_sched(void); extern void rcu_barrier(void); extern void rcu_barrier_bh(void); extern void rcu_barrier_sched(void); diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index a5195875480..bbeb55b7709 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -74,7 +74,17 @@ static inline void rcu_sched_force_quiescent_state(void) { } -#define synchronize_rcu synchronize_sched +extern void synchronize_sched(void); + +static inline void synchronize_rcu(void) +{ + synchronize_sched(); +} + +static inline void synchronize_rcu_bh(void) +{ + synchronize_sched(); +} static inline void synchronize_rcu_expedited(void) { diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 42cc3a04779..7484fe66a3a 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -86,6 +86,8 @@ static inline void __rcu_read_unlock_bh(void) extern void call_rcu_sched(struct rcu_head *head, void (*func)(struct rcu_head *rcu)); +extern void synchronize_rcu_bh(void); +extern void synchronize_sched(void); extern void synchronize_rcu_expedited(void); static inline void synchronize_rcu_bh_expedited(void) diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c index 9f6d9ff2572..272c6d21a75 100644 --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -187,7 +187,8 @@ static void rcu_process_callbacks(struct softirq_action *unused) * * Cool, huh? (Due to Josh Triplett.) * - * But we want to make this a static inline later. + * But we want to make this a static inline later. The cond_resched() + * currently makes this problematic. */ void synchronize_sched(void) { @@ -195,12 +196,6 @@ void synchronize_sched(void) } EXPORT_SYMBOL_GPL(synchronize_sched); -void synchronize_rcu_bh(void) -{ - synchronize_sched(); -} -EXPORT_SYMBOL_GPL(synchronize_rcu_bh); - /* * Helper function for call_rcu() and call_rcu_bh(). */ -- cgit v1.2.3-70-g09d2 From 25502a6c13745f4650cc59322bd198194f55e796 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 1 Apr 2010 17:37:01 -0700 Subject: rcu: refactor RCU's context-switch handling The addition of preemptible RCU to treercu resulted in a bit of confusion and inefficiency surrounding the handling of context switches for RCU-sched and for RCU-preempt. For RCU-sched, a context switch is a quiescent state, pure and simple, just like it always has been. For RCU-preempt, a context switch is in no way a quiescent state, but special handling is required when a task blocks in an RCU read-side critical section. However, the callout from the scheduler and the outer loop in ksoftirqd still calls something named rcu_sched_qs(), whose name is no longer accurate. Furthermore, when rcu_check_callbacks() notes an RCU-sched quiescent state, it ends up unnecessarily (though harmlessly, aside from the performance hit) enqueuing the current task if it happens to be running in an RCU-preempt read-side critical section. This not only increases the maximum latency of scheduler_tick(), it also needlessly increases the overhead of the next outermost rcu_read_unlock() invocation. This patch addresses this situation by separating the notion of RCU's context-switch handling from that of RCU-sched's quiescent states. The context-switch handling is covered by rcu_note_context_switch() in general and by rcu_preempt_note_context_switch() for preemptible RCU. This permits rcu_sched_qs() to handle quiescent states and only quiescent states. It also reduces the maximum latency of scheduler_tick(), though probably by much less than a microsecond. Finally, it means that tasks within preemptible-RCU read-side critical sections avoid incurring the overhead of queuing unless there really is a context switch. Suggested-by: Lai Jiangshan Acked-by: Lai Jiangshan Signed-off-by: Paul E. McKenney Cc: Ingo Molnar Cc: Peter Zijlstra --- include/linux/rcutiny.h | 4 ++++ include/linux/rcutree.h | 1 + kernel/rcutree.c | 17 ++++++++++++----- kernel/rcutree_plugin.h | 11 +++++++---- kernel/sched.c | 2 +- kernel/softirq.c | 2 +- 6 files changed, 26 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index bbeb55b7709..ff22b97fb97 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -29,6 +29,10 @@ void rcu_sched_qs(int cpu); void rcu_bh_qs(int cpu); +static inline void rcu_note_context_switch(int cpu) +{ + rcu_sched_qs(cpu); +} #define __rcu_read_lock() preempt_disable() #define __rcu_read_unlock() preempt_enable() diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 7484fe66a3a..b9f74606f32 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -34,6 +34,7 @@ struct notifier_block; extern void rcu_sched_qs(int cpu); extern void rcu_bh_qs(int cpu); +extern void rcu_note_context_switch(int cpu); extern int rcu_needs_cpu(int cpu); extern int rcu_expedited_torture_stats(char *page); diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 86bb9499aae..e33631354b6 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -97,25 +97,32 @@ static int rcu_gp_in_progress(struct rcu_state *rsp) */ void rcu_sched_qs(int cpu) { - struct rcu_data *rdp; + struct rcu_data *rdp = &per_cpu(rcu_sched_data, cpu); - rdp = &per_cpu(rcu_sched_data, cpu); rdp->passed_quiesc_completed = rdp->gpnum - 1; barrier(); rdp->passed_quiesc = 1; - rcu_preempt_note_context_switch(cpu); } void rcu_bh_qs(int cpu) { - struct rcu_data *rdp; + struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu); - rdp = &per_cpu(rcu_bh_data, cpu); rdp->passed_quiesc_completed = rdp->gpnum - 1; barrier(); rdp->passed_quiesc = 1; } +/* + * Note a context switch. This is a quiescent state for RCU-sched, + * and requires special handling for preemptible RCU. + */ +void rcu_note_context_switch(int cpu) +{ + rcu_sched_qs(cpu); + rcu_preempt_note_context_switch(cpu); +} + #ifdef CONFIG_NO_HZ DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = { .dynticks_nesting = 1, diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 687c4e90722..f9bc83a047d 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -75,13 +75,19 @@ EXPORT_SYMBOL_GPL(rcu_force_quiescent_state); * that this just means that the task currently running on the CPU is * not in a quiescent state. There might be any number of tasks blocked * while in an RCU read-side critical section. + * + * Unlike the other rcu_*_qs() functions, callers to this function + * must disable irqs in order to protect the assignment to + * ->rcu_read_unlock_special. */ static void rcu_preempt_qs(int cpu) { struct rcu_data *rdp = &per_cpu(rcu_preempt_data, cpu); + rdp->passed_quiesc_completed = rdp->gpnum - 1; barrier(); rdp->passed_quiesc = 1; + current->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; } /* @@ -144,9 +150,8 @@ static void rcu_preempt_note_context_switch(int cpu) * grace period, then the fact that the task has been enqueued * means that we continue to block the current grace period. */ - rcu_preempt_qs(cpu); local_irq_save(flags); - t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; + rcu_preempt_qs(cpu); local_irq_restore(flags); } @@ -236,7 +241,6 @@ static void rcu_read_unlock_special(struct task_struct *t) */ special = t->rcu_read_unlock_special; if (special & RCU_READ_UNLOCK_NEED_QS) { - t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; rcu_preempt_qs(smp_processor_id()); } @@ -473,7 +477,6 @@ static void rcu_preempt_check_callbacks(int cpu) struct task_struct *t = current; if (t->rcu_read_lock_nesting == 0) { - t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; rcu_preempt_qs(cpu); return; } diff --git a/kernel/sched.c b/kernel/sched.c index 3c2a54f70ff..d8a213ccdc3 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3706,7 +3706,7 @@ need_resched: preempt_disable(); cpu = smp_processor_id(); rq = cpu_rq(cpu); - rcu_sched_qs(cpu); + rcu_note_context_switch(cpu); prev = rq->curr; switch_count = &prev->nivcsw; diff --git a/kernel/softirq.c b/kernel/softirq.c index 7c1a67ef027..0db913a5c60 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -716,7 +716,7 @@ static int run_ksoftirqd(void * __bind_cpu) preempt_enable_no_resched(); cond_resched(); preempt_disable(); - rcu_sched_qs((long)__bind_cpu); + rcu_note_context_switch((long)__bind_cpu); } preempt_enable(); set_current_state(TASK_INTERRUPTIBLE); -- cgit v1.2.3-70-g09d2 From bbad937983147c017c25406860287cb94da9af7c Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 2 Apr 2010 16:17:17 -0700 Subject: rcu: slim down rcutiny by removing rcu_scheduler_active and friends TINY_RCU does not need rcu_scheduler_active unless CONFIG_DEBUG_LOCK_ALLOC. So conditionally compile rcu_scheduler_active in order to slim down rcutiny a bit more. Also gets rid of an EXPORT_SYMBOL_GPL, which is responsible for most of the slimming. Signed-off-by: Paul E. McKenney --- include/linux/rcupdate.h | 4 +--- include/linux/rcutiny.h | 13 +++++++++++++ include/linux/rcutree.h | 3 +++ kernel/rcupdate.c | 19 ------------------- kernel/rcutiny.c | 7 +++++++ kernel/rcutiny_plugin.h | 39 +++++++++++++++++++++++++++++++++++++++ kernel/rcutree.c | 19 +++++++++++++++++++ 7 files changed, 82 insertions(+), 22 deletions(-) create mode 100644 kernel/rcutiny_plugin.h (limited to 'include') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index d8fb2abcf30..23be3a70251 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -64,8 +64,6 @@ extern int sched_expedited_torture_stats(char *page); /* Internal to kernel */ extern void rcu_init(void); -extern int rcu_scheduler_active; -extern void rcu_scheduler_starting(void); #if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU) #include @@ -178,7 +176,7 @@ static inline int rcu_read_lock_bh_held(void) #ifdef CONFIG_PREEMPT static inline int rcu_read_lock_sched_held(void) { - return !rcu_scheduler_active || preempt_count() != 0 || irqs_disabled(); + return preempt_count() != 0 || irqs_disabled(); } #else /* #ifdef CONFIG_PREEMPT */ static inline int rcu_read_lock_sched_held(void) diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index ff22b97fb97..14e5a76b2c0 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -128,4 +128,17 @@ static inline int rcu_preempt_depth(void) return 0; } +#ifdef CONFIG_DEBUG_LOCK_ALLOC + +extern int rcu_scheduler_active __read_mostly; +extern void rcu_scheduler_starting(void); + +#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ + +static inline void rcu_scheduler_starting(void) +{ +} + +#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ + #endif /* __LINUX_RCUTINY_H */ diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index b9f74606f32..48282055e83 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -123,4 +123,7 @@ static inline int rcu_blocking_is_gp(void) return num_online_cpus() == 1; } +extern void rcu_scheduler_starting(void); +extern int rcu_scheduler_active __read_mostly; + #endif /* __LINUX_RCUTREE_H */ diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index 49d808e833b..72a8dc9567f 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -44,7 +44,6 @@ #include #include #include -#include #include #ifdef CONFIG_DEBUG_LOCK_ALLOC @@ -64,9 +63,6 @@ struct lockdep_map rcu_sched_lock_map = EXPORT_SYMBOL_GPL(rcu_sched_lock_map); #endif -int rcu_scheduler_active __read_mostly; -EXPORT_SYMBOL_GPL(rcu_scheduler_active); - #ifdef CONFIG_DEBUG_LOCK_ALLOC int debug_lockdep_rcu_enabled(void) @@ -96,21 +92,6 @@ EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held); #endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ -/* - * This function is invoked towards the end of the scheduler's initialization - * process. Before this is called, the idle task might contain - * RCU read-side critical sections (during which time, this idle - * task is booting the system). After this function is called, the - * idle tasks are prohibited from containing RCU read-side critical - * sections. - */ -void rcu_scheduler_starting(void) -{ - WARN_ON(num_online_cpus() != 1); - WARN_ON(nr_context_switches() > 0); - rcu_scheduler_active = 1; -} - /* * Awaken the corresponding synchronize_rcu() instance now that a * grace period has elapsed. diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c index d9f8a623c9f..b1804ff83d5 100644 --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -54,6 +54,11 @@ static struct rcu_ctrlblk rcu_bh_ctrlblk = { .curtail = &rcu_bh_ctrlblk.rcucblist, }; +#ifdef CONFIG_DEBUG_LOCK_ALLOC +int rcu_scheduler_active __read_mostly; +EXPORT_SYMBOL_GPL(rcu_scheduler_active); +#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ + #ifdef CONFIG_NO_HZ static long rcu_dynticks_nesting = 1; @@ -276,3 +281,5 @@ void __init rcu_init(void) { open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); } + +#include "rcutiny_plugin.h" diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h new file mode 100644 index 00000000000..d223a92bc74 --- /dev/null +++ b/kernel/rcutiny_plugin.h @@ -0,0 +1,39 @@ +/* + * Read-Copy Update mechanism for mutual exclusion (tree-based version) + * Internal non-public definitions that provide either classic + * or preemptable semantics. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright IBM Corporation, 2009 + * + * Author: Paul E. McKenney + */ + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + +#include + +/* + * During boot, we forgive RCU lockdep issues. After this function is + * invoked, we start taking RCU lockdep issues seriously. + */ +void rcu_scheduler_starting(void) +{ + WARN_ON(nr_context_switches() > 0); + rcu_scheduler_active = 1; +} + +#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ diff --git a/kernel/rcutree.c b/kernel/rcutree.c index e33631354b6..3623f8e1022 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -46,6 +46,7 @@ #include #include #include +#include #include "rcutree.h" @@ -80,6 +81,9 @@ DEFINE_PER_CPU(struct rcu_data, rcu_sched_data); struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state); DEFINE_PER_CPU(struct rcu_data, rcu_bh_data); +int rcu_scheduler_active __read_mostly; +EXPORT_SYMBOL_GPL(rcu_scheduler_active); + /* * Return true if an RCU grace period is in progress. The ACCESS_ONCE()s * permit this function to be invoked without holding the root rcu_node @@ -1783,6 +1787,21 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, return NOTIFY_OK; } +/* + * This function is invoked towards the end of the scheduler's initialization + * process. Before this is called, the idle task might contain + * RCU read-side critical sections (during which time, this idle + * task is booting the system). After this function is called, the + * idle tasks are prohibited from containing RCU read-side critical + * sections. This function also enables RCU lockdep checking. + */ +void rcu_scheduler_starting(void) +{ + WARN_ON(num_online_cpus() != 1); + WARN_ON(nr_context_switches() > 0); + rcu_scheduler_active = 1; +} + /* * Compute the per-level fanout, either using the exact fanout specified * or balancing the tree, depending on CONFIG_RCU_FANOUT_EXACT. -- cgit v1.2.3-70-g09d2 From d14aada8e20bdf81ffd43f433b123972cf575b32 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 19 Apr 2010 22:24:22 -0700 Subject: rcu: make SRCU usable in modules Add a #include for mutex.h to allow SRCU to be more easily used in kernel modules. Signed-off-by: Lai Jiangshan Signed-off-by: Paul E. McKenney --- include/linux/srcu.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 9c01f102242..4d5d2f546db 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -27,6 +27,8 @@ #ifndef _LINUX_SRCU_H #define _LINUX_SRCU_H +#include + struct srcu_struct_array { int c[2]; }; -- cgit v1.2.3-70-g09d2 From a5d8e467f83f6672104f276223a88e3b50cbd375 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Sat, 17 Apr 2010 08:48:38 -0400 Subject: Debugobjects transition check Implement a basic state machine checker in the debugobjects. This state machine checker detects races and inconsistencies within the "active" life of a debugobject. The checker only keeps track of the current state; all the state machine logic is kept at the object instance level. The checker works by adding a supplementary "unsigned int astate" field to the debug_obj structure. It keeps track of the current "active state" of the object. The only constraints that are imposed on the states by the debugobjects system is that: - activation of an object sets the current active state to 0, - deactivation of an object expects the current active state to be 0. For the rest of the states, the state mapping is determined by the specific object instance. Therefore, the logic keeping track of the state machine is within the specialized instance, without any need to know about it at the debugobject level. The current object active state is changed by calling: debug_object_active_state(addr, descr, expect, next) where "expect" is the expected state and "next" is the next state to move to if the expected state is found. A warning is generated if the expected is not found. Signed-off-by: Mathieu Desnoyers Reviewed-by: Thomas Gleixner Acked-by: David S. Miller CC: "Paul E. McKenney" CC: akpm@linux-foundation.org CC: mingo@elte.hu CC: laijs@cn.fujitsu.com CC: dipankar@in.ibm.com CC: josh@joshtriplett.org CC: dvhltc@us.ibm.com CC: niv@us.ibm.com CC: peterz@infradead.org CC: rostedt@goodmis.org CC: Valdis.Kletnieks@vt.edu CC: dhowells@redhat.com CC: eric.dumazet@gmail.com CC: Alexey Dobriyan Signed-off-by: Paul E. McKenney --- include/linux/debugobjects.h | 11 +++++++++ lib/debugobjects.c | 59 +++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 67 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/debugobjects.h b/include/linux/debugobjects.h index 8c243aaa86a..597692f1fc8 100644 --- a/include/linux/debugobjects.h +++ b/include/linux/debugobjects.h @@ -20,12 +20,14 @@ struct debug_obj_descr; * struct debug_obj - representaion of an tracked object * @node: hlist node to link the object into the tracker list * @state: tracked object state + * @astate: current active state * @object: pointer to the real object * @descr: pointer to an object type specific debug description structure */ struct debug_obj { struct hlist_node node; enum debug_obj_state state; + unsigned int astate; void *object; struct debug_obj_descr *descr; }; @@ -60,6 +62,15 @@ extern void debug_object_deactivate(void *addr, struct debug_obj_descr *descr); extern void debug_object_destroy (void *addr, struct debug_obj_descr *descr); extern void debug_object_free (void *addr, struct debug_obj_descr *descr); +/* + * Active state: + * - Set at 0 upon initialization. + * - Must return to 0 before deactivation. + */ +extern void +debug_object_active_state(void *addr, struct debug_obj_descr *descr, + unsigned int expect, unsigned int next); + extern void debug_objects_early_init(void); extern void debug_objects_mem_init(void); #else diff --git a/lib/debugobjects.c b/lib/debugobjects.c index b862b30369f..076464fd207 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -141,6 +141,7 @@ alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr) obj->object = addr; obj->descr = descr; obj->state = ODEBUG_STATE_NONE; + obj->astate = 0; hlist_del(&obj->node); hlist_add_head(&obj->node, &b->list); @@ -252,8 +253,10 @@ static void debug_print_object(struct debug_obj *obj, char *msg) if (limit < 5 && obj->descr != descr_test) { limit++; - WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg, - obj_states[obj->state], obj->descr->name); + WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) " + "object type: %s\n", + msg, obj_states[obj->state], obj->astate, + obj->descr->name); } debug_objects_warnings++; } @@ -447,7 +450,10 @@ void debug_object_deactivate(void *addr, struct debug_obj_descr *descr) case ODEBUG_STATE_INIT: case ODEBUG_STATE_INACTIVE: case ODEBUG_STATE_ACTIVE: - obj->state = ODEBUG_STATE_INACTIVE; + if (!obj->astate) + obj->state = ODEBUG_STATE_INACTIVE; + else + debug_print_object(obj, "deactivate"); break; case ODEBUG_STATE_DESTROYED: @@ -553,6 +559,53 @@ out_unlock: raw_spin_unlock_irqrestore(&db->lock, flags); } +/** + * debug_object_active_state - debug checks object usage state machine + * @addr: address of the object + * @descr: pointer to an object specific debug description structure + * @expect: expected state + * @next: state to move to if expected state is found + */ +void +debug_object_active_state(void *addr, struct debug_obj_descr *descr, + unsigned int expect, unsigned int next) +{ + struct debug_bucket *db; + struct debug_obj *obj; + unsigned long flags; + + if (!debug_objects_enabled) + return; + + db = get_bucket((unsigned long) addr); + + raw_spin_lock_irqsave(&db->lock, flags); + + obj = lookup_object(addr, db); + if (obj) { + switch (obj->state) { + case ODEBUG_STATE_ACTIVE: + if (obj->astate == expect) + obj->astate = next; + else + debug_print_object(obj, "active_state"); + break; + + default: + debug_print_object(obj, "active_state"); + break; + } + } else { + struct debug_obj o = { .object = addr, + .state = ODEBUG_STATE_NOTAVAILABLE, + .descr = descr }; + + debug_print_object(&o, "active_state"); + } + + raw_spin_unlock_irqrestore(&db->lock, flags); +} + #ifdef CONFIG_DEBUG_OBJECTS_FREE static void __debug_check_no_obj_freed(const void *address, unsigned long size) { -- cgit v1.2.3-70-g09d2 From 4376030a54860dedab9d848dfa7cc700a6025c0b Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Sat, 17 Apr 2010 08:48:39 -0400 Subject: rcu head introduce rcu head init on stack PEM: o Would it be possible to make this bisectable as follows? a. Insert a new patch after current patch 4/6 that defines destroy_rcu_head_on_stack(), init_rcu_head_on_stack(), and init_rcu_head() with their !CONFIG_DEBUG_OBJECTS_RCU_HEAD definitions. This patch performs this transition. Signed-off-by: Mathieu Desnoyers CC: "Paul E. McKenney" CC: David S. Miller CC: akpm@linux-foundation.org CC: mingo@elte.hu CC: laijs@cn.fujitsu.com CC: dipankar@in.ibm.com CC: josh@joshtriplett.org CC: dvhltc@us.ibm.com CC: niv@us.ibm.com CC: tglx@linutronix.de CC: peterz@infradead.org CC: rostedt@goodmis.org CC: Valdis.Kletnieks@vt.edu CC: dhowells@redhat.com CC: eric.dumazet@gmail.com CC: Alexey Dobriyan Signed-off-by: Paul E. McKenney --- include/linux/rcupdate.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 23be3a70251..b653b4aaa8a 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -79,6 +79,14 @@ extern void rcu_init(void); (ptr)->next = NULL; (ptr)->func = NULL; \ } while (0) +static inline void init_rcu_head_on_stack(struct rcu_head *head) +{ +} + +static inline void destroy_rcu_head_on_stack(struct rcu_head *head) +{ +} + #ifdef CONFIG_DEBUG_LOCK_ALLOC extern struct lockdep_map rcu_lock_map; -- cgit v1.2.3-70-g09d2 From e3174cfd2a1e28fff774681f00a0eef3d31da970 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 11 May 2010 08:31:49 +0200 Subject: Revert "perf: Fix exit() vs PERF_FORMAT_GROUP" This reverts commit 4fd38e4595e2f6c9d27732c042a0e16b2753049c. It causes various crashes and hangs when events are activated. The cause is not fully understood yet but we need to revert it because the effects are severe. Reported-by: Stephane Eranian Reported-by: Lin Ming Cc: Peter Zijlstra Cc: Corey Ashford Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 1 - kernel/perf_event.c | 5 ----- 2 files changed, 6 deletions(-) (limited to 'include') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 4924c96d7e2..3fd5c82e0e1 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -575,7 +575,6 @@ struct pmu { * enum perf_event_active_state - the states of a event */ enum perf_event_active_state { - PERF_EVENT_STATE_FREE = -3, PERF_EVENT_STATE_ERROR = -2, PERF_EVENT_STATE_OFF = -1, PERF_EVENT_STATE_INACTIVE = 0, diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 180151ff837..a9047463fd8 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -334,9 +334,6 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) if (event->state > PERF_EVENT_STATE_OFF) event->state = PERF_EVENT_STATE_OFF; - if (event->state > PERF_EVENT_STATE_FREE) - return; - /* * If this was a group event with sibling events then * upgrade the siblings to singleton events by adding them @@ -1871,8 +1868,6 @@ int perf_event_release_kernel(struct perf_event *event) { struct perf_event_context *ctx = event->ctx; - event->state = PERF_EVENT_STATE_FREE; - WARN_ON_ONCE(ctx->parent_ctx); /* * There are two ways this annotation is useful: -- cgit v1.2.3-70-g09d2 From a93d2f1744206827ccf416e2cdc5018aa503314e Mon Sep 17 00:00:00 2001 From: Changli Gao Date: Fri, 7 May 2010 14:33:26 +0800 Subject: sched, wait: Use wrapper functions epoll should not touch flags in wait_queue_t. This patch introduces a new function __add_wait_queue_exclusive(), for the users, who use wait queue as a LIFO queue. __add_wait_queue_tail_exclusive() is introduced too instead of add_wait_queue_exclusive_locked(). remove_wait_queue_locked() is removed, as it is a duplicate of __remove_wait_queue(), disliked by users, and with less users. Signed-off-by: Changli Gao Signed-off-by: Peter Zijlstra Cc: Alexander Viro Cc: Paul Menage Cc: Li Zefan Cc: Davide Libenzi Cc: LKML-Reference: <1273214006-2979-1-git-send-email-xiaosuo@gmail.com> Signed-off-by: Ingo Molnar --- fs/eventpoll.c | 3 +-- include/linux/wait.h | 35 +++++++++++++++-------------------- kernel/cgroup.c | 2 +- kernel/sched.c | 3 +-- 4 files changed, 18 insertions(+), 25 deletions(-) (limited to 'include') diff --git a/fs/eventpoll.c b/fs/eventpoll.c index bd056a5b4ef..3817149919c 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1140,8 +1140,7 @@ retry: * ep_poll_callback() when events will become available. */ init_waitqueue_entry(&wait, current); - wait.flags |= WQ_FLAG_EXCLUSIVE; - __add_wait_queue(&ep->wq, &wait); + __add_wait_queue_exclusive(&ep->wq, &wait); for (;;) { /* diff --git a/include/linux/wait.h b/include/linux/wait.h index a48e16b77d5..76d96d035ea 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -127,12 +127,26 @@ static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new) /* * Used for wake-one threads: */ +static inline void __add_wait_queue_exclusive(wait_queue_head_t *q, + wait_queue_t *wait) +{ + wait->flags |= WQ_FLAG_EXCLUSIVE; + __add_wait_queue(q, wait); +} + static inline void __add_wait_queue_tail(wait_queue_head_t *head, - wait_queue_t *new) + wait_queue_t *new) { list_add_tail(&new->task_list, &head->task_list); } +static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q, + wait_queue_t *wait) +{ + wait->flags |= WQ_FLAG_EXCLUSIVE; + __add_wait_queue_tail(q, wait); +} + static inline void __remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old) { @@ -403,25 +417,6 @@ do { \ __ret; \ }) -/* - * Must be called with the spinlock in the wait_queue_head_t held. - */ -static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q, - wait_queue_t * wait) -{ - wait->flags |= WQ_FLAG_EXCLUSIVE; - __add_wait_queue_tail(q, wait); -} - -/* - * Must be called with the spinlock in the wait_queue_head_t held. - */ -static inline void remove_wait_queue_locked(wait_queue_head_t *q, - wait_queue_t * wait) -{ - __remove_wait_queue(q, wait); -} - /* * These are the old interfaces to sleep waiting for an event. * They are racy. DO NOT use them, use the wait_event* interfaces above. diff --git a/kernel/cgroup.c b/kernel/cgroup.c index e2769e13980..4a07d057a26 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -3010,7 +3010,7 @@ static int cgroup_event_wake(wait_queue_t *wait, unsigned mode, unsigned long flags = (unsigned long)key; if (flags & POLLHUP) { - remove_wait_queue_locked(event->wqh, &event->wait); + __remove_wait_queue(event->wqh, &event->wait); spin_lock(&cgrp->event_list_lock); list_del(&event->list); spin_unlock(&cgrp->event_list_lock); diff --git a/kernel/sched.c b/kernel/sched.c index 39aa9c7e22c..b531d793408 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3983,8 +3983,7 @@ do_wait_for_common(struct completion *x, long timeout, int state) if (!x->done) { DECLARE_WAITQUEUE(wait, current); - wait.flags |= WQ_FLAG_EXCLUSIVE; - __add_wait_queue_tail(&x->wait, &wait); + __add_wait_queue_tail_exclusive(&x->wait, &wait); do { if (signal_pending_state(state, current)) { timeout = -ERESTARTSYS; -- cgit v1.2.3-70-g09d2 From 72d5a9f7a9542f88397558c65bcfc3b115a65e34 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 10 May 2010 17:12:17 -0700 Subject: rcu: remove all rcu head initializations, except on_stack initializations Remove all rcu head inits. We don't care about the RCU head state before passing it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can keep track of objects on stack. Signed-off-by: Mathieu Desnoyers Signed-off-by: Paul E. McKenney --- include/linux/init_task.h | 1 - kernel/rcutiny.c | 6 ++++++ kernel/rcutorture.c | 2 ++ kernel/rcutree.c | 4 ++++ kernel/rcutree_plugin.h | 2 ++ 5 files changed, 14 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index b1ed1cd8e2a..7996fc2c9ba 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -49,7 +49,6 @@ extern struct group_info init_groups; { .first = &init_task.pids[PIDTYPE_PGID].node }, \ { .first = &init_task.pids[PIDTYPE_SID].node }, \ }, \ - .rcu = RCU_HEAD_INIT, \ .level = 0, \ .numbers = { { \ .nr = 0, \ diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c index b1804ff83d5..38729d3cd23 100644 --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -245,11 +245,13 @@ void rcu_barrier(void) { struct rcu_synchronize rcu; + init_rcu_head_on_stack(&rcu.head); init_completion(&rcu.completion); /* Will wake me after RCU finished. */ call_rcu(&rcu.head, wakeme_after_rcu); /* Wait for it. */ wait_for_completion(&rcu.completion); + destroy_rcu_head_on_stack(&rcu.head); } EXPORT_SYMBOL_GPL(rcu_barrier); @@ -257,11 +259,13 @@ void rcu_barrier_bh(void) { struct rcu_synchronize rcu; + init_rcu_head_on_stack(&rcu.head); init_completion(&rcu.completion); /* Will wake me after RCU finished. */ call_rcu_bh(&rcu.head, wakeme_after_rcu); /* Wait for it. */ wait_for_completion(&rcu.completion); + destroy_rcu_head_on_stack(&rcu.head); } EXPORT_SYMBOL_GPL(rcu_barrier_bh); @@ -269,11 +273,13 @@ void rcu_barrier_sched(void) { struct rcu_synchronize rcu; + init_rcu_head_on_stack(&rcu.head); init_completion(&rcu.completion); /* Will wake me after RCU finished. */ call_rcu_sched(&rcu.head, wakeme_after_rcu); /* Wait for it. */ wait_for_completion(&rcu.completion); + destroy_rcu_head_on_stack(&rcu.head); } EXPORT_SYMBOL_GPL(rcu_barrier_sched); diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 58df55bf83e..077defb3457 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -464,9 +464,11 @@ static void rcu_bh_torture_synchronize(void) { struct rcu_bh_torture_synchronize rcu; + init_rcu_head_on_stack(&rcu.head); init_completion(&rcu.completion); call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb); wait_for_completion(&rcu.completion); + destroy_rcu_head_on_stack(&rcu.head); } static struct rcu_torture_ops rcu_bh_ops = { diff --git a/kernel/rcutree.c b/kernel/rcutree.c index ba6996943e2..d4437345706 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1484,11 +1484,13 @@ void synchronize_sched(void) if (rcu_blocking_is_gp()) return; + init_rcu_head_on_stack(&rcu.head); init_completion(&rcu.completion); /* Will wake me after RCU finished. */ call_rcu_sched(&rcu.head, wakeme_after_rcu); /* Wait for it. */ wait_for_completion(&rcu.completion); + destroy_rcu_head_on_stack(&rcu.head); } EXPORT_SYMBOL_GPL(synchronize_sched); @@ -1508,11 +1510,13 @@ void synchronize_rcu_bh(void) if (rcu_blocking_is_gp()) return; + init_rcu_head_on_stack(&rcu.head); init_completion(&rcu.completion); /* Will wake me after RCU finished. */ call_rcu_bh(&rcu.head, wakeme_after_rcu); /* Wait for it. */ wait_for_completion(&rcu.completion); + destroy_rcu_head_on_stack(&rcu.head); } EXPORT_SYMBOL_GPL(synchronize_rcu_bh); diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index ac7d80fa895..0e4f420245d 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -557,11 +557,13 @@ void synchronize_rcu(void) if (!rcu_scheduler_active) return; + init_rcu_head_on_stack(&rcu.head); init_completion(&rcu.completion); /* Will wake me after RCU finished. */ call_rcu(&rcu.head, wakeme_after_rcu); /* Wait for it. */ wait_for_completion(&rcu.completion); + destroy_rcu_head_on_stack(&rcu.head); } EXPORT_SYMBOL_GPL(synchronize_rcu); -- cgit v1.2.3-70-g09d2 From d83c49f3e36cecd2e8823b6c48ffba083b8a5704 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 30 Apr 2010 17:17:09 -0400 Subject: Fix the regression created by "set S_DEAD on unlink()..." commit 1) i_flags simply doesn't work for mount/unlink race prevention; we may have many links to file and rm on one of those obviously shouldn't prevent bind on top of another later on. To fix it right way we need to mark _dentry_ as unsuitable for mounting upon; new flag (DCACHE_CANT_MOUNT) is protected by d_flags and i_mutex on the inode in question. Set it (with dont_mount(dentry)) in unlink/rmdir/etc., check (with cant_mount(dentry)) in places in namespace.c that used to check for S_DEAD. Setting S_DEAD is still needed in places where we used to set it (for directories getting killed), since we rely on it for readdir/rmdir race prevention. 2) rename()/mount() protection has another bogosity - we unhash the target before we'd checked that it's not a mountpoint. Fixed. 3) ancient bogosity in pivot_root() - we locked i_mutex on the right directory, but checked S_DEAD on the different (and wrong) one. Noticed and fixed. Signed-off-by: Al Viro --- drivers/usb/core/inode.c | 1 + fs/configfs/dir.c | 4 ++++ fs/namei.c | 21 +++++++++++++-------- fs/namespace.c | 6 +++--- include/linux/dcache.h | 14 ++++++++++++++ 5 files changed, 35 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c index 4a6366a4212..111a01a747f 100644 --- a/drivers/usb/core/inode.c +++ b/drivers/usb/core/inode.c @@ -380,6 +380,7 @@ static int usbfs_rmdir(struct inode *dir, struct dentry *dentry) mutex_lock(&inode->i_mutex); dentry_unhash(dentry); if (usbfs_empty(dentry)) { + dont_mount(dentry); drop_nlink(dentry->d_inode); drop_nlink(dentry->d_inode); dput(dentry); diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index 8e48b52205a..0b502f80c69 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -645,6 +645,7 @@ static void detach_groups(struct config_group *group) configfs_detach_group(sd->s_element); child->d_inode->i_flags |= S_DEAD; + dont_mount(child); mutex_unlock(&child->d_inode->i_mutex); @@ -840,6 +841,7 @@ static int configfs_attach_item(struct config_item *parent_item, mutex_lock(&dentry->d_inode->i_mutex); configfs_remove_dir(item); dentry->d_inode->i_flags |= S_DEAD; + dont_mount(dentry); mutex_unlock(&dentry->d_inode->i_mutex); d_delete(dentry); } @@ -882,6 +884,7 @@ static int configfs_attach_group(struct config_item *parent_item, if (ret) { configfs_detach_item(item); dentry->d_inode->i_flags |= S_DEAD; + dont_mount(dentry); } configfs_adjust_dir_dirent_depth_after_populate(sd); mutex_unlock(&dentry->d_inode->i_mutex); @@ -1725,6 +1728,7 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys) mutex_unlock(&configfs_symlink_mutex); configfs_detach_group(&group->cg_item); dentry->d_inode->i_flags |= S_DEAD; + dont_mount(dentry); mutex_unlock(&dentry->d_inode->i_mutex); d_delete(dentry); diff --git a/fs/namei.c b/fs/namei.c index 16df7277a92..b86b96fe1dc 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2176,8 +2176,10 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry) error = security_inode_rmdir(dir, dentry); if (!error) { error = dir->i_op->rmdir(dir, dentry); - if (!error) + if (!error) { dentry->d_inode->i_flags |= S_DEAD; + dont_mount(dentry); + } } } mutex_unlock(&dentry->d_inode->i_mutex); @@ -2261,7 +2263,7 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry) if (!error) { error = dir->i_op->unlink(dir, dentry); if (!error) - dentry->d_inode->i_flags |= S_DEAD; + dont_mount(dentry); } } mutex_unlock(&dentry->d_inode->i_mutex); @@ -2572,17 +2574,20 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, return error; target = new_dentry->d_inode; - if (target) { + if (target) mutex_lock(&target->i_mutex); - dentry_unhash(new_dentry); - } if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry)) error = -EBUSY; - else + else { + if (target) + dentry_unhash(new_dentry); error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); + } if (target) { - if (!error) + if (!error) { target->i_flags |= S_DEAD; + dont_mount(new_dentry); + } mutex_unlock(&target->i_mutex); if (d_unhashed(new_dentry)) d_rehash(new_dentry); @@ -2614,7 +2619,7 @@ static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); if (!error) { if (target) - target->i_flags |= S_DEAD; + dont_mount(new_dentry); if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) d_move(old_dentry, new_dentry); } diff --git a/fs/namespace.c b/fs/namespace.c index 8174c8ab5c7..f20cb57d106 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1432,7 +1432,7 @@ static int graft_tree(struct vfsmount *mnt, struct path *path) err = -ENOENT; mutex_lock(&path->dentry->d_inode->i_mutex); - if (IS_DEADDIR(path->dentry->d_inode)) + if (cant_mount(path->dentry)) goto out_unlock; err = security_sb_check_sb(mnt, path); @@ -1623,7 +1623,7 @@ static int do_move_mount(struct path *path, char *old_name) err = -ENOENT; mutex_lock(&path->dentry->d_inode->i_mutex); - if (IS_DEADDIR(path->dentry->d_inode)) + if (cant_mount(path->dentry)) goto out1; if (d_unlinked(path->dentry)) @@ -2234,7 +2234,7 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, if (!check_mnt(root.mnt)) goto out2; error = -ENOENT; - if (IS_DEADDIR(new.dentry->d_inode)) + if (cant_mount(old.dentry)) goto out2; if (d_unlinked(new.dentry)) goto out2; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 30b93b2a01a..eebb617c17d 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -186,6 +186,8 @@ d_iput: no no no yes #define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080 /* Parent inode is watched by some fsnotify listener */ +#define DCACHE_CANT_MOUNT 0x0100 + extern spinlock_t dcache_lock; extern seqlock_t rename_lock; @@ -358,6 +360,18 @@ static inline int d_unlinked(struct dentry *dentry) return d_unhashed(dentry) && !IS_ROOT(dentry); } +static inline int cant_mount(struct dentry *dentry) +{ + return (dentry->d_flags & DCACHE_CANT_MOUNT); +} + +static inline void dont_mount(struct dentry *dentry) +{ + spin_lock(&dentry->d_lock); + dentry->d_flags |= DCACHE_CANT_MOUNT; + spin_unlock(&dentry->d_lock); +} + static inline struct dentry *dget_parent(struct dentry *dentry) { struct dentry *ret; -- cgit v1.2.3-70-g09d2 From f3d46f9d3194e0329216002a8724d4c0957abc79 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Mon, 17 May 2010 14:33:53 +1000 Subject: atomic_t: Cast to volatile when accessing atomic variables In preparation for removing volatile from the atomic_t definition, this patch adds a volatile cast to all the atomic read functions. Signed-off-by: Anton Blanchard Signed-off-by: Linus Torvalds --- arch/alpha/include/asm/atomic.h | 4 ++-- arch/arm/include/asm/atomic.h | 2 +- arch/avr32/include/asm/atomic.h | 2 +- arch/cris/include/asm/atomic.h | 2 +- arch/frv/include/asm/atomic.h | 2 +- arch/h8300/include/asm/atomic.h | 2 +- arch/ia64/include/asm/atomic.h | 4 ++-- arch/m32r/include/asm/atomic.h | 2 +- arch/m68k/include/asm/atomic_mm.h | 2 +- arch/m68k/include/asm/atomic_no.h | 2 +- arch/mips/include/asm/atomic.h | 4 ++-- arch/mn10300/include/asm/atomic.h | 2 +- arch/parisc/include/asm/atomic.h | 4 ++-- arch/sh/include/asm/atomic.h | 2 +- arch/sparc/include/asm/atomic_32.h | 2 +- arch/sparc/include/asm/atomic_64.h | 4 ++-- arch/x86/include/asm/atomic.h | 2 +- arch/x86/include/asm/atomic64_64.h | 2 +- arch/xtensa/include/asm/atomic.h | 2 +- include/asm-generic/atomic.h | 2 +- 20 files changed, 25 insertions(+), 25 deletions(-) (limited to 'include') diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h index 610dff44d94..e756d04b6cd 100644 --- a/arch/alpha/include/asm/atomic.h +++ b/arch/alpha/include/asm/atomic.h @@ -17,8 +17,8 @@ #define ATOMIC_INIT(i) ( (atomic_t) { (i) } ) #define ATOMIC64_INIT(i) ( (atomic64_t) { (i) } ) -#define atomic_read(v) ((v)->counter + 0) -#define atomic64_read(v) ((v)->counter + 0) +#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic64_read(v) (*(volatile long *)&(v)->counter) #define atomic_set(v,i) ((v)->counter = (i)) #define atomic64_set(v,i) ((v)->counter = (i)) diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h index e8ddec2cb15..a0162fa9456 100644 --- a/arch/arm/include/asm/atomic.h +++ b/arch/arm/include/asm/atomic.h @@ -24,7 +24,7 @@ * strex/ldrex monitor on some implementations. The reason we can use it for * atomic_set() is the clrex or dummy strex done on every exception return. */ -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic_set(v,i) (((v)->counter) = (i)) #if __LINUX_ARM_ARCH__ >= 6 diff --git a/arch/avr32/include/asm/atomic.h b/arch/avr32/include/asm/atomic.h index b131c27ddf5..bbce6a1c6bb 100644 --- a/arch/avr32/include/asm/atomic.h +++ b/arch/avr32/include/asm/atomic.h @@ -19,7 +19,7 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic_set(v, i) (((v)->counter) = i) /* diff --git a/arch/cris/include/asm/atomic.h b/arch/cris/include/asm/atomic.h index a6aca819e9f..88dc9b9c4ba 100644 --- a/arch/cris/include/asm/atomic.h +++ b/arch/cris/include/asm/atomic.h @@ -15,7 +15,7 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic_set(v,i) (((v)->counter) = (i)) /* These should be written in asm but we do it in C for now. */ diff --git a/arch/frv/include/asm/atomic.h b/arch/frv/include/asm/atomic.h index 00a57af79af..fae32c7fdcb 100644 --- a/arch/frv/include/asm/atomic.h +++ b/arch/frv/include/asm/atomic.h @@ -36,7 +36,7 @@ #define smp_mb__after_atomic_inc() barrier() #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic_set(v, i) (((v)->counter) = (i)) #ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS diff --git a/arch/h8300/include/asm/atomic.h b/arch/h8300/include/asm/atomic.h index 33c8c0fa958..e936804b750 100644 --- a/arch/h8300/include/asm/atomic.h +++ b/arch/h8300/include/asm/atomic.h @@ -10,7 +10,7 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic_set(v, i) (((v)->counter) = i) #include diff --git a/arch/ia64/include/asm/atomic.h b/arch/ia64/include/asm/atomic.h index 88405cb0832..4e1948447a0 100644 --- a/arch/ia64/include/asm/atomic.h +++ b/arch/ia64/include/asm/atomic.h @@ -21,8 +21,8 @@ #define ATOMIC_INIT(i) ((atomic_t) { (i) }) #define ATOMIC64_INIT(i) ((atomic64_t) { (i) }) -#define atomic_read(v) ((v)->counter) -#define atomic64_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic64_read(v) (*(volatile long *)&(v)->counter) #define atomic_set(v,i) (((v)->counter) = (i)) #define atomic64_set(v,i) (((v)->counter) = (i)) diff --git a/arch/m32r/include/asm/atomic.h b/arch/m32r/include/asm/atomic.h index 63f0cf0f50d..d44a51e5271 100644 --- a/arch/m32r/include/asm/atomic.h +++ b/arch/m32r/include/asm/atomic.h @@ -26,7 +26,7 @@ * * Atomically reads the value of @v. */ -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) /** * atomic_set - set atomic variable diff --git a/arch/m68k/include/asm/atomic_mm.h b/arch/m68k/include/asm/atomic_mm.h index d9d2ed64743..6a223b3f7e7 100644 --- a/arch/m68k/include/asm/atomic_mm.h +++ b/arch/m68k/include/asm/atomic_mm.h @@ -15,7 +15,7 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic_set(v, i) (((v)->counter) = i) static inline void atomic_add(int i, atomic_t *v) diff --git a/arch/m68k/include/asm/atomic_no.h b/arch/m68k/include/asm/atomic_no.h index 5674cb9449b..289310c63a8 100644 --- a/arch/m68k/include/asm/atomic_no.h +++ b/arch/m68k/include/asm/atomic_no.h @@ -15,7 +15,7 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic_set(v, i) (((v)->counter) = i) static __inline__ void atomic_add(int i, atomic_t *v) diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h index 519197ede08..59dc0c7ef73 100644 --- a/arch/mips/include/asm/atomic.h +++ b/arch/mips/include/asm/atomic.h @@ -29,7 +29,7 @@ * * Atomically reads the value of @v. */ -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) /* * atomic_set - set atomic variable @@ -410,7 +410,7 @@ static __inline__ int atomic_add_unless(atomic_t *v, int a, int u) * @v: pointer of type atomic64_t * */ -#define atomic64_read(v) ((v)->counter) +#define atomic64_read(v) (*(volatile long *)&(v)->counter) /* * atomic64_set - set atomic variable diff --git a/arch/mn10300/include/asm/atomic.h b/arch/mn10300/include/asm/atomic.h index 5bf5be9566d..e41222d6c2f 100644 --- a/arch/mn10300/include/asm/atomic.h +++ b/arch/mn10300/include/asm/atomic.h @@ -31,7 +31,7 @@ * Atomically reads the value of @v. Note that the guaranteed * useful range of an atomic_t is only 24 bits. */ -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) /** * atomic_set - set atomic variable diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h index 716634d1f54..f81955934ae 100644 --- a/arch/parisc/include/asm/atomic.h +++ b/arch/parisc/include/asm/atomic.h @@ -189,7 +189,7 @@ static __inline__ void atomic_set(atomic_t *v, int i) static __inline__ int atomic_read(const atomic_t *v) { - return v->counter; + return (*(volatile int *)&(v)->counter); } /* exported interface */ @@ -286,7 +286,7 @@ atomic64_set(atomic64_t *v, s64 i) static __inline__ s64 atomic64_read(const atomic64_t *v) { - return v->counter; + return (*(volatile long *)&(v)->counter); } #define atomic64_add(i,v) ((void)(__atomic64_add_return( ((s64)(i)),(v)))) diff --git a/arch/sh/include/asm/atomic.h b/arch/sh/include/asm/atomic.h index 275a448ae8c..c7983124d99 100644 --- a/arch/sh/include/asm/atomic.h +++ b/arch/sh/include/asm/atomic.h @@ -13,7 +13,7 @@ #define ATOMIC_INIT(i) ( (atomic_t) { (i) } ) -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic_set(v,i) ((v)->counter = (i)) #if defined(CONFIG_GUSA_RB) diff --git a/arch/sparc/include/asm/atomic_32.h b/arch/sparc/include/asm/atomic_32.h index f0d343c3b95..7ae128b19d3 100644 --- a/arch/sparc/include/asm/atomic_32.h +++ b/arch/sparc/include/asm/atomic_32.h @@ -25,7 +25,7 @@ extern int atomic_cmpxchg(atomic_t *, int, int); extern int atomic_add_unless(atomic_t *, int, int); extern void atomic_set(atomic_t *, int); -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) #define atomic_add(i, v) ((void)__atomic_add_return( (int)(i), (v))) #define atomic_sub(i, v) ((void)__atomic_add_return(-(int)(i), (v))) diff --git a/arch/sparc/include/asm/atomic_64.h b/arch/sparc/include/asm/atomic_64.h index f2e48009989..2050ca02c42 100644 --- a/arch/sparc/include/asm/atomic_64.h +++ b/arch/sparc/include/asm/atomic_64.h @@ -13,8 +13,8 @@ #define ATOMIC_INIT(i) { (i) } #define ATOMIC64_INIT(i) { (i) } -#define atomic_read(v) ((v)->counter) -#define atomic64_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic64_read(v) (*(volatile long *)&(v)->counter) #define atomic_set(v, i) (((v)->counter) = i) #define atomic64_set(v, i) (((v)->counter) = i) diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h index 8f8217b9bda..37b39d27abe 100644 --- a/arch/x86/include/asm/atomic.h +++ b/arch/x86/include/asm/atomic.h @@ -22,7 +22,7 @@ */ static inline int atomic_read(const atomic_t *v) { - return v->counter; + return (*(volatile int *)&(v)->counter); } /** diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h index 51c5b405692..b014e235ea8 100644 --- a/arch/x86/include/asm/atomic64_64.h +++ b/arch/x86/include/asm/atomic64_64.h @@ -18,7 +18,7 @@ */ static inline long atomic64_read(const atomic64_t *v) { - return v->counter; + return (*(volatile long *)&(v)->counter); } /** diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h index 22d6dde4261..a96a0619d0b 100644 --- a/arch/xtensa/include/asm/atomic.h +++ b/arch/xtensa/include/asm/atomic.h @@ -46,7 +46,7 @@ * * Atomically reads the value of @v. */ -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) /** * atomic_set - set atomic variable diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h index c99c64dc5f3..c33749f95b3 100644 --- a/include/asm-generic/atomic.h +++ b/include/asm-generic/atomic.h @@ -33,7 +33,7 @@ * Atomically reads the value of @v. Note that the guaranteed * useful range of an atomic_t is only 24 bits. */ -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) (*(volatile int *)&(v)->counter) /** * atomic_set - set atomic variable -- cgit v1.2.3-70-g09d2 From 81880d603d00c645e0890d0a44d50711c503b72b Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Mon, 17 May 2010 14:34:57 +1000 Subject: atomic_t: Remove volatile from atomic_t definition When looking at a performance problem on PowerPC, I noticed some awful code generation: c00000000051fc98: 3b 60 00 01 li r27,1 ... c00000000051fca0: 3b 80 00 00 li r28,0 ... c00000000051fcdc: 93 61 00 70 stw r27,112(r1) c00000000051fce0: 93 81 00 74 stw r28,116(r1) c00000000051fce4: 81 21 00 70 lwz r9,112(r1) c00000000051fce8: 80 01 00 74 lwz r0,116(r1) c00000000051fcec: 7d 29 07 b4 extsw r9,r9 c00000000051fcf0: 7c 00 07 b4 extsw r0,r0 c00000000051fcf4: 7c 20 04 ac lwsync c00000000051fcf8: 7d 60 f8 28 lwarx r11,0,r31 c00000000051fcfc: 7c 0b 48 00 cmpw r11,r9 c00000000051fd00: 40 c2 00 10 bne- c00000000051fd10 c00000000051fd04: 7c 00 f9 2d stwcx. r0,0,r31 c00000000051fd08: 40 c2 ff f0 bne+ c00000000051fcf8 c00000000051fd0c: 4c 00 01 2c isync We create two constants, write them out to the stack, read them straight back in and sign extend them. What a mess. It turns out this bad code is a result of us defining atomic_t as a volatile int. We removed the volatile attribute from the powerpc atomic_t definition years ago, but commit ea435467500612636f8f4fb639ff6e76b2496e4b (atomic_t: unify all arch definitions) added it back in. To dig up an old quote from Linus: > The fact is, volatile on data structures is a bug. It's a wart in the C > language. It shouldn't be used. > > Volatile accesses in *code* can be ok, and if we have "atomic_read()" > expand to a "*(volatile int *)&(x)->value", then I'd be ok with that. > > But marking data structures volatile just makes the compiler screw up > totally, and makes code for initialization sequences etc much worse. And screw up it does :) With the volatile removed, we see much more reasonable code generation: c00000000051f5b8: 3b 60 00 01 li r27,1 ... c00000000051f5c0: 3b 80 00 00 li r28,0 ... c00000000051fc7c: 7c 20 04 ac lwsync c00000000051fc80: 7c 00 f8 28 lwarx r0,0,r31 c00000000051fc84: 7c 00 d8 00 cmpw r0,r27 c00000000051fc88: 40 c2 00 10 bne- c00000000051fc98 c00000000051fc8c: 7f 80 f9 2d stwcx. r28,0,r31 c00000000051fc90: 40 c2 ff f0 bne+ c00000000051fc80 c00000000051fc94: 4c 00 01 2c isync Six instructions less. Signed-off-by: Anton Blanchard Signed-off-by: Linus Torvalds --- include/linux/types.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/types.h b/include/linux/types.h index c42724f8c80..23d237a075e 100644 --- a/include/linux/types.h +++ b/include/linux/types.h @@ -188,12 +188,12 @@ typedef u32 phys_addr_t; typedef phys_addr_t resource_size_t; typedef struct { - volatile int counter; + int counter; } atomic_t; #ifdef CONFIG_64BIT typedef struct { - volatile long counter; + long counter; } atomic64_t; #endif -- cgit v1.2.3-70-g09d2 From 0b7f1a7efb38b551f5948a13d0b36e876ba536db Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 28 Jan 2009 21:01:02 +0100 Subject: platform: Make platform resource input parameters const Make the platform resource input parameters of platform_device_add_resources() and platform_device_register_simple() const, as the resources are copied and never modified. Signed-off-by: Geert Uytterhoeven Acked-by: Greg Kroah-Hartman --- drivers/base/platform.c | 4 ++-- include/linux/platform_device.h | 6 ++++-- 2 files changed, 6 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 4b4b565c835..c5fbe198fbd 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -187,7 +187,7 @@ EXPORT_SYMBOL_GPL(platform_device_alloc); * released. */ int platform_device_add_resources(struct platform_device *pdev, - struct resource *res, unsigned int num) + const struct resource *res, unsigned int num) { struct resource *r; @@ -367,7 +367,7 @@ EXPORT_SYMBOL_GPL(platform_device_unregister); */ struct platform_device *platform_device_register_simple(const char *name, int id, - struct resource *res, + const struct resource *res, unsigned int num) { struct platform_device *pdev; diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index 212da17d06a..5417944d368 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -44,12 +44,14 @@ extern int platform_get_irq_byname(struct platform_device *, const char *); extern int platform_add_devices(struct platform_device **, int); extern struct platform_device *platform_device_register_simple(const char *, int id, - struct resource *, unsigned int); + const struct resource *, unsigned int); extern struct platform_device *platform_device_register_data(struct device *, const char *, int, const void *, size_t); extern struct platform_device *platform_device_alloc(const char *name, int id); -extern int platform_device_add_resources(struct platform_device *pdev, struct resource *res, unsigned int num); +extern int platform_device_add_resources(struct platform_device *pdev, + const struct resource *res, + unsigned int num); extern int platform_device_add_data(struct platform_device *pdev, const void *data, size_t size); extern int platform_device_add(struct platform_device *pdev); extern void platform_device_del(struct platform_device *pdev); -- cgit v1.2.3-70-g09d2 From bf54a2b3c0dbf76136f00ff785bf6d8f6291311d Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 18 Nov 2008 21:13:53 +0100 Subject: m68k: amiga - Zorro bus modalias support Add Amiga Zorro bus modalias and uevent support Signed-off-by: Geert Uytterhoeven --- drivers/net/a2065.c | 1 + drivers/net/ariadne.c | 1 + drivers/net/hydra.c | 1 + drivers/net/zorro8390.c | 1 + drivers/scsi/zorro7xx.c | 1 + drivers/video/cirrusfb.c | 1 + drivers/video/fm2fb.c | 1 + drivers/zorro/zorro-driver.c | 24 ++++++++++++++++++++++++ drivers/zorro/zorro-sysfs.c | 11 +++++++++++ include/linux/mod_devicetable.h | 9 +++++++++ include/linux/zorro.h | 13 +------------ scripts/mod/file2alias.c | 14 ++++++++++++++ 12 files changed, 66 insertions(+), 12 deletions(-) (limited to 'include') diff --git a/drivers/net/a2065.c b/drivers/net/a2065.c index ed5e9742be2..a8f0512bad3 100644 --- a/drivers/net/a2065.c +++ b/drivers/net/a2065.c @@ -674,6 +674,7 @@ static struct zorro_device_id a2065_zorro_tbl[] __devinitdata = { { ZORRO_PROD_AMERISTAR_A2065 }, { 0 } }; +MODULE_DEVICE_TABLE(zorro, a2065_zorro_tbl); static struct zorro_driver a2065_driver = { .name = "a2065", diff --git a/drivers/net/ariadne.c b/drivers/net/ariadne.c index fa1a2354f5f..4b30a46486e 100644 --- a/drivers/net/ariadne.c +++ b/drivers/net/ariadne.c @@ -145,6 +145,7 @@ static struct zorro_device_id ariadne_zorro_tbl[] __devinitdata = { { ZORRO_PROD_VILLAGE_TRONIC_ARIADNE }, { 0 } }; +MODULE_DEVICE_TABLE(zorro, ariadne_zorro_tbl); static struct zorro_driver ariadne_driver = { .name = "ariadne", diff --git a/drivers/net/hydra.c b/drivers/net/hydra.c index 24724b4ad70..07d8e5b634f 100644 --- a/drivers/net/hydra.c +++ b/drivers/net/hydra.c @@ -71,6 +71,7 @@ static struct zorro_device_id hydra_zorro_tbl[] __devinitdata = { { ZORRO_PROD_HYDRA_SYSTEMS_AMIGANET }, { 0 } }; +MODULE_DEVICE_TABLE(zorro, hydra_zorro_tbl); static struct zorro_driver hydra_driver = { .name = "hydra", diff --git a/drivers/net/zorro8390.c b/drivers/net/zorro8390.c index 81c753a617a..9548cbb5012 100644 --- a/drivers/net/zorro8390.c +++ b/drivers/net/zorro8390.c @@ -102,6 +102,7 @@ static struct zorro_device_id zorro8390_zorro_tbl[] __devinitdata = { { ZORRO_PROD_INDIVIDUAL_COMPUTERS_X_SURF, }, { 0 } }; +MODULE_DEVICE_TABLE(zorro, zorro8390_zorro_tbl); static struct zorro_driver zorro8390_driver = { .name = "zorro8390", diff --git a/drivers/scsi/zorro7xx.c b/drivers/scsi/zorro7xx.c index 105449c15fa..e17764d7147 100644 --- a/drivers/scsi/zorro7xx.c +++ b/drivers/scsi/zorro7xx.c @@ -69,6 +69,7 @@ static struct zorro_device_id zorro7xx_zorro_tbl[] __devinitdata = { }, { 0 } }; +MODULE_DEVICE_TABLE(zorro, zorro7xx_zorro_tbl); static int __devinit zorro7xx_init_one(struct zorro_dev *z, const struct zorro_device_id *ent) diff --git a/drivers/video/cirrusfb.c b/drivers/video/cirrusfb.c index 8d8dfda2f86..6df7c54db0a 100644 --- a/drivers/video/cirrusfb.c +++ b/drivers/video/cirrusfb.c @@ -299,6 +299,7 @@ static const struct zorro_device_id cirrusfb_zorro_table[] = { }, { 0 } }; +MODULE_DEVICE_TABLE(zorro, cirrusfb_zorro_table); static const struct { zorro_id id2; diff --git a/drivers/video/fm2fb.c b/drivers/video/fm2fb.c index 6c91c61cdb6..1b0feb8e724 100644 --- a/drivers/video/fm2fb.c +++ b/drivers/video/fm2fb.c @@ -219,6 +219,7 @@ static struct zorro_device_id fm2fb_devices[] __devinitdata = { { ZORRO_PROD_HELFRICH_RAINBOW_II }, { 0 } }; +MODULE_DEVICE_TABLE(zorro, fm2fb_devices); static struct zorro_driver fm2fb_driver = { .name = "fm2fb", diff --git a/drivers/zorro/zorro-driver.c b/drivers/zorro/zorro-driver.c index 53180a37cc9..7ee2b6e7178 100644 --- a/drivers/zorro/zorro-driver.c +++ b/drivers/zorro/zorro-driver.c @@ -137,10 +137,34 @@ static int zorro_bus_match(struct device *dev, struct device_driver *drv) return 0; } +static int zorro_uevent(struct device *dev, struct kobj_uevent_env *env) +{ +#ifdef CONFIG_HOTPLUG + struct zorro_dev *z; + + if (!dev) + return -ENODEV; + + z = to_zorro_dev(dev); + if (!z) + return -ENODEV; + + if (add_uevent_var(env, "ZORRO_ID=%08X", z->id) || + add_uevent_var(env, "ZORRO_SLOT_NAME=%s", dev_name(dev)) || + add_uevent_var(env, "ZORRO_SLOT_ADDR=%04X", z->slotaddr) || + add_uevent_var(env, "MODALIAS=" ZORRO_DEVICE_MODALIAS_FMT, z->id)) + return -ENOMEM; + + return 0; +#else /* !CONFIG_HOTPLUG */ + return -ENODEV; +#endif /* !CONFIG_HOTPLUG */ +} struct bus_type zorro_bus_type = { .name = "zorro", .match = zorro_bus_match, + .uevent = zorro_uevent, .probe = zorro_device_probe, .remove = zorro_device_remove, }; diff --git a/drivers/zorro/zorro-sysfs.c b/drivers/zorro/zorro-sysfs.c index 1d2a772ea14..eb924e0a64c 100644 --- a/drivers/zorro/zorro-sysfs.c +++ b/drivers/zorro/zorro-sysfs.c @@ -77,6 +77,16 @@ static struct bin_attribute zorro_config_attr = { .read = zorro_read_config, }; +static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct zorro_dev *z = to_zorro_dev(dev); + + return sprintf(buf, ZORRO_DEVICE_MODALIAS_FMT "\n", z->id); +} + +static DEVICE_ATTR(modalias, S_IRUGO, modalias_show, NULL); + int zorro_create_sysfs_dev_files(struct zorro_dev *z) { struct device *dev = &z->dev; @@ -89,6 +99,7 @@ int zorro_create_sysfs_dev_files(struct zorro_dev *z) (error = device_create_file(dev, &dev_attr_slotaddr)) || (error = device_create_file(dev, &dev_attr_slotsize)) || (error = device_create_file(dev, &dev_attr_resource)) || + (error = device_create_file(dev, &dev_attr_modalias)) || (error = sysfs_create_bin_file(&dev->kobj, &zorro_config_attr))) return error; diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h index f58e9d836f3..56fde4364e4 100644 --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -474,4 +474,13 @@ struct platform_device_id { __attribute__((aligned(sizeof(kernel_ulong_t)))); }; +struct zorro_device_id { + __u32 id; /* Device ID or ZORRO_WILDCARD */ + kernel_ulong_t driver_data; /* Data private to the driver */ +}; + +#define ZORRO_WILDCARD (0xffffffff) /* not official */ + +#define ZORRO_DEVICE_MODALIAS_FMT "zorro:i%08X" + #endif /* LINUX_MOD_DEVICETABLE_H */ diff --git a/include/linux/zorro.h b/include/linux/zorro.h index 913bfc226dd..908db1b36d6 100644 --- a/include/linux/zorro.h +++ b/include/linux/zorro.h @@ -38,8 +38,6 @@ typedef __u32 zorro_id; -#define ZORRO_WILDCARD (0xffffffff) /* not official */ - /* Include the ID list */ #include @@ -116,6 +114,7 @@ struct ConfigDev { #include #include +#include #include @@ -154,16 +153,6 @@ extern struct zorro_bus zorro_bus; /* single Zorro bus */ extern struct bus_type zorro_bus_type; - /* - * Zorro device IDs - */ - -struct zorro_device_id { - zorro_id id; /* Device ID or ZORRO_WILDCARD */ - unsigned long driver_data; /* Data private to the driver */ -}; - - /* * Zorro device drivers */ diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index 220213e603d..df90f31d14b 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -796,6 +796,16 @@ static int do_platform_entry(const char *filename, return 1; } +/* Looks like: zorro:iN. */ +static int do_zorro_entry(const char *filename, struct zorro_device_id *id, + char *alias) +{ + id->id = TO_NATIVE(id->id); + strcpy(alias, "zorro:"); + ADD(alias, "i", id->id != ZORRO_WILDCARD, id->id); + return 1; +} + /* Ignore any prefix, eg. some architectures prepend _ */ static inline int sym_is(const char *symbol, const char *name) { @@ -943,6 +953,10 @@ void handle_moddevtable(struct module *mod, struct elf_info *info, do_table(symval, sym->st_size, sizeof(struct platform_device_id), "platform", do_platform_entry, mod); + else if (sym_is(symname, "__mod_zorro_device_table")) + do_table(symval, sym->st_size, + sizeof(struct zorro_device_id), "zorro", + do_zorro_entry, mod); free(zeros); } -- cgit v1.2.3-70-g09d2 From 0d305464aefff342c85b4db8b3d7a4345246e5a1 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Sun, 5 Apr 2009 12:40:41 +0200 Subject: m68k: amiga - Zorro host bridge platform device conversion Signed-off-by: Geert Uytterhoeven --- arch/m68k/amiga/Makefile | 2 +- arch/m68k/amiga/platform.c | 58 +++++++++++ drivers/zorro/proc.c | 6 +- drivers/zorro/zorro.c | 243 ++++++++++++++++++++++++--------------------- include/linux/zorro.h | 9 -- 5 files changed, 190 insertions(+), 128 deletions(-) create mode 100644 arch/m68k/amiga/platform.c (limited to 'include') diff --git a/arch/m68k/amiga/Makefile b/arch/m68k/amiga/Makefile index 6a0d7650f98..11dd30b16b3 100644 --- a/arch/m68k/amiga/Makefile +++ b/arch/m68k/amiga/Makefile @@ -2,6 +2,6 @@ # Makefile for Linux arch/m68k/amiga source directory # -obj-y := config.o amiints.o cia.o chipram.o amisound.o +obj-y := config.o amiints.o cia.o chipram.o amisound.o platform.o obj-$(CONFIG_AMIGA_PCMCIA) += pcmcia.o diff --git a/arch/m68k/amiga/platform.c b/arch/m68k/amiga/platform.c new file mode 100644 index 00000000000..33a7669b441 --- /dev/null +++ b/arch/m68k/amiga/platform.c @@ -0,0 +1,58 @@ +/* + * Copyright (C) 2007-2009 Geert Uytterhoeven + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +#include +#include +#include + +#include + + +#ifdef CONFIG_ZORRO + +static const struct resource zorro_resources[] __initconst = { + /* Zorro II regions (on Zorro II/III) */ + { + .name = "Zorro II exp", + .start = 0x00e80000, + .end = 0x00efffff, + .flags = IORESOURCE_MEM, + }, { + .name = "Zorro II mem", + .start = 0x00200000, + .end = 0x009fffff, + .flags = IORESOURCE_MEM, + }, + /* Zorro III regions (on Zorro III only) */ + { + .name = "Zorro III exp", + .start = 0xff000000, + .end = 0xffffffff, + .flags = IORESOURCE_MEM, + }, { + .name = "Zorro III cfg", + .start = 0x40000000, + .end = 0x7fffffff, + .flags = IORESOURCE_MEM, + } +}; + + +static int __init amiga_init_bus(void) +{ + if (!MACH_IS_AMIGA || !AMIGAHW_PRESENT(ZORRO)) + return -ENODEV; + + platform_device_register_simple("amiga-zorro", -1, zorro_resources, + AMIGAHW_PRESENT(ZORRO3) ? 4 : 2); + return 0; +} + +subsys_initcall(amiga_init_bus); + +#endif /* CONFIG_ZORRO */ diff --git a/drivers/zorro/proc.c b/drivers/zorro/proc.c index d47c47fc048..3c7046d7965 100644 --- a/drivers/zorro/proc.c +++ b/drivers/zorro/proc.c @@ -97,7 +97,7 @@ static void zorro_seq_stop(struct seq_file *m, void *v) static int zorro_seq_show(struct seq_file *m, void *v) { - u_int slot = *(loff_t *)v; + unsigned int slot = *(loff_t *)v; struct zorro_dev *z = &zorro_autocon[slot]; seq_printf(m, "%02x\t%08x\t%08lx\t%08lx\t%02x\n", slot, z->id, @@ -129,7 +129,7 @@ static const struct file_operations zorro_devices_proc_fops = { static struct proc_dir_entry *proc_bus_zorro_dir; -static int __init zorro_proc_attach_device(u_int slot) +static int __init zorro_proc_attach_device(unsigned int slot) { struct proc_dir_entry *entry; char name[4]; @@ -146,7 +146,7 @@ static int __init zorro_proc_attach_device(u_int slot) static int __init zorro_proc_init(void) { - u_int slot; + unsigned int slot; if (MACH_IS_AMIGA && AMIGAHW_PRESENT(ZORRO)) { proc_bus_zorro_dir = proc_mkdir("bus/zorro", NULL); diff --git a/drivers/zorro/zorro.c b/drivers/zorro/zorro.c index d45fb34e2d2..6455f3a244c 100644 --- a/drivers/zorro/zorro.c +++ b/drivers/zorro/zorro.c @@ -15,6 +15,8 @@ #include #include #include +#include +#include #include #include @@ -26,24 +28,17 @@ * Zorro Expansion Devices */ -u_int zorro_num_autocon = 0; +unsigned int zorro_num_autocon; struct zorro_dev zorro_autocon[ZORRO_NUM_AUTO]; /* - * Single Zorro bus + * Zorro bus */ -struct zorro_bus zorro_bus = {\ - .resources = { - /* Zorro II regions (on Zorro II/III) */ - { .name = "Zorro II exp", .start = 0x00e80000, .end = 0x00efffff }, - { .name = "Zorro II mem", .start = 0x00200000, .end = 0x009fffff }, - /* Zorro III regions (on Zorro III only) */ - { .name = "Zorro III exp", .start = 0xff000000, .end = 0xffffffff }, - { .name = "Zorro III cfg", .start = 0x40000000, .end = 0x7fffffff } - }, - .name = "Zorro bus" +struct zorro_bus { + struct list_head devices; /* list of devices on this bus */ + struct device dev; }; @@ -53,18 +48,19 @@ struct zorro_bus zorro_bus = {\ struct zorro_dev *zorro_find_device(zorro_id id, struct zorro_dev *from) { - struct zorro_dev *z; + struct zorro_dev *z; - if (!MACH_IS_AMIGA || !AMIGAHW_PRESENT(ZORRO)) - return NULL; + if (!zorro_num_autocon) + return NULL; - for (z = from ? from+1 : &zorro_autocon[0]; - z < zorro_autocon+zorro_num_autocon; - z++) - if (id == ZORRO_WILDCARD || id == z->id) - return z; - return NULL; + for (z = from ? from+1 : &zorro_autocon[0]; + z < zorro_autocon+zorro_num_autocon; + z++) + if (id == ZORRO_WILDCARD || id == z->id) + return z; + return NULL; } +EXPORT_SYMBOL(zorro_find_device); /* @@ -83,121 +79,138 @@ struct zorro_dev *zorro_find_device(zorro_id id, struct zorro_dev *from) */ DECLARE_BITMAP(zorro_unused_z2ram, 128); +EXPORT_SYMBOL(zorro_unused_z2ram); static void __init mark_region(unsigned long start, unsigned long end, int flag) { - if (flag) - start += Z2RAM_CHUNKMASK; - else - end += Z2RAM_CHUNKMASK; - start &= ~Z2RAM_CHUNKMASK; - end &= ~Z2RAM_CHUNKMASK; - - if (end <= Z2RAM_START || start >= Z2RAM_END) - return; - start = start < Z2RAM_START ? 0x00000000 : start-Z2RAM_START; - end = end > Z2RAM_END ? Z2RAM_SIZE : end-Z2RAM_START; - while (start < end) { - u32 chunk = start>>Z2RAM_CHUNKSHIFT; if (flag) - set_bit(chunk, zorro_unused_z2ram); + start += Z2RAM_CHUNKMASK; else - clear_bit(chunk, zorro_unused_z2ram); - start += Z2RAM_CHUNKSIZE; - } + end += Z2RAM_CHUNKMASK; + start &= ~Z2RAM_CHUNKMASK; + end &= ~Z2RAM_CHUNKMASK; + + if (end <= Z2RAM_START || start >= Z2RAM_END) + return; + start = start < Z2RAM_START ? 0x00000000 : start-Z2RAM_START; + end = end > Z2RAM_END ? Z2RAM_SIZE : end-Z2RAM_START; + while (start < end) { + u32 chunk = start>>Z2RAM_CHUNKSHIFT; + if (flag) + set_bit(chunk, zorro_unused_z2ram); + else + clear_bit(chunk, zorro_unused_z2ram); + start += Z2RAM_CHUNKSIZE; + } } -static struct resource __init *zorro_find_parent_resource(struct zorro_dev *z) +static struct resource __init *zorro_find_parent_resource( + struct platform_device *bridge, struct zorro_dev *z) { - int i; + int i; - for (i = 0; i < zorro_bus.num_resources; i++) - if (zorro_resource_start(z) >= zorro_bus.resources[i].start && - zorro_resource_end(z) <= zorro_bus.resources[i].end) - return &zorro_bus.resources[i]; - return &iomem_resource; + for (i = 0; i < bridge->num_resources; i++) { + struct resource *r = &bridge->resource[i]; + if (zorro_resource_start(z) >= r->start && + zorro_resource_end(z) <= r->end) + return r; + } + return &iomem_resource; } - /* - * Initialization - */ -static int __init zorro_init(void) +static int __init amiga_zorro_probe(struct platform_device *pdev) { - struct zorro_dev *z; - unsigned int i; - int error; - - if (!MACH_IS_AMIGA || !AMIGAHW_PRESENT(ZORRO)) - return 0; - - pr_info("Zorro: Probing AutoConfig expansion devices: %d device%s\n", - zorro_num_autocon, zorro_num_autocon == 1 ? "" : "s"); - - /* Initialize the Zorro bus */ - INIT_LIST_HEAD(&zorro_bus.devices); - dev_set_name(&zorro_bus.dev, "zorro"); - error = device_register(&zorro_bus.dev); - if (error) { - pr_err("Zorro: Error registering zorro_bus\n"); - return error; - } - - /* Request the resources */ - zorro_bus.num_resources = AMIGAHW_PRESENT(ZORRO3) ? 4 : 2; - for (i = 0; i < zorro_bus.num_resources; i++) - request_resource(&iomem_resource, &zorro_bus.resources[i]); - - /* Register all devices */ - for (i = 0; i < zorro_num_autocon; i++) { - z = &zorro_autocon[i]; - z->id = (z->rom.er_Manufacturer<<16) | (z->rom.er_Product<<8); - if (z->id == ZORRO_PROD_GVP_EPC_BASE) { - /* GVP quirk */ - unsigned long magic = zorro_resource_start(z)+0x8000; - z->id |= *(u16 *)ZTWO_VADDR(magic) & GVP_PRODMASK; - } - sprintf(z->name, "Zorro device %08x", z->id); - zorro_name_device(z); - z->resource.name = z->name; - if (request_resource(zorro_find_parent_resource(z), &z->resource)) - pr_err("Zorro: Address space collision on device %s %pR\n", - z->name, &z->resource); - dev_set_name(&z->dev, "%02x", i); - z->dev.parent = &zorro_bus.dev; - z->dev.bus = &zorro_bus_type; - error = device_register(&z->dev); + struct zorro_bus *bus; + struct zorro_dev *z; + struct resource *r; + unsigned int i; + int error; + + /* Initialize the Zorro bus */ + bus = kzalloc(sizeof(*bus), GFP_KERNEL); + if (!bus) + return -ENOMEM; + + INIT_LIST_HEAD(&bus->devices); + bus->dev.parent = &pdev->dev; + dev_set_name(&bus->dev, "zorro"); + error = device_register(&bus->dev); if (error) { - pr_err("Zorro: Error registering device %s\n", z->name); - continue; + pr_err("Zorro: Error registering zorro_bus\n"); + kfree(bus); + return error; } - error = zorro_create_sysfs_dev_files(z); - if (error) - dev_err(&z->dev, "Error creating sysfs files\n"); - } - - /* Mark all available Zorro II memory */ - zorro_for_each_dev(z) { - if (z->rom.er_Type & ERTF_MEMLIST) - mark_region(zorro_resource_start(z), zorro_resource_end(z)+1, 1); - } - - /* Unmark all used Zorro II memory */ - for (i = 0; i < m68k_num_memory; i++) - if (m68k_memory[i].addr < 16*1024*1024) - mark_region(m68k_memory[i].addr, - m68k_memory[i].addr+m68k_memory[i].size, 0); - - return 0; + platform_set_drvdata(pdev, bus); + + /* Register all devices */ + pr_info("Zorro: Probing AutoConfig expansion devices: %u device%s\n", + zorro_num_autocon, zorro_num_autocon == 1 ? "" : "s"); + + for (i = 0; i < zorro_num_autocon; i++) { + z = &zorro_autocon[i]; + z->id = (z->rom.er_Manufacturer<<16) | (z->rom.er_Product<<8); + if (z->id == ZORRO_PROD_GVP_EPC_BASE) { + /* GVP quirk */ + unsigned long magic = zorro_resource_start(z)+0x8000; + z->id |= *(u16 *)ZTWO_VADDR(magic) & GVP_PRODMASK; + } + sprintf(z->name, "Zorro device %08x", z->id); + zorro_name_device(z); + z->resource.name = z->name; + r = zorro_find_parent_resource(pdev, z); + error = request_resource(r, &z->resource); + if (error) + dev_err(&bus->dev, + "Address space collision on device %s %pR\n", + z->name, &z->resource); + dev_set_name(&z->dev, "%02x", i); + z->dev.parent = &bus->dev; + z->dev.bus = &zorro_bus_type; + error = device_register(&z->dev); + if (error) { + dev_err(&bus->dev, "Error registering device %s\n", + z->name); + continue; + } + error = zorro_create_sysfs_dev_files(z); + if (error) + dev_err(&z->dev, "Error creating sysfs files\n"); + } + + /* Mark all available Zorro II memory */ + zorro_for_each_dev(z) { + if (z->rom.er_Type & ERTF_MEMLIST) + mark_region(zorro_resource_start(z), + zorro_resource_end(z)+1, 1); + } + + /* Unmark all used Zorro II memory */ + for (i = 0; i < m68k_num_memory; i++) + if (m68k_memory[i].addr < 16*1024*1024) + mark_region(m68k_memory[i].addr, + m68k_memory[i].addr+m68k_memory[i].size, + 0); + + return 0; } -subsys_initcall(zorro_init); +static struct platform_driver amiga_zorro_driver = { + .driver = { + .name = "amiga-zorro", + .owner = THIS_MODULE, + }, +}; -EXPORT_SYMBOL(zorro_find_device); -EXPORT_SYMBOL(zorro_unused_z2ram); +static int __init amiga_zorro_init(void) +{ + return platform_driver_probe(&amiga_zorro_driver, amiga_zorro_probe); +} + +module_init(amiga_zorro_init); MODULE_LICENSE("GPL"); diff --git a/include/linux/zorro.h b/include/linux/zorro.h index 908db1b36d6..7bf9db525e9 100644 --- a/include/linux/zorro.h +++ b/include/linux/zorro.h @@ -141,15 +141,6 @@ struct zorro_dev { * Zorro bus */ -struct zorro_bus { - struct list_head devices; /* list of devices on this bus */ - unsigned int num_resources; /* number of resources */ - struct resource resources[4]; /* address space routed to this bus */ - struct device dev; - char name[10]; -}; - -extern struct zorro_bus zorro_bus; /* single Zorro bus */ extern struct bus_type zorro_bus_type; -- cgit v1.2.3-70-g09d2