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2010-10-22Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
2010-10-22Merge branch 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds
* 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: (30 commits) BKL: remove BKL from freevxfs BKL: remove BKL from qnx4 autofs4: Only declare function when CONFIG_COMPAT is defined autofs: Only declare function when CONFIG_COMPAT is defined ncpfs: Lock socket in ncpfs while setting its callbacks fs/locks.c: prepare for BKL removal BKL: Remove BKL from ncpfs BKL: Remove BKL from OCFS2 BKL: Remove BKL from squashfs BKL: Remove BKL from jffs2 BKL: Remove BKL from ecryptfs BKL: Remove BKL from afs BKL: Remove BKL from USB gadgetfs BKL: Remove BKL from autofs4 BKL: Remove BKL from isofs BKL: Remove BKL from fat BKL: Remove BKL from ext2 filesystem BKL: Remove BKL from do_new_mount() BKL: Remove BKL from cgroup BKL: Remove BKL from NTFS ...
2010-10-22Merge branch 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: BKL: introduce CONFIG_BKL. dabusb: remove the BKL sunrpc: remove the big kernel lock init/main.c: remove BKL notations blktrace: remove the big kernel lock rtmutex-tester: make it build without BKL dvb-core: kill the big kernel lock dvb/bt8xx: kill the big kernel lock tlclk: remove big kernel lock fix rawctl compat ioctls breakage on amd64 and itanic uml: kill big kernel lock parisc: remove big kernel lock cris: autoconvert trivial BKL users alpha: kill big kernel lock isapnp: BKL removal s390/block: kill the big kernel lock hpet: kill BKL, add compat_ioctl
2010-10-21Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (71 commits) powerpc/44x: Update ppc44x_defconfig powerpc/watchdog: Make default timeout for Book-E watchdog a Kconfig option fsl_rio: Add comments for sRIO registers. powerpc/fsl-booke: Add e55xx (64-bit) smp defconfig powerpc/fsl-booke: Add p5020 DS board support powerpc/fsl-booke64: Use TLB CAMs to cover linear mapping on FSL 64-bit chips powerpc/fsl-booke: Add support for FSL Arch v1.0 MMU in setup_page_sizes powerpc/fsl-booke: Add support for FSL 64-bit e5500 core powerpc/85xx: add cache-sram support powerpc/85xx: add ngPIXIS FPGA device tree node to the P1022DS board powerpc: Fix compile error with paca code on ppc64e powerpc/fsl-booke: Add p3041 DS board support oprofile/fsl emb: Don't set MSR[PMM] until after clearing the interrupt. powerpc/fsl-booke: Add PCI device ids for P2040/P3041/P5010/P5020 QoirQ chips powerpc/mpc8xxx_gpio: Add support for 'qoriq-gpio' controllers powerpc/fsl_booke: Add support to boot from core other than 0 powerpc/p1022: Add probing for individual DMA channels powerpc/fsl_soc: Search all global-utilities nodes for rstccr powerpc: Fix invalid page flags in create TLB CAM path for PTE_64BIT powerpc/mpc83xx: Support for MPC8308 P1M board ... Fix up conflict with the generic irq_work changes in arch/powerpc/kernel/time.c
2010-10-21Merge branch 'core-memblock-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (74 commits) x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S xen: Cope with unmapped pages when initializing kernel pagetable memblock, bootmem: Round pfn properly for memory and reserved regions memblock: Annotate memblock functions with __init_memblock memblock: Allow memblock_init to be called early memblock/arm: Fix memblock_region_is_memory() typo x86, memblock: Remove __memblock_x86_find_in_range_size() memblock: Fix wraparound in find_region() x86-32, memblock: Make add_highpages honor early reserved ranges x86, memblock: Fix crashkernel allocation arm, memblock: Fix the sparsemem build memblock: Fix section mismatch warnings powerpc, memblock: Fix memblock API change fallout memblock, microblaze: Fix memblock API change fallout x86: Remove old bootmem code x86, memblock: Use memblock_memory_size()/memblock_free_memory_size() to get correct dma_reserve x86: Remove not used early_res code x86, memblock: Replace e820_/_early string with memblock_ x86: Use memblock to replace early_res x86, memblock: Use memblock_debug to control debug message print out ... Fix up trivial conflicts in arch/x86/kernel/setup.c and kernel/Makefile
2010-10-21Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (278 commits) arm: remove machine_desc.io_pg_offst and .phys_io arm: use addruart macro to establish debug mappings arm: return both physical and virtual addresses from addruart arm/debug: consolidate addruart macros for CONFIG_DEBUG_ICEDCC ARM: make struct machine_desc definition coherent with its comment eukrea_mbimxsd-baseboard: Pass the correct GPIO to gpio_free cpuimx27: fix compile when ULPI is selected mach-pcm037_eet: fix compile errors Fixing ethernet driver compilation error for i.MX31 ADS board cpuimx51: update board support mx5: add cpuimx51sd module and its baseboard iomux-mx51: fix GPIO_1_xx 's IOMUX configuration imx-esdhc: update devices registration mx51: add resources for SD/MMC on i.MX51 iomux-mx51: fix SD1 and SD2's iomux configuration clock-mx51: rename CLOCK1 to CLOCK_CCGR for better readability clock-mx51: factorize clk_set_parent and clk_get_rate eukrea_mbimxsd: add support for DVI displays cpuimx25 & cpuimx35: fix OTG port registration in host mode i.MX31 and i.MX35 : fix errate TLSbo65953 and ENGcm09472 ...
2010-10-21Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: (26 commits) PM / Wakeup: Show wakeup sources statistics in debugfs PM: Introduce library for device-specific OPPs (v7) PM: Add sysfs attr for rechecking dev hash from PM trace PM: Lock PM device list mutex in show_dev_hash() PM / Runtime: Remove idle notification after failing suspend PM / Hibernate: Modify signature used to mark swap PM / Runtime: Reduce code duplication in core helper functions PM: Allow wakeup events to abort freezing of tasks PM: runtime: add missed pm_request_autosuspend PM / Hibernate: Make some boot messages look less scary PM / Runtime: Implement autosuspend support PM / Runtime: Add no_callbacks flag PM / Runtime: Combine runtime PM entry points PM / Runtime: Merge synchronous and async runtime routines PM / Runtime: Replace boolean arguments with bitflags PM / Runtime: Move code in drivers/base/power/runtime.c sysfs: Add sysfs_merge_group() and sysfs_unmerge_group() PM: Fix potential issue with failing asynchronous suspend PM / Wakeup: Introduce wakeup source objects and event statistics (v3) PM: Fix signed/unsigned warning in dpm_show_time() ...
2010-10-21Merge branch 'irq-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (96 commits) apic, x86: Use BIOS settings for IBS and MCE threshold interrupt LVT offsets apic, x86: Check if EILVT APIC registers are available (AMD only) x86: ioapic: Call free_irte only if interrupt remapping enabled arm: Use ARCH_IRQ_INIT_FLAGS genirq, ARM: Fix boot on ARM platforms genirq: Fix CONFIG_GENIRQ_NO_DEPRECATED=y build x86: Switch sparse_irq allocations to GFP_KERNEL genirq: Switch sparse_irq allocator to GFP_KERNEL genirq: Make sparse_lock a mutex x86: lguest: Use new irq allocator genirq: Remove the now unused sparse irq leftovers genirq: Sanitize dynamic irq handling genirq: Remove arch_init_chip_data() x86: xen: Sanitise sparse_irq handling x86: Use sane enumeration x86: uv: Clean up the direct access to irq_desc x86: Make io_apic.c local functions static genirq: Remove irq_2_iommu x86: Speed up the irq_remapped check in hot pathes intr_remap: Simplify the code further ... Fix up trivial conflicts in arch/x86/Kconfig
2010-10-21Merge branch 'timers-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: ntp: Clamp PLL update interval
2010-10-21Merge branch 'futexes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: Fix kernel-doc notation & typos futex: Add lock context annotations futex: Mark restart_block.futex.uaddr[2] __user futex: Change 3rd arg of fetch_robust_entry() to unsigned int*
2010-10-21Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: Fix errors in nested key ref-counting
2010-10-21Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (29 commits) sched: Export account_system_vtime() sched: Call tick_check_idle before __irq_enter sched: Remove irq time from available CPU power sched: Do not account irq time to current task x86: Add IRQ_TIME_ACCOUNTING sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time sched: Add a PF flag for ksoftirqd identification sched: Consolidate account_system_vtime extern declaration sched: Fix softirq time accounting sched: Drop group_capacity to 1 only if local group has extra capacity sched: Force balancing on newidle balance if local group has capacity sched: Set group_imb only a task can be pulled from the busiest cpu sched: Do not consider SCHED_IDLE tasks to be cache hot sched: Drop all load weight manipulation for RT tasks sched: Create special class for stop/migrate work sched: Unindent labels sched: Comment updates: fix default latency and granularity numbers tracing/sched: Add sched_pi_setprio tracepoint sched: Give CPU bound RT tasks preference sched: Try not to migrate higher priority RT tasks ...
2010-10-21Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (163 commits) tracing: Fix compile issue for trace_sched_wakeup.c [S390] hardirq: remove pointless header file includes [IA64] Move local_softirq_pending() definition perf, powerpc: Fix power_pmu_event_init to not use event->ctx ftrace: Remove recursion between recordmcount and scripts/mod/empty jump_label: Add COND_STMT(), reducer wrappery perf: Optimize sw events perf: Use jump_labels to optimize the scheduler hooks jump_label: Add atomic_t interface jump_label: Use more consistent naming perf, hw_breakpoint: Fix crash in hw_breakpoint creation perf: Find task before event alloc perf: Fix task refcount bugs perf: Fix group moving irq_work: Add generic hardirq context callbacks perf_events: Fix transaction recovery in group_sched_in() perf_events: Fix bogus AMD64 generic TLB events perf_events: Fix bogus context time tracking tracing: Remove parent recording in latency tracer graph options tracing: Use one prologue for the preempt irqs off tracer function tracers ...
2010-10-21Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (52 commits) sched: fix RCU lockdep splat from task_group() rcu: using ACCESS_ONCE() to observe the jiffies_stall/rnp->qsmask value sched: suppress RCU lockdep splat in task_fork_fair net: suppress RCU lockdep false positive in sock_update_classid rcu: move check from rcu_dereference_bh to rcu_read_lock_bh_held rcu: Add advice to PROVE_RCU_REPEATEDLY kernel config parameter rcu: Add tracing data to support queueing models rcu: fix sparse errors in rcutorture.c rcu: only one evaluation of arg in rcu_dereference_check() unless sparse kernel: Remove undead ifdef CONFIG_DEBUG_LOCK_ALLOC rcu: fix _oddness handling of verbose stall warnings rcu: performance fixes to TINY_PREEMPT_RCU callback checking rcu: upgrade stallwarn.txt documentation for CPU-bound RT processes vhost: add __rcu annotations rcu: add comment stating that list_empty() applies to RCU-protected lists rcu: apply TINY_PREEMPT_RCU read-side speedup to TREE_PREEMPT_RCU rcu: combine duplicate code, courtesy of CONFIG_PREEMPT_RCU rcu: Upgrade srcu_read_lock() docbook about SRCU grace periods rcu: document ways of stalling updates in low-memory situations rcu: repair code-duplication FIXMEs ...
2010-10-21Merge branch 'core-locking-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: lockdep: Check the depth of subclass lockdep: Add improved subclass caching affs: Use sema_init instead of init_MUTEX hfs: Convert tree_lock to mutex arm: Bcmring: semaphore cleanup printk: Make console_sem a semaphore not a pseudo mutex drivers/macintosh/adb: Do not claim that the semaphore is a mutex parport: Semaphore cleanup irda: Semaphore cleanup net: Wan/cosa.c: Convert "mutex" to semaphore net: Ppp_async: semaphore cleanup hamradio: Mkiss: semaphore cleanup hamradio: 6pack: semaphore cleanup net: 3c527: semaphore cleanup input: Serio/hp_sdc: semaphore cleanup input: Serio/hil_mlc: semaphore cleanup input: Misc/hp_sdc_rtc: semaphore cleanup lockup_detector: Make callback function static lockup detector: Fix grammar by adding a missing "to" in the comments lockdep: Remove __debug_show_held_locks
2010-10-21security: remove unused parameter from security_task_setscheduler()KOSAKI Motohiro
All security modules shouldn't change sched_param parameter of security_task_setscheduler(). This is not only meaningless, but also make a harmful result if caller pass a static variable. This patch remove policy and sched_param parameter from security_task_setscheduler() becuase none of security module is using it. Cc: James Morris <jmorris@namei.org> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-10-20Merge branch 'linus' into irq/coreIngo Molnar
Merge reason: update to almost-final-.36 Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-19Merge branch 'devel-stable' into develRussell King
2010-10-19Merge branch 'tip/perf/core' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
2010-10-19tracing: Fix compile issue for trace_sched_wakeup.cSteven Rostedt
The function start_func_tracer() was incorrectly added in the #ifdef CONFIG_FUNCTION_TRACER condition, but is still used even when function tracing is not enabled. The calls to register_ftrace_function() and register_ftrace_graph() become nops (and their arguments are even ignored), thus there is no reason to hide start_func_tracer() when function tracing is not enabled. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-19futex: Fix errors in nested key ref-countingDarren Hart
futex_wait() is leaking key references due to futex_wait_setup() acquiring an additional reference via the queue_lock() routine. The nested key ref-counting has been masking bugs and complicating code analysis. queue_lock() is only called with a previously ref-counted key, so remove the additional ref-counting from the queue_(un)lock() functions. Also futex_wait_requeue_pi() drops one key reference too many in unqueue_me_pi(). Remove the key reference handling from unqueue_me_pi(). This was paired with a queue_lock() in futex_lock_pi(), so the count remains unchanged. Document remaining nested key ref-counting sites. Signed-off-by: Darren Hart <dvhart@linux.intel.com> Reported-and-tested-by: Matthieu Fertré<matthieu.fertre@kerlabs.com> Reported-by: Louis Rilling<louis.rilling@kerlabs.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: John Kacur <jkacur@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <4CBB17A8.70401@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2010-10-19blktrace: remove the big kernel lockArnd Bergmann
According to Jens, this code does not need the BKL at all, it is sufficiently serialized by bd_mutex. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Jens Axboe <jaxboe@fusionio.com> Cc: Steven Rostedt <rostedt@goodmis.org>
2010-10-19rtmutex-tester: make it build without BKLArnd Bergmann
The big kernel lock is going away, so make sure that if it is disabled by Kconfig, we do not try to validate it, which would result in compile errors. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org>
2010-10-18Merge branches 'at91', 'dcache', 'ftrace', 'hwbpt', 'misc', 'mmci', 's3c', ↵Russell King
'st-ux' and 'unwind' into devel
2010-10-18sched: Export account_system_vtime()Ingo Molnar
KVM uses it for example: ERROR: "account_system_vtime" [arch/x86/kvm/kvm.ko] undefined! Cc: Venkatesh Pallipadi <venki@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-3-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Call tick_check_idle before __irq_enterVenkatesh Pallipadi
When CPU is idle and on first interrupt, irq_enter calls tick_check_idle() to notify interruption from idle. But, there is a problem if this call is done after __irq_enter, as all routines in __irq_enter may find stale time due to yet to be done tick_check_idle. Specifically, trace calls in __irq_enter when they use global clock and also account_system_vtime change in this patch as it wants to use sched_clock_cpu() to do proper irq timing. But, tick_check_idle was moved after __irq_enter intentionally to prevent problem of unneeded ksoftirqd wakeups by the commit ee5f80a: irq: call __irq_enter() before calling the tick_idle_check Impact: avoid spurious ksoftirqd wakeups Moving tick_check_idle() before __irq_enter and wrapping it with local_bh_enable/disable would solve both the problems. Fixed-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-9-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Remove irq time from available CPU powerVenkatesh Pallipadi
The idea was suggested by Peter Zijlstra here: http://marc.info/?l=linux-kernel&m=127476934517534&w=2 irq time is technically not available to the tasks running on the CPU. This patch removes irq time from CPU power piggybacking on sched_rt_avg_update(). Tested this by keeping CPU X busy with a network intensive task having 75% oa a single CPU irq processing (hard+soft) on a 4-way system. And start seven cycle soakers on the system. Without this change, there will be two tasks on each CPU. With this change, there is a single task on irq busy CPU X and remaining 7 tasks are spread around among other 3 CPUs. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-8-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Do not account irq time to current taskVenkatesh Pallipadi
Scheduler accounts both softirq and interrupt processing times to the currently running task. This means, if the interrupt processing was for some other task in the system, then the current task ends up being penalized as it gets shorter runtime than otherwise. Change sched task accounting to acoount only actual task time from currently running task. Now update_curr(), modifies the delta_exec to depend on rq->clock_task. Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats for later. This change will impact scheduling behavior in interrupt heavy conditions. Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2 spending 75%+ of its time in irq processing. CPU 3 spending around 35% time running nc task. Now, if I run another CPU intensive task on CPU 2, without this change /proc/<pid>/schedstat shows 100% of time accounted to this task. With this change, it rightly shows less than 25% accounted to this task as remaining time is actually spent on irq processing. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq timeVenkatesh Pallipadi
s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Add a PF flag for ksoftirqd identificationVenkatesh Pallipadi
To account softirq time cleanly in scheduler, we need to identify whether softirq is invoked in ksoftirqd context or softirq at hardirq tail context. Add PF_KSOFTIRQD for that purpose. As all PF flag bits are currently taken, create space by moving one of the infrequently used bits (PF_THREAD_BOUND) down in task_struct to be along with some other state fields. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-4-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Fix softirq time accountingVenkatesh Pallipadi
Peter Zijlstra found a bug in the way softirq time is accounted in VIRT_CPU_ACCOUNTING on this thread: http://lkml.indiana.edu/hypermail//linux/kernel/1009.2/01366.html The problem is, softirq processing uses local_bh_disable internally. There is no way, later in the flow, to differentiate between whether softirq is being processed or is it just that bh has been disabled. So, a hardirq when bh is disabled results in time being wrongly accounted as softirq. Looking at the code a bit more, the problem exists in !VIRT_CPU_ACCOUNTING as well. As account_system_time() in normal tick based accouting also uses softirq_count, which will be set even when not in softirq with bh disabled. Peter also suggested solution of using 2*SOFTIRQ_OFFSET as irq count for local_bh_{disable,enable} and using just SOFTIRQ_OFFSET while softirq processing. The patch below does that and adds API in_serving_softirq() which returns whether we are currently processing softirq or not. Also changes one of the usages of softirq_count in net/sched/cls_cgroup.c to in_serving_softirq. Looks like many usages of in_softirq really want in_serving_softirq. Those changes can be made individually on a case by case basis. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-2-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Drop group_capacity to 1 only if local group has extra capacityNikhil Rao
When SD_PREFER_SIBLING is set on a sched domain, drop group_capacity to 1 only if the local group has extra capacity. The extra check prevents the case where you always pull from the heaviest group when it is already under-utilized (possible with a large weight task outweighs the tasks on the system). For example, consider a 16-cpu quad-core quad-socket machine with MC and NUMA scheduling domains. Let's say we spawn 15 nice0 tasks and one nice-15 task, and each task is running on one core. In this case, we observe the following events when balancing at the NUMA domain: - find_busiest_group() will always pick the sched group containing the niced task to be the busiest group. - find_busiest_queue() will then always pick one of the cpus running the nice0 task (never picks the cpu with the nice -15 task since weighted_cpuload > imbalance). - The load balancer fails to migrate the task since it is the running task and increments sd->nr_balance_failed. - It repeats the above steps a few more times until sd->nr_balance_failed > 5, at which point it kicks off the active load balancer, wakes up the migration thread and kicks the nice 0 task off the cpu. The load balancer doesn't stop until we kick out all nice 0 tasks from the sched group, leaving you with 3 idle cpus and one cpu running the nice -15 task. When balancing at the NUMA domain, we drop sgs.group_capacity to 1 if the child domain (in this case MC) has SD_PREFER_SIBLING set. Subsequent load checks are not relevant because the niced task has a very large weight. In this patch, we add an extra condition to the "if(prefer_sibling)" check in update_sd_lb_stats(). We drop the capacity of a group only if the local group has extra capacity, ie. nr_running < group_capacity. This patch preserves the original intent of the prefer_siblings check (to spread tasks across the system in low utilization scenarios) and fixes the case above. It helps in the following ways: - In low utilization cases (where nr_tasks << nr_cpus), we still drop group_capacity down to 1 if we prefer siblings. - On very busy systems (where nr_tasks >> nr_cpus), sgs.nr_running will most likely be > sgs.group_capacity. - When balancing large weight tasks, if the local group does not have extra capacity, we do not pick the group with the niced task as the busiest group. This prevents failed balances, active migration and the under-utilization described above. Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1287173550-30365-5-git-send-email-ncrao@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Force balancing on newidle balance if local group has capacityNikhil Rao
This patch forces a load balance on a newly idle cpu when the local group has extra capacity and the busiest group does not have any. It improves system utilization when balancing tasks with a large weight differential. Under certain situations, such as a niced down task (i.e. nice = -15) in the presence of nr_cpus NICE0 tasks, the niced task lands on a sched group and kicks away other tasks because of its large weight. This leads to sub-optimal utilization of the machine. Even though the sched group has capacity, it does not pull tasks because sds.this_load >> sds.max_load, and f_b_g() returns NULL. With this patch, if the local group has extra capacity, we shortcut the checks in f_b_g() and try to pull a task over. A sched group has extra capacity if the group capacity is greater than the number of running tasks in that group. Thanks to Mike Galbraith for discussions leading to this patch and for the insight to reuse SD_NEWIDLE_BALANCE. Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1287173550-30365-4-git-send-email-ncrao@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Set group_imb only a task can be pulled from the busiest cpuNikhil Rao
When cycling through sched groups to determine the busiest group, set group_imb only if the busiest cpu has more than 1 runnable task. This patch fixes the case where two cpus in a group have one runnable task each, but there is a large weight differential between these two tasks. The load balancer is unable to migrate any task from this group, and hence do not consider this group to be imbalanced. Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286996978-7007-3-git-send-email-ncrao@google.com> [ small code readability edits ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Do not consider SCHED_IDLE tasks to be cache hotNikhil Rao
This patch adds a check in task_hot to return if the task has SCHED_IDLE policy. SCHED_IDLE tasks have very low weight, and when run with regular workloads, are typically scheduled many milliseconds apart. There is no need to consider these tasks hot for load balancing. Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1287173550-30365-2-git-send-email-ncrao@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18perf: Optimize sw eventsPeter Zijlstra
Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18perf: Use jump_labels to optimize the scheduler hooksPeter Zijlstra
Trades a call + conditional + ret for an unconditional jmp. Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101014203625.501657727@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18jump_label: Use more consistent namingPeter Zijlstra
Now that there's still only a few users around, rename things to make them more consistent. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101014203625.448565169@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18perf, hw_breakpoint: Fix crash in hw_breakpoint creationPeter Zijlstra
hw_breakpoint creation needs to account stuff per-task to ensure there is always sufficient hardware resources to back these things due to ptrace. With the perf per pmu context changes the event initialization no longer has access to the event context, for the simple reason that we need to first find the pmu (result of initialization) before we can find the context. This makes hw_breakpoints unhappy, because it can no longer do per task accounting, cure this by frobbing a task pointer in the event::hw bits for now... Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20101014203625.391543667@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18perf: Find task before event allocPeter Zijlstra
So that we can pass the task pointer to the event allocation, so that we can use task associated data during event initialization. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101014203625.340789919@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18perf: Fix task refcount bugsPeter Zijlstra
Currently it looks like find_lively_task_by_vpid() takes a task ref and relies on find_get_context() to drop it. The problem is that perf_event_create_kernel_counter() shouldn't be dropping task refs. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Matt Helsley <matthltc@us.ibm.com> LKML-Reference: <20101014203625.278436085@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18perf: Fix group movingPeter Zijlstra
Matt found we trigger the WARN_ON_ONCE() in perf_group_attach() when we take the move_group path in perf_event_open(). Since we cannot de-construct the group (we rely on it to move the events), we have to simply ignore the double attach. The group state is context invariant and doesn't need changing. Reported-by: Matt Fleming <matt@console-pimps.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1287135757.29097.1368.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18irq_work: Add generic hardirq context callbacksPeter Zijlstra
Provide a mechanism that allows running code in IRQ context. It is most useful for NMI code that needs to interact with the rest of the system -- like wakeup a task to drain buffers. Perf currently has such a mechanism, so extract that and provide it as a generic feature, independent of perf so that others may also benefit. The IRQ context callback is generated through self-IPIs where possible, or on architectures like powerpc the decrementer (the built-in timer facility) is set to generate an interrupt immediately. Architectures that don't have anything like this get to do with a callback from the timer tick. These architectures can call irq_work_run() at the tail of any IRQ handlers that might enqueue such work (like the perf IRQ handler) to avoid undue latencies in processing the work. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [ various fixes ] Signed-off-by: Huang Ying <ying.huang@intel.com> LKML-Reference: <1287036094.7768.291.camel@yhuang-dev> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18perf_events: Fix transaction recovery in group_sched_in()Stephane Eranian
The group_sched_in() function uses a transactional approach to schedule a group of events. In a group, either all events can be scheduled or none are. To schedule each event in, the function calls event_sched_in(). In case of error, event_sched_out() is called on each event in the group. The problem is that event_sched_out() does not completely cancel the effects of event_sched_in(). Furthermore event_sched_out() changes the state of the event as if it had run which is not true is this particular case. Those inconsistencies impact time tracking fields and may lead to events in a group not all reporting the same time_enabled and time_running values. This is demonstrated with the example below: $ task -eunhalted_core_cycles,baclears,baclears -e unhalted_core_cycles,baclears,baclears sleep 5 1946101 unhalted_core_cycles (32.85% scaling, ena=829181, run=556827) 11423 baclears (32.85% scaling, ena=829181, run=556827) 7671 baclears (0.00% scaling, ena=556827, run=556827) 2250443 unhalted_core_cycles (57.83% scaling, ena=962822, run=405995) 11705 baclears (57.83% scaling, ena=962822, run=405995) 11705 baclears (57.83% scaling, ena=962822, run=405995) Notice that in the first group, the last baclears event does not report the same timings as its siblings. This issue comes from the fact that tstamp_stopped is updated by event_sched_out() as if the event had actually run. To solve the issue, we must ensure that, in case of error, there is no change in the event state whatsoever. That means timings must remain as they were when entering group_sched_in(). To do this we defer updating tstamp_running until we know the transaction succeeded. Therefore, we have split event_sched_in() in two parts separating the update to tstamp_running. Similarly, in case of error, we do not want to update tstamp_stopped. Therefore, we have split event_sched_out() in two parts separating the update to tstamp_stopped. With this patch, we now get the following output: $ task -eunhalted_core_cycles,baclears,baclears -e unhalted_core_cycles,baclears,baclears sleep 5 2492050 unhalted_core_cycles (71.75% scaling, ena=1093330, run=308841) 11243 baclears (71.75% scaling, ena=1093330, run=308841) 11243 baclears (71.75% scaling, ena=1093330, run=308841) 1852746 unhalted_core_cycles (0.00% scaling, ena=784489, run=784489) 9253 baclears (0.00% scaling, ena=784489, run=784489) 9253 baclears (0.00% scaling, ena=784489, run=784489) Note that the uneven timing between groups is a side effect of the process spending most of its time sleeping, i.e., not enough event rotations (but that's a separate issue). Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4cb86b4c.41e9d80a.44e9.3e19@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18perf_events: Fix bogus context time trackingStephane Eranian
You can only call update_context_time() when the context is active, i.e., the thread it is attached to is still running. However, perf_event_read() can be called even when the context is inactive, e.g., user read() the counters. The call to update_context_time() must be conditioned on the status of the context, otherwise, bogus time_enabled, time_running may be returned. Here is an example on AMD64. The task program is an example from libpfm4. The -p prints deltas every 1s. $ task -p -e cpu_clk_unhalted sleep 5 2,266,610 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982) 0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982) 0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982) 0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982) 0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982) 5,242,358,071 cpu_clk_unhalted (99.95% scaling, ena=5,000,359,984, run=2,319,270) Whereas if you don't read deltas, e.g., no call to perf_event_read() until the process terminates: $ task -e cpu_clk_unhalted sleep 5 2,497,783 cpu_clk_unhalted (0.00% scaling, ena=2,376,899, run=2,376,899) Notice that time_enable, time_running are bogus in the first example causing bogus scaling. This patch fixes the problem, by conditionally calling update_context_time() in perf_event_read(). Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org LKML-Reference: <4cb856dc.51edd80a.5ae0.38fb@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18lockdep: Check the depth of subclassHitoshi Mitake
Current look_up_lock_class() doesn't check the parameter "subclass". This rarely rises problems because the main caller of this function, register_lock_class(), checks it. But register_lock_class() is not the only function which calls look_up_lock_class(). lock_set_class() and its callees also call it. And lock_set_class() doesn't check this parameter. This will rise problems when the the value of subclass is larger than MAX_LOCKDEP_SUBCLASSES. Because the address (used as the key of class) caliculated with too large subclass has a probability to point another key in different lock_class_key. Of course this problem depends on the memory layout and occurs with really low probability. Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> Cc: Dmitry Torokhov <dtor@mail.ru> Cc: Vojtech Pavlik <vojtech@ucw.cz> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286958626-986-1-git-send-email-mitake@dcl.info.waseda.ac.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18lockdep: Add improved subclass cachingHitoshi Mitake
Current lockdep_map only caches one class with subclass == 0, and looks up hash table of classes when subclass != 0. It seems that this has no problem because the case of subclass != 0 is rare. But locks of struct rq are acquired with subclass == 1 when task migration is executed. Task migration is high frequent event, so I modified lockdep to cache subclasses. I measured the score of perf bench sched messaging. This patch has slightly but certain (order of milli seconds or 10 milli seconds) effect when lots of tasks are running. I'll show the result in the tail of this description. NR_LOCKDEP_CACHING_CLASSES specifies how many classes can be cached in the instances of lockdep_map. I discussed with Peter Zijlstra in LinuxCon Japan about this approach and he taught me that caching every subclasses(8) is cleary waste of memory. So number of cached classes should be configurable. === Score comparison of benchmarks === # "min" means best score, and "max" means worst score for i in `seq 1 10`; do ./perf bench -f simple sched messaging; done before: min: 0.565000, max: 0.583000, avg: 0.572500 after: min: 0.559000, max: 0.568000, avg: 0.563300 # with more processes for i in `seq 1 10`; do ./perf bench -f simple sched messaging -g 40; done before: min: 2.274000, max: 2.298000, avg: 2.286300 after: min: 2.242000, max: 2.270000, avg: 2.259700 Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286269311-28336-2-git-send-email-mitake@dcl.info.waseda.ac.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18Merge branch 'linus' into core/lockingIngo Molnar
Merge reason: Update to almost-final-.36 Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Drop all load weight manipulation for RT tasksLinus Walleij
Load weights are for the CFS, they do not belong in the RT task. This makes all RT scheduling classes leave the CFS weights alone. This fixes a real bug as well: I noticed the following phonomena: a process elevated to SCHED_RR forks with SCHED_RESET_ON_FORK set, and the child is indeed SCHED_OTHER, and the niceval is indeed reset to 0. However the weight inserted by set_load_weight() remains at 0, giving the task insignificat priority. With this fix, the weight is reset to what the task had before being elevated to SCHED_RR/SCHED_FIFO. Cc: Lennart Poettering <lennart@poettering.net> Cc: stable@kernel.org Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286807811-10568-1-git-send-email-linus.walleij@stericsson.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Create special class for stop/migrate workPeter Zijlstra
In order to separate the stop/migrate work thread from the SCHED_FIFO implementation, create a special class for it that is of higher priority than SCHED_FIFO itself. This currently solves a problem where cpu-hotplug consumes so much cpu-time that the SCHED_FIFO class gets throttled, but has the bandwidth replenishment timer pending on the now dead cpu. It is also required for when we add the planned deadline scheduling class above SCHED_FIFO, as the stop/migrate thread still needs to transcent those tasks. Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1285165776.2275.1022.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>