summaryrefslogtreecommitdiffstats
path: root/arch/x86
AgeCommit message (Collapse)Author
2014-02-13x86, smap: smap_violation() is bogus if CONFIG_X86_SMAP is offH. Peter Anvin
If CONFIG_X86_SMAP is disabled, smap_violation() tests for conditions which are incorrect (as the AC flag doesn't matter), causing spurious faults. The dynamic disabling of SMAP (nosmap on the command line) is fine because it disables X86_FEATURE_SMAP, therefore causing the static_cpu_has() to return false. Found by Fengguang Wu's test system. [ v3: move all predicates into smap_violation() ] [ v2: use IS_ENABLED() instead of #ifdef ] Reported-by: Fengguang Wu <fengguang.wu@intel.com> Link: http://lkml.kernel.org/r/20140213124550.GA30497@localhost Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org> # v3.7+
2014-02-13x86, smap: Don't enable SMAP if CONFIG_X86_SMAP is disabledH. Peter Anvin
If SMAP support is not compiled into the kernel, don't enable SMAP in CR4 -- in fact, we should clear it, because the kernel doesn't contain the proper STAC/CLAC instructions for SMAP support. Found by Fengguang Wu's test system. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Link: http://lkml.kernel.org/r/20140213124550.GA30497@localhost Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org> # v3.7+
2014-02-09x86: Use preempt_disable_notrace() in cycles_2_ns()Steven Rostedt
When debug preempt is enabled, preempt_disable() can be traced by function and function graph tracing. There's a place in the function graph tracer that calls trace_clock() which eventually calls cycles_2_ns() outside of the recursion protection. When cycles_2_ns() calls preempt_disable() it gets traced and the graph tracer will go into a recursive loop causing a crash or worse, a triple fault. Simple fix is to use preempt_disable_notrace() in cycles_2_ns, which makes sense because the preempt_disable() tracing may use that code too, and it tracing it, even with recursion protection is rather pointless. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140204141315.2a968a72@gandalf.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-08Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Peter Anvin: "Quite a varied little collection of fixes. Most of them are relatively small or isolated; the biggest one is Mel Gorman's fixes for TLB range flushing. A couple of AMD-related fixes (including not crashing when given an invalid microcode image) and fix a crash when compiled with gcov" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, microcode, AMD: Unify valid container checks x86, hweight: Fix BUG when booting with CONFIG_GCOV_PROFILE_ALL=y x86/efi: Allow mapping BGRT on x86-32 x86: Fix the initialization of physnode_map x86, cpu hotplug: Fix stack frame warning in check_irq_vectors_for_cpu_disable() x86/intel/mid: Fix X86_INTEL_MID dependencies arch/x86/mm/srat: Skip NUMA_NO_NODE while parsing SLIT mm, x86: Revisit tlb_flushall_shift tuning for page flushes except on IvyBridge x86: mm: change tlb_flushall_shift for IvyBridge x86/mm: Eliminate redundant page table walk during TLB range flushing x86/mm: Clean up inconsistencies when flushing TLB ranges mm, x86: Account for TLB flushes only when debugging x86/AMD/NB: Fix amd_set_subcaches() parameter type x86/quirks: Add workaround for AMD F16h Erratum792 x86, doc, kconfig: Fix dud URL for Microcode data
2014-02-07Merge tag 'efi-urgent' into x86/urgentH. Peter Anvin
* Avoid WARN_ON() when mapping BGRT on Baytrail (EFI 32-bit). Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-02-06arch/x86/mm/numa.c: fix array index overflow when synchronizing nid to ↵Tang Chen
memblock.reserved. The following path will cause array out of bound. memblock_add_region() will always set nid in memblock.reserved to MAX_NUMNODES. In numa_register_memblks(), after we set all nid to correct valus in memblock.reserved, we called setup_node_data(), and used memblock_alloc_nid() to allocate memory, with nid set to MAX_NUMNODES. The nodemask_t type can be seen as a bit array. And the index is 0 ~ MAX_NUMNODES-1. After that, when we call node_set() in numa_clear_kernel_node_hotplug(), the nodemask_t got an index of value MAX_NUMNODES, which is out of [0 ~ MAX_NUMNODES-1]. See below: numa_init() |---> numa_register_memblks() | |---> memblock_set_node(memory) set correct nid in memblock.memory | |---> memblock_set_node(reserved) set correct nid in memblock.reserved | |...... | |---> setup_node_data() | |---> memblock_alloc_nid() here, nid is set to MAX_NUMNODES (1024) |...... |---> numa_clear_kernel_node_hotplug() |---> node_set() here, we have an index 1024, and overflowed This patch moves nid setting to numa_clear_kernel_node_hotplug() to fix this problem. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Tested-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Reported-by: Dave Jones <davej@redhat.com> Cc: David Rientjes <rientjes@google.com> Tested-by: Dave Jones <davej@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-06arch/x86/mm/numa.c: initialize numa_kernel_nodes in ↵Tang Chen
numa_clear_kernel_node_hotplug() On-stack variable numa_kernel_nodes in numa_clear_kernel_node_hotplug() was not initialized. So we need to initialize it. [akpm@linux-foundation.org: use NODE_MASK_NONE, per David] Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Tested-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Reported-by: Dave Jones <davej@redhat.com> Reported-by: David Rientjes <rientjes@google.com> Tested-by: Dave Jones <davej@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-06x86, microcode, AMD: Unify valid container checksBorislav Petkov
For additional coverage, BorisO and friends unknowlingly did swap AMD microcode with Intel microcode blobs in order to see what happens. What did happen on 32-bit was [ 5.722656] BUG: unable to handle kernel paging request at be3a6008 [ 5.722693] IP: [<c106d6b4>] load_microcode_amd+0x24/0x3f0 [ 5.722716] *pdpt = 0000000000000000 *pde = 0000000000000000 because there was a valid initrd there but without valid microcode in it and the container check happened *after* the relocated ramdisk handling on 32-bit, which was clearly wrong. While at it, take care of the ramdisk relocation on both 32- and 64-bit as it is done on both. Also, comment what we're doing because this code is a bit tricky. Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1391460104-7261-1-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-02-05Merge tag 'stable/for-linus-3.14-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen fixes from Konrad Rzeszutek Wilk: "Bug-fixes: - Revert "xen/grant-table: Avoid m2p_override during mapping" as it broke Xen ARM build. - Fix CR4 not being set on AP processors in Xen PVH mode" * tag 'stable/for-linus-3.14-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/pvh: set CR4 flags for APs Revert "xen/grant-table: Avoid m2p_override during mapping"
2014-02-05x86/efi: Allow mapping BGRT on x86-32Matt Fleming
CONFIG_X86_32 doesn't map the boot services regions into the EFI memory map (see commit 700870119f49 ("x86, efi: Don't map Boot Services on i386")), and so efi_lookup_mapped_addr() will fail to return a valid address. Executing the ioremap() path in efi_bgrt_init() causes the following warning on x86-32 because we're trying to ioremap() RAM, WARNING: CPU: 0 PID: 0 at arch/x86/mm/ioremap.c:102 __ioremap_caller+0x2ad/0x2c0() Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.13.0-0.rc5.git0.1.2.fc21.i686 #1 Hardware name: DellInc. Venue 8 Pro 5830/09RP78, BIOS A02 10/17/2013 00000000 00000000 c0c0df08 c09a5196 00000000 c0c0df38 c0448c1e c0b41310 00000000 00000000 c0b37bc1 00000066 c043bbfd c043bbfd 00e7dfe0 00073eff 00073eff c0c0df48 c0448ce2 00000009 00000000 c0c0df9c c043bbfd 00078d88 Call Trace: [<c09a5196>] dump_stack+0x41/0x52 [<c0448c1e>] warn_slowpath_common+0x7e/0xa0 [<c043bbfd>] ? __ioremap_caller+0x2ad/0x2c0 [<c043bbfd>] ? __ioremap_caller+0x2ad/0x2c0 [<c0448ce2>] warn_slowpath_null+0x22/0x30 [<c043bbfd>] __ioremap_caller+0x2ad/0x2c0 [<c0718f92>] ? acpi_tb_verify_table+0x1c/0x43 [<c0719c78>] ? acpi_get_table_with_size+0x63/0xb5 [<c087cd5e>] ? efi_lookup_mapped_addr+0xe/0xf0 [<c043bc2b>] ioremap_nocache+0x1b/0x20 [<c0cb01c8>] ? efi_bgrt_init+0x83/0x10c [<c0cb01c8>] efi_bgrt_init+0x83/0x10c [<c0cafd82>] efi_late_init+0x8/0xa [<c0c9bab2>] start_kernel+0x3ae/0x3c3 [<c0c9b53b>] ? repair_env_string+0x51/0x51 [<c0c9b378>] i386_start_kernel+0x12e/0x131 Switch to using early_memremap(), which won't trigger this warning, and has the added benefit of more accurately conveying what we're trying to do - map a chunk of memory. This patch addresses the following bug report, https://bugzilla.kernel.org/show_bug.cgi?id=67911 Reported-by: Adam Williamson <awilliam@redhat.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-02-05x86: Disable CONFIG_X86_DECODER_SELFTEST in allmod/allyesconfigsIngo Molnar
It can take some time to validate the image, make sure {allyes|allmod}config doesn't enable it. I'd say randconfig will cover it often enough, and the failure is also borderline build coverage related: you cannot really make the decoder test fail via source level changes, only with changes in the build environment, so I agree with Andi that we can disable this one too. Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Paul Gortmaker paul.gortmaker@windriver.com> Suggested-and-acked-by: Andi Kleen andi@firstfloor.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-03xen/pvh: set CR4 flags for APsMukesh Rathor
During bootup in the 'probe_page_size_mask' these CR4 flags are set in there. But for AP processors they are not set as we do not use 'secondary_startup_64' which the baremetal kernels uses. Instead do it in this function which we use in Xen PVH during our startup for AP processors. As such fix it up to make sure we have that flag set. Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-02-03Revert "xen/grant-table: Avoid m2p_override during mapping"Konrad Rzeszutek Wilk
This reverts commit 08ece5bb2312b4510b161a6ef6682f37f4eac8a1. As it breaks ARM builds and needs more attention on the ARM side. Acked-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-02-01x86: Fix the initialization of physnode_mapPetr Tesarik
With DISCONTIGMEM, the mapping between a pfn and its owning node is initialized using data provided by the BIOS. However, the initialization may fail if the extents are not aligned to section boundary (64M). The symptom of this bug is an early boot failure in pfn_to_page(), as it tries to access NODE_DATA(__nid) using index from an unitialized element of the physnode_map[] array. While the bug is always present, it is more likely to be hit in kdump kernels on large machines, because: 1. The memory map for a kdump kernel is specified as exactmap, and exactmap is more likely to be unaligned. 2. Large reservations are more likely to span across a 64M boundary. [ hpa: fixed incorrect use of "pfn" instead of "start" ] Signed-off-by: Petr Tesarik <ptesarik@suse.cz> Link: http://lkml.kernel.org/r/20140201133019.32e56f86@hananiah.suse.cz Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-01-31Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core debug changes from Ingo Molnar: "This contains mostly kernel debugging related updates: - make hung_task detection more configurable to distros - add final bits for x86 UV NMI debugging, with related KGDB changes - update the mailing-list of MAINTAINERS entries I'm involved with" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hung_task: Display every hung task warning sysctl: Add neg_one as a standard constraint x86/uv/nmi, kgdb/kdb: Fix UV NMI handler when KDB not configured x86/uv/nmi: Fix Sparse warnings kgdb/kdb: Fix no KDB config problem MAINTAINERS: Restore "L: linux-kernel@vger.kernel.org" entries
2014-01-31Merge tag 'stable/for-linus-3.14-rc0-late-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen bugfixes from Konrad Rzeszutek Wilk: "Bug-fixes for the new features that were added during this cycle. There are also two fixes for long-standing issues for which we have a solution: grant-table operations extra work that was not needed causing performance issues and the self balloon code was too aggressive causing OOMs. Details: - Xen ARM couldn't use the new FIFO events - Xen ARM couldn't use the SWIOTLB if compiled as 32-bit with 64-bit PCIe devices. - Grant table were doing needless M2P operations. - Ratchet down the self-balloon code so it won't OOM. - Fix misplaced kfree in Xen PVH error code paths" * tag 'stable/for-linus-3.14-rc0-late-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/pvh: Fix misplaced kfree from xlated_setup_gnttab_pages drivers: xen: deaggressive selfballoon driver xen/grant-table: Avoid m2p_override during mapping xen/gnttab: Use phys_addr_t to describe the grant frame base address xen: swiotlb: handle sizeof(dma_addr_t) != sizeof(phys_addr_t) arm/xen: Initialize event channels earlier
2014-01-31Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull more KVM updates from Paolo Bonzini: "Second batch of KVM updates. Some minor x86 fixes, two s390 guest features that need some handling in the host, and all the PPC changes. The PPC changes include support for little-endian guests and enablement for new POWER8 features" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (45 commits) x86, kvm: correctly access the KVM_CPUID_FEATURES leaf at 0x40000101 x86, kvm: cache the base of the KVM cpuid leaves kvm: x86: move KVM_CAP_HYPERV_TIME outside #ifdef KVM: PPC: Book3S PR: Cope with doorbell interrupts KVM: PPC: Book3S HV: Add software abort codes for transactional memory KVM: PPC: Book3S HV: Add new state for transactional memory powerpc/Kconfig: Make TM select VSX and VMX KVM: PPC: Book3S HV: Basic little-endian guest support KVM: PPC: Book3S HV: Add support for DABRX register on POWER7 KVM: PPC: Book3S HV: Prepare for host using hypervisor doorbells KVM: PPC: Book3S HV: Handle new LPCR bits on POWER8 KVM: PPC: Book3S HV: Handle guest using doorbells for IPIs KVM: PPC: Book3S HV: Consolidate code that checks reason for wake from nap KVM: PPC: Book3S HV: Implement architecture compatibility modes for POWER8 KVM: PPC: Book3S HV: Add handler for HV facility unavailable KVM: PPC: Book3S HV: Flush the correct number of TLB sets on POWER8 KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs KVM: PPC: Book3S HV: Align physical and virtual CPU thread numbers KVM: PPC: Book3S HV: Don't set DABR on POWER8 kvm/ppc: IRQ disabling cleanup ...
2014-01-31xen/pvh: Fix misplaced kfree from xlated_setup_gnttab_pagesDave Jones
Passing a freed 'pages' to free_xenballooned_pages will end badly on kernels with slub debug enabled. This looks out of place between the rc assign and the check, but we do want to kfree pages regardless of which path we take. Signed-off-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-31xen/grant-table: Avoid m2p_override during mappingZoltan Kiss
The grant mapping API does m2p_override unnecessarily: only gntdev needs it, for blkback and future netback patches it just cause a lock contention, as those pages never go to userspace. Therefore this series does the following: - the original functions were renamed to __gnttab_[un]map_refs, with a new parameter m2p_override - based on m2p_override either they follow the original behaviour, or just set the private flag and call set_phys_to_machine - gnttab_[un]map_refs are now a wrapper to call __gnttab_[un]map_refs with m2p_override false - a new function gnttab_[un]map_refs_userspace provides the old behaviour It also removes a stray space from page.h and change ret to 0 if XENFEAT_auto_translated_physmap, as that is the only possible return value there. v2: - move the storing of the old mfn in page->index to gnttab_map_refs - move the function header update to a separate patch v3: - a new approach to retain old behaviour where it needed - squash the patches into one v4: - move out the common bits from m2p* functions, and pass pfn/mfn as parameter - clear page->private before doing anything with the page, so m2p_find_override won't race with this v5: - change return value handling in __gnttab_[un]map_refs - remove a stray space in page.h - add detail why ret = 0 now at some places v6: - don't pass pfn to m2p* functions, just get it locally Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Suggested-by: David Vrabel <david.vrabel@citrix.com> Acked-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-30Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge misc fixes from Andrew Morton: "A few hotfixes and various leftovers which were awaiting other merges. Mainly movement of zram into mm/" * emailed patches fron Andrew Morton <akpm@linux-foundation.org>: (25 commits) memcg: fix mutex not unlocked on memcg_create_kmem_cache fail path Documentation/filesystems/vfs.txt: update file_operations documentation mm, oom: base root bonus on current usage mm: don't lose the SOFT_DIRTY flag on mprotect mm/slub.c: fix page->_count corruption (again) mm/mempolicy.c: fix mempolicy printing in numa_maps zram: remove zram->lock in read path and change it with mutex zram: remove workqueue for freeing removed pending slot zram: introduce zram->tb_lock zram: use atomic operation for stat zram: remove unnecessary free zram: delay pending free request in read path zram: fix race between reset and flushing pending work zsmalloc: add maintainers zram: add zram maintainers zsmalloc: add copyright zram: add copyright zram: remove old private project comment zram: promote zram from staging zsmalloc: move it under mm ...
2014-01-30Merge branch 'x86-asmlinkage-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asmlinkage (LTO) changes from Peter Anvin: "This patchset adds more infrastructure for link time optimization (LTO). This patchset was pulled into my tree late because of a miscommunication (part of the patchset was picked up by other maintainers). However, the patchset is strictly build-related and seems to be okay in testing" * 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, asmlinkage, xen: Fix type of NMI x86, asmlinkage, xen, kvm: Make {xen,kvm}_lock_spinning global and visible x86: Use inline assembler instead of global register variable to get sp x86, asmlinkage, paravirt: Make paravirt thunks global x86, asmlinkage, paravirt: Don't rely on local assembler labels x86, asmlinkage, lguest: Fix C functions used by inline assembler
2014-01-30Merge branch 'x86-build-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build bits from Peter Anvin: "Various build-related minor bits. Most of this is work by David Woodhouse to be able to compile the early boot code with clang/llvm; we have also managed to push an actual -m16 option into gcc 4.9 so this makes us use that option if available instead of hacking it. The balance is a patch from Michael Davidson to the relocs program to help manual debugging. None of these should change the actual compiled binary with currently released compilers" * 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, build: Build 16-bit code with -m16 where possible x86, boot: Fix word-size assumptions in has_eflag() inline asm x86, boot: Use __attribute__((used)) to ensure videocard structs are emitted x86: Remove duplication of 16-bit CFLAGS x86, relocs: Add manual debug mode
2014-01-30Merge branch 'drop-time' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull __TIME__/__DATE__ removal from Michal Marek: "This series by Josh finishes the removal of __DATE__ and __TIME__ from the kernel. The last patch adds -Werror=date-time to KBUILD_CFLAGS to stop these from reappearing. Part of the series went through Greg's trees during this merge window, which is why this pull request is not based on v3.13-rc1" * 'drop-time' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: Makefile: Build with -Werror=date-time if the compiler supports it x86: math-emu: Drop already-disabled print of build date net: wireless: brcm80211: Drop debug version with build date/time mtd: denali: Drop print of build date/time
2014-01-30mm: don't lose the SOFT_DIRTY flag on mprotectAndrey Vagin
The SOFT_DIRTY bit shows that the content of memory was changed after a defined point in the past. mprotect() doesn't change the content of memory, so it must not change the SOFT_DIRTY bit. This bug causes a malfunction: on the first iteration all pages are dumped. On other iterations only pages with the SOFT_DIRTY bit are dumped. So if the SOFT_DIRTY bit is cleared from a page by mistake, the page is not dumped and its content will be restored incorrectly. This patch does nothing with _PAGE_SWP_SOFT_DIRTY, becase pte_modify() is called only for present pages. Fixes commit 0f8975ec4db2 ("mm: soft-dirty bits for user memory changes tracking"). Signed-off-by: Andrey Vagin <avagin@openvz.org> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Borislav Petkov <bp@suse.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-30x86, cpu hotplug: Fix stack frame warning in check_irq_vectors_for_cpu_disable()Prarit Bhargava
Further discussion here: http://marc.info/?l=linux-kernel&m=139073901101034&w=2 kbuild, 0day kernel build service, outputs the warning: arch/x86/kernel/irq.c:333:1: warning: the frame size of 2056 bytes is larger than 2048 bytes [-Wframe-larger-than=] because check_irq_vectors_for_cpu_disable() allocates two cpumasks on the stack. Fix this by moving the two cpumasks to a global file context. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: David Rientjes <rientjes@google.com> Signed-off-by: Prarit Bhargava <prarit@redhat.com> Link: http://lkml.kernel.org/r/1390915331-27375-1-git-send-email-prarit@redhat.com Cc: Andi Kleen <ak@linux.intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Yang Zhang <yang.z.zhang@Intel.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Janet Morgan <janet.morgan@intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Ruiv Wang <ruiv.wang@gmail.com> Cc: Gong Chen <gong.chen@linux.intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-30x86, build: Build 16-bit code with -m16 where possibleDavid Woodhouse
Both clang 3.5 and GCC 4.9 will support this (as of r199754 and r207196 respectively). Both have been tested to produce booting kernels when the 16-bit code is built with -m16. (Modulo LLVM PR3997, at least.) [ hpa: folded test for -m16 into M16_CFLAGS ] Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Link: http://lkml.kernel.org/r/1390997807.20153.133.camel@i7.infradead.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-30x86, boot: Fix word-size assumptions in has_eflag() inline asmDavid Woodhouse
Commit dd78b97367bd575918204cc89107c1479d3fc1a7 ("x86, boot: Move CPU flags out of cpucheck") introduced ambiguous inline asm in the has_eflag() function. In 16-bit mode want the instruction to be 'pushfl', but we just say 'pushf' and hope the compiler does what we wanted. When building with 'clang -m16', it won't, because clang doesn't use the horrid '.code16gcc' hack that even 'gcc -m16' uses internally. Say what we mean and don't make the compiler make assumptions. [ hpa: ideally we would be able to use the gcc %zN construct here, but that is broken for 64-bit integers in gcc < 4.5. The code with plain "pushf/popf" is fine for 32- or 64-bit mode, but not for 16-bit mode; in 16-bit mode those are 16-bit instructions in .code16 mode, and 32-bit instructions in .code16gcc mode. ] Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Link: http://lkml.kernel.org/r/1391079628.26079.82.camel@shinybook.infradead.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29x86, asmlinkage, xen: Fix type of NMIAndi Kleen
LTO requires consistent types of symbols over all files. So "nmi" cannot be declared as a char [] here, need to use the correct function type. Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1382458079-24450-8-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29x86, asmlinkage, xen, kvm: Make {xen,kvm}_lock_spinning global and visibleAndi Kleen
These functions are called from inline assembler stubs, thus need to be global and visible. Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1382458079-24450-7-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29x86: Use inline assembler instead of global register variable to get spAndi Kleen
LTO in gcc 4.6/47. has trouble with global register variables. They were used to read the stack pointer. Use a simple inline assembler statement with a mov instead. This also helps LLVM/clang, which does not support global register variables. [ hpa: Ideally this should become a builtin in both gcc and clang. ] v2: More general asm constraint. Fix description (Jan Beulich) Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1382458079-24450-6-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29x86, asmlinkage, paravirt: Make paravirt thunks globalAndi Kleen
The paravirt thunks use a hack of using a static reference to a static function to reference that function from the top level statement. This assumes that gcc always generates static function names in a specific format, which is not necessarily true. Simply make these functions global and asmlinkage or __visible. This way the static __used variables are not needed and everything works. Functions with arguments are __visible to keep the register calling convention on 32bit. Changed in paravirt and in all users (Xen and vsmp) v2: Use __visible for functions with arguments Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Ido Yariv <ido@wizery.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1382458079-24450-5-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29x86, asmlinkage, paravirt: Don't rely on local assembler labelsAndi Kleen
The paravirt patching code assumes that it can reference a local assembler label between two different top level assembler statements. This does not work with LTO where the assembler code may end up in different assembler files. Replace it with extern / global /asm linkage labels. This also removes one redundant copy of the macro. Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1382458079-24450-4-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29x86, asmlinkage, lguest: Fix C functions used by inline assemblerAndi Kleen
- Make the C code used by the paravirt stubs visible - Since they have to be global now, give them a more unique name. Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1382458079-24450-3-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29Merge branch 'x86-intel-mid-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull intel MID cleanups from Peter Anvin: "Miscellaneous cleanups to the intel-mid code merged earlier in this merge window" * 'x86-intel-mid-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, intel-mid: Cleanup some platform code's header files x86, intel-mid: Add missing 'void' to functions without arguments x86: Don't add new __cpuinit users to Merrifield platform code x86: Don't introduce more __cpuinit users in intel_mid_weak_decls.h
2014-01-29Merge branch 'x86-x32-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more x32 uabi type fixes from Peter Anvin: "Despite the branch name, **most of these changes are to generic code**. They change types so that they make an increasing amount of the exported uapi kernel headers usable for libc. The ARM64 people are also interested in these changes for their ILP32 ABI" * 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: uapi: Use __kernel_long_t in struct mq_attr uapi: Use __kernel_ulong_t in shmid64_ds/shminfo64/shm_info x86, uapi, x32: Use __kernel_ulong_t in x86 struct semid64_ds uapi: Use __kernel_ulong_t in struct msqid64_ds uapi: Use __kernel_long_t in struct msgbuf uapi, asm-generic: Use __kernel_ulong_t in uapi struct ipc64_perm uapi: Use __kernel_long_t/__kernel_ulong_t in <linux/resource.h> uapi: Use __kernel_long_t in struct timex
2014-01-29x86, kvm: correctly access the KVM_CPUID_FEATURES leaf at 0x40000101Paolo Bonzini
When Hyper-V hypervisor leaves are present, KVM must relocate its own leaves at 0x40000100, because Windows does not look for Hyper-V leaves at indices other than 0x40000000. In this case, the KVM features are at 0x40000101, but the old code would always look at 0x40000001. Fix by using kvm_cpuid_base(). This also requires making the function non-inline, since kvm_cpuid_base() is static. Fixes: 1085ba7f552d84aa8ac0ae903fa8d0cc2ff9f79d Cc: stable@vger.kernel.org Cc: mtosatti@redhat.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-29x86, kvm: cache the base of the KVM cpuid leavesPaolo Bonzini
It is unnecessary to go through hypervisor_cpuid_base every time a leaf is found (which will be every time a feature is requested after the next patch). Fixes: 1085ba7f552d84aa8ac0ae903fa8d0cc2ff9f79d Cc: stable@vger.kernel.org Cc: mtosatti@redhat.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-29kvm: x86: move KVM_CAP_HYPERV_TIME outside #ifdefPaolo Bonzini
Self explanatory. Reported-by: Radim Krcmar <rkrcmar@redhat.com> Cc: Vadim Rozenfeld <vrozenfe@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-29Merge commit 'f4bcd8ccddb02833340652e9f46f5127828eb79d' into x86/buildH. Peter Anvin
Bring in upstream merge of x86/kaslr for future patches. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-28x86, intel-mid: Cleanup some platform code's header filesDavid Cohen
platform_ipc.h and platform_msic.h are wrongly declaring functions as external and with 'weak' attribute. This patch does a cleanup on those header files. It should have no functional change. Signed-off-by: David Cohen <david.a.cohen@linux.intel.com> Link: http://lkml.kernel.org/r/1390950567-12821-1-git-send-email-david.a.cohen@linux.intel.com Cc: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-27x86: revert wrong memblock current limit settingYinghai Lu
Dave reported big numa system booting is broken. It turns out that commit 5b6e529521d3 ("x86: memblock: set current limit to max low memory address") sets the limit to low wrongly. max_low_pfn_mapped is different from max_pfn_mapped. max_low_pfn_mapped is always under 4G. That will memblock_alloc_nid all go under 4G. Revert 5b6e529521d3 to fix a no-boot regression which was triggered by 457ff1de2d24 ("lib/swiotlb.c: use memblock apis for early memory allocations"). Signed-off-by: Yinghai Lu <yinghai@kernel.org> Reported-by: Dave Hansen <dave.hansen@intel.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-27x86: math-emu: Drop already-disabled print of build dateJosh Triplett
The kernel already has this information, so other bits of kernel code shouldn't duplicate that. This also eliminates the use of __DATE__, which makes the build non-deterministic. This message was already disabled at build time, with PRINT_MESSAGES undef'd at the top of the file. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-01-27KVM: x86: Validate guest writes to MSR_IA32_APICBASEJan Kiszka
Check for invalid state transitions on guest-initiated updates of MSR_IA32_APICBASE. This address both enabling of the x2APIC when it is not supported and all invalid transitions as described in SDM section 10.12.5. It also checks that no reserved bit is set in APICBASE by the guest. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> [Use cpuid_maxphyaddr instead of guest_cpuid_get_phys_bits. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) BPF debugger and asm tool by Daniel Borkmann. 2) Speed up create/bind in AF_PACKET, also from Daniel Borkmann. 3) Correct reciprocal_divide and update users, from Hannes Frederic Sowa and Daniel Borkmann. 4) Currently we only have a "set" operation for the hw timestamp socket ioctl, add a "get" operation to match. From Ben Hutchings. 5) Add better trace events for debugging driver datapath problems, also from Ben Hutchings. 6) Implement auto corking in TCP, from Eric Dumazet. Basically, if we have a small send and a previous packet is already in the qdisc or device queue, defer until TX completion or we get more data. 7) Allow userspace to manage ipv6 temporary addresses, from Jiri Pirko. 8) Add a qdisc bypass option for AF_PACKET sockets, from Daniel Borkmann. 9) Share IP header compression code between Bluetooth and IEEE802154 layers, from Jukka Rissanen. 10) Fix ipv6 router reachability probing, from Jiri Benc. 11) Allow packets to be captured on macvtap devices, from Vlad Yasevich. 12) Support tunneling in GRO layer, from Jerry Chu. 13) Allow bonding to be configured fully using netlink, from Scott Feldman. 14) Allow AF_PACKET users to obtain the VLAN TPID, just like they can already get the TCI. From Atzm Watanabe. 15) New "Heavy Hitter" qdisc, from Terry Lam. 16) Significantly improve the IPSEC support in pktgen, from Fan Du. 17) Allow ipv4 tunnels to cache routes, just like sockets. From Tom Herbert. 18) Add Proportional Integral Enhanced packet scheduler, from Vijay Subramanian. 19) Allow openvswitch to mmap'd netlink, from Thomas Graf. 20) Key TCP metrics blobs also by source address, not just destination address. From Christoph Paasch. 21) Support 10G in generic phylib. From Andy Fleming. 22) Try to short-circuit GRO flow compares using device provided RX hash, if provided. From Tom Herbert. The wireless and netfilter folks have been busy little bees too. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2064 commits) net/cxgb4: Fix referencing freed adapter ipv6: reallocate addrconf router for ipv6 address when lo device up fib_frontend: fix possible NULL pointer dereference rtnetlink: remove IFLA_BOND_SLAVE definition rtnetlink: remove check for fill_slave_info in rtnl_have_link_slave_info qlcnic: update version to 5.3.55 qlcnic: Enhance logic to calculate msix vectors. qlcnic: Refactor interrupt coalescing code for all adapters. qlcnic: Update poll controller code path qlcnic: Interrupt code cleanup qlcnic: Enhance Tx timeout debugging. qlcnic: Use bool for rx_mac_learn. bonding: fix u64 division rtnetlink: add missing IFLA_BOND_AD_INFO_UNSPEC sfc: Use the correct maximum TX DMA ring size for SFC9100 Add Shradha Shah as the sfc driver maintainer. net/vxlan: Share RX skb de-marking and checksum checks with ovs tulip: cleanup by using ARRAY_SIZE() ip_tunnel: clear IPCB in ip_tunnel_xmit() in case dst_link_failure() is called net/cxgb4: Don't retrieve stats during recovery ...
2014-01-25Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "A couple of regression fixes mostly hitting virtualized setups, but also some bare metal systems" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/x86/tsc: Initialize multiplier to 0 sched/clock: Fixup early initialization sched/preempt/x86: Fix voluntary preempt for x86 Revert "sched: Fix sleep time double accounting in enqueue entity"
2014-01-25x86/intel/mid: Fix X86_INTEL_MID dependenciesDavid Cohen
This patch fixes the following warning: warning: (X86_INTEL_MID) selects INTEL_SCU_IPC which has unmet direct dependencies (X86 && X86_PLATFORM_DEVICES && X86_INTEL_MID) It happens because when selected, X86_INTEL_MID tries to select INTEL_SCU_IPC regardless all its dependencies are met or not. This patch fixes it by adding the missing X86_PLATFORM_DEVICES dependency to X86_INTEL_MID. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: David Cohen <david.a.cohen@linux.intel.com> Link: http://lkml.kernel.org/r/1390329699-20782-1-git-send-email-david.a.cohen@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-25Merge branch 'linus' into x86/urgentIngo Molnar
Merge in the x86 changes to apply a fix. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-25arch/x86/mm/srat: Skip NUMA_NO_NODE while parsing SLITToshi Kani
When ACPI SLIT table has an I/O locality (i.e. a locality unique to an I/O device), numa_set_distance() emits this warning message: NUMA: Warning: node ids are out of bound, from=-1 to=-1 distance=10 acpi_numa_slit_init() calls numa_set_distance() with pxm_to_node(), which assumes that all localities have been parsed with SRAT previously. SRAT does not list I/O localities, where as SLIT lists all localities including I/Os. Hence, pxm_to_node() returns NUMA_NO_NODE (-1) for an I/O locality. I/O localities are not supported and are ignored today, but emitting such warning message leads to unnecessary confusion. Change acpi_numa_slit_init() to avoid calling numa_set_distance() with NUMA_NO_NODE. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/n/tip-dSvpjjvp8aMzs1ybkftxohlh@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-25mm, x86: Revisit tlb_flushall_shift tuning for page flushes except on IvyBridgeMel Gorman
There was a large ebizzy performance regression that was bisected to commit 611ae8e3 (x86/tlb: enable tlb flush range support for x86). The problem was related to the tlb_flushall_shift tuning for IvyBridge which was altered. The problem is that it is not clear if the tuning values for each CPU family is correct as the methodology used to tune the values is unclear. This patch uses a conservative tlb_flushall_shift value for all CPU families except IvyBridge so the decision can be revisited if any regression is found as a result of this change. IvyBridge is an exception as testing with one methodology determined that the value of 2 is acceptable. Details are in the changelog for the patch "x86: mm: Change tlb_flushall_shift for IvyBridge". One important aspect of this to watch out for is Xen. The original commit log mentioned large performance gains on Xen. It's possible Xen is more sensitive to this value if it flushes small ranges of pages more frequently than workloads on bare metal typically do. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alex Shi <alex.shi@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-dyzMww3fqugnhbhgo6Gxmtkw@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-25x86: mm: change tlb_flushall_shift for IvyBridgeMel Gorman
There was a large performance regression that was bisected to commit 611ae8e3 ("x86/tlb: enable tlb flush range support for x86"). This patch simply changes the default balance point between a local and global flush for IvyBridge. In the interest of allowing the tests to be reproduced, this patch was tested using mmtests 0.15 with the following configurations configs/config-global-dhp__tlbflush-performance configs/config-global-dhp__scheduler-performance configs/config-global-dhp__network-performance Results are from two machines Ivybridge 4 threads: Intel(R) Core(TM) i3-3240 CPU @ 3.40GHz Ivybridge 8 threads: Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz Page fault microbenchmark showed nothing interesting. Ebizzy was configured to run multiple iterations and threads. Thread counts ranged from 1 to NR_CPUS*2. For each thread count, it ran 100 iterations and each iteration lasted 10 seconds. Ivybridge 4 threads 3.13.0-rc7 3.13.0-rc7 vanilla altshift-v3 Mean 1 6395.44 ( 0.00%) 6789.09 ( 6.16%) Mean 2 7012.85 ( 0.00%) 8052.16 ( 14.82%) Mean 3 6403.04 ( 0.00%) 6973.74 ( 8.91%) Mean 4 6135.32 ( 0.00%) 6582.33 ( 7.29%) Mean 5 6095.69 ( 0.00%) 6526.68 ( 7.07%) Mean 6 6114.33 ( 0.00%) 6416.64 ( 4.94%) Mean 7 6085.10 ( 0.00%) 6448.51 ( 5.97%) Mean 8 6120.62 ( 0.00%) 6462.97 ( 5.59%) Ivybridge 8 threads 3.13.0-rc7 3.13.0-rc7 vanilla altshift-v3 Mean 1 7336.65 ( 0.00%) 7787.02 ( 6.14%) Mean 2 8218.41 ( 0.00%) 9484.13 ( 15.40%) Mean 3 7973.62 ( 0.00%) 8922.01 ( 11.89%) Mean 4 7798.33 ( 0.00%) 8567.03 ( 9.86%) Mean 5 7158.72 ( 0.00%) 8214.23 ( 14.74%) Mean 6 6852.27 ( 0.00%) 7952.45 ( 16.06%) Mean 7 6774.65 ( 0.00%) 7536.35 ( 11.24%) Mean 8 6510.50 ( 0.00%) 6894.05 ( 5.89%) Mean 12 6182.90 ( 0.00%) 6661.29 ( 7.74%) Mean 16 6100.09 ( 0.00%) 6608.69 ( 8.34%) Ebizzy hits the worst case scenario for TLB range flushing every time and it shows for these Ivybridge CPUs at least that the default choice is a poor on. The patch addresses the problem. Next was a tlbflush microbenchmark written by Alex Shi at http://marc.info/?l=linux-kernel&m=133727348217113 . It measures access costs while the TLB is being flushed. The expectation is that if there are always full TLB flushes that the benchmark would suffer and it benefits from range flushing There are 320 iterations of the test per thread count. The number of entries is randomly selected with a min of 1 and max of 512. To ensure a reasonably even spread of entries, the full range is broken up into 8 sections and a random number selected within that section. iteration 1, random number between 0-64 iteration 2, random number between 64-128 etc This is still a very weak methodology. When you do not know what are typical ranges, random is a reasonable choice but it can be easily argued that the opimisation was for smaller ranges and an even spread is not representative of any workload that matters. To improve this, we'd need to know the probability distribution of TLB flush range sizes for a set of workloads that are considered "common", build a synthetic trace and feed that into this benchmark. Even that is not perfect because it would not account for the time between flushes but there are limits of what can be reasonably done and still be doing something useful. If a representative synthetic trace is provided then this benchmark could be revisited and the shift values retuned. Ivybridge 4 threads 3.13.0-rc7 3.13.0-rc7 vanilla altshift-v3 Mean 1 10.50 ( 0.00%) 10.50 ( 0.03%) Mean 2 17.59 ( 0.00%) 17.18 ( 2.34%) Mean 3 22.98 ( 0.00%) 21.74 ( 5.41%) Mean 5 47.13 ( 0.00%) 46.23 ( 1.92%) Mean 8 43.30 ( 0.00%) 42.56 ( 1.72%) Ivybridge 8 threads 3.13.0-rc7 3.13.0-rc7 vanilla altshift-v3 Mean 1 9.45 ( 0.00%) 9.36 ( 0.93%) Mean 2 9.37 ( 0.00%) 9.70 ( -3.54%) Mean 3 9.36 ( 0.00%) 9.29 ( 0.70%) Mean 5 14.49 ( 0.00%) 15.04 ( -3.75%) Mean 8 41.08 ( 0.00%) 38.73 ( 5.71%) Mean 13 32.04 ( 0.00%) 31.24 ( 2.49%) Mean 16 40.05 ( 0.00%) 39.04 ( 2.51%) For both CPUs, average access time is reduced which is good as this is the benchmark that was used to tune the shift values in the first place albeit it is now known *how* the benchmark was used. The scheduler benchmarks were somewhat inconclusive. They showed gains and losses and makes me reconsider how stable those benchmarks really are or if something else might be interfering with the test results recently. Network benchmarks were inconclusive. Almost all results were flat except for netperf-udp tests on the 4 thread machine. These results were unstable and showed large variations between reboots. It is unknown if this is a recent problems but I've noticed before that netperf-udp results tend to vary. Based on these results, changing the default for Ivybridge seems like a logical choice. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Reviewed-by: Alex Shi <alex.shi@linaro.org> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-cqnadffh1tiqrshthRj3Esge@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>