1. 02 Oct, 2015 24 commits
    • Trond Myklebust's avatar
      NFS: Fix a write performance regression · 8fa4592a
      Trond Myklebust authored
      If all other conditions in nfs_can_extend_write() are met, and there
      are no locks, then we should be able to assume close-to-open semantics
      and the ability to extend our write to cover the whole page.
      
      With this patch, the xfstests generic/074 test completes in 242s instead
      of >1400s on my test rig.
      
      Fixes: bd61e0a9 ("locks: convert posix locks to file_lock_context")
      Cc: Jeff Layton <jlayton@primarydata.com>
      Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
      8fa4592a
    • Trond Myklebust's avatar
      NFS: Fix up page writeback accounting · 40f90271
      Trond Myklebust authored
      Currently, we are crediting all the calls to nfs_writepages_callback()
      (i.e. the nfs_writepages() callback) to nfs_writepage(). Aside from
      being inconsistent with the behaviour of the equivalent readpage/readpages
      accounting, this also means that we cannot distinguish between bulk writes
      and single page writebacks (which confuses the 'nfsiostat -p' tool).
      Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
      40f90271
    • Linus Torvalds's avatar
      Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux · 5634347d
      Linus Torvalds authored
      Pull arm64 fixes from Catalin Marinas:
      
       - Fix for transparent huge page change_protection() logic which was
         inadvertently changing a huge pmd page into a pmd table entry.
      
       - Function graph tracer panic fix caused by the return_to_handler code
         corrupting the multi-regs function return value (composite types).
      
      * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
        arm64: ftrace: fix function_graph tracer panic
        arm64: Fix THP protection change logic
      5634347d
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k · b55a97e7
      Linus Torvalds authored
      Pull m68k updates from Geert Uytterhoeven:
       "Summary:
         - Fix for accidental modification of arguments of syscall functions
         - Wire up new syscalls
         - Update defconfigs"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
        m68k/defconfig: Update defconfigs for v4.3-rc1
        m68k: Define asmlinkage_protect
        m68k: Wire up membarrier
        m68k: Wire up userfaultfd
        m68k: Wire up direct socket calls
      b55a97e7
    • Linus Torvalds's avatar
      Merge tag 'dmaengine-fix-4.3-rc4' of git://git.infradead.org/users/vkoul/slave-dma · 83dc311c
      Linus Torvalds authored
      Pull dmaengine fixes from Vinod Koul:
       "This contains fixes spread throughout the drivers, and also fixes one
        more instance of privatecnt in dmaengine.
      
        Driver fixes summary:
         - bunch of pxa_dma fixes for reuse of descriptor issue, residue and
           no-requestor
         - odd fixes in xgene, idma, sun4i and zxdma
         - at_xdmac fixes for cleaning descriptor and block addr mode"
      
      * tag 'dmaengine-fix-4.3-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
        dmaengine: pxa_dma: fix residue corner case
        dmaengine: pxa_dma: fix the no-requestor case
        dmaengine: zxdma: Fix off-by-one for testing valid pchan request
        dmaengine: at_xdmac: clean used descriptor
        dmaengine: at_xdmac: change block increment addressing mode
        dmaengine: dw: properly read DWC_PARAMS register
        dmaengine: xgene-dma: Fix overwritting DMA tx ring
        dmaengine: fix balance of privatecnt
        dmaengine: sun4i: fix unsafe list iteration
        dmaengine: idma64: improve residue estimation
        dmaengine: xgene-dma: fix handling xgene_dma_get_ring_size result
        dmaengine: pxa_dma: fix initial list move
      83dc311c
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.dk/linux-block · 27728bf0
      Linus Torvalds authored
      Pull block fixes from Jens Axboe:
       "Another week, another round of fixes.
      
        These have been brewing for a bit and in various iterations, but I
        feel pretty comfortable about the quality of them.  They fix real
        issues.  The pull request is mostly blk-mq related, and the only one
        not fixing a real bug, is the tag iterator abstraction from Christoph.
        But it's pretty trivial, and we'll need it for another fix soon.
      
        Apart from the blk-mq fixes, there's an NVMe affinity fix from Keith,
        and a single fix for xen-blkback from Roger fixing failure to free
        requests on disconnect"
      
      * 'for-linus' of git://git.kernel.dk/linux-block:
        blk-mq: factor out a helper to iterate all tags for a request_queue
        blk-mq: fix racy updates of rq->errors
        blk-mq: fix deadlock when reading cpu_list
        blk-mq: avoid inserting requests before establishing new mapping
        blk-mq: fix q->mq_usage_counter access race
        blk-mq: Fix use after of free q->mq_map
        blk-mq: fix sysfs registration/unregistration race
        blk-mq: avoid setting hctx->tags->cpumask before allocation
        NVMe: Set affinity after allocating request queues
        xen/blkback: free requests on disconnection
      27728bf0
    • Linus Torvalds's avatar
      Merge tag 'mmc-v4.3-rc3' of git://git.linaro.org/people/ulf.hansson/mmc · 36f8dafe
      Linus Torvalds authored
      Pull MMC fixes from Ulf Hansson:
       "Here are some mmc fixes intended for v4.3 rc4:
      
        MMC core:
         - Allow users of mmc_of_parse() to succeed when CONFIG_GPIOLIB is
           unset
         - Prevent infinite loop of re-tuning for CRC-errors for CMD19 and
           CMD21
      
         MMC host:
         - pxamci: Fix issues with card detect
         - sunxi: Fix clk-delay settings"
      
      * tag 'mmc-v4.3-rc3' of git://git.linaro.org/people/ulf.hansson/mmc:
        mmc: core: fix dead loop of mmc_retune
        mmc: pxamci: fix card detect with slot-gpio API
        mmc: sunxi: Fix clk-delay settings
        mmc: core: Don't return an error for CD/WP GPIOs when GPIOLIB is unset
      36f8dafe
    • Linus Torvalds's avatar
      Merge git://git.infradead.org/intel-iommu · 8c25ab8b
      Linus Torvalds authored
      Pull IOVA fixes from David Woodhouse:
       "The main fix here is the first one, fixing the over-allocation of
         size-aligned requests.  The other patches simply make the existing
        IOVA code available to users other than the Intel VT-d driver, with no
        functional change.
      
        I concede the latter really *should* have been submitted during the
        merge window, but since it's basically risk-free and people are
        waiting to build on top of it and it's my fault I didn't get it in, I
        (and they) would be grateful if you'd take it"
      
      * git://git.infradead.org/intel-iommu:
        iommu: Make the iova library a module
        iommu: iova: Export symbols
        iommu: iova: Move iova cache management to the iova library
        iommu/iova: Avoid over-allocating when size-aligned
      8c25ab8b
    • Li Bin's avatar
      arm64: ftrace: fix function_graph tracer panic · ee556d00
      Li Bin authored
      When function graph tracer is enabled, the following operation
      will trigger panic:
      
      mount -t debugfs nodev /sys/kernel
      echo next_tgid > /sys/kernel/tracing/set_ftrace_filter
      echo function_graph > /sys/kernel/tracing/current_tracer
      ls /proc/
      
      ------------[ cut here ]------------
      [  198.501417] Unable to handle kernel paging request at virtual address cb88537fdc8ba316
      [  198.506126] pgd = ffffffc008f79000
      [  198.509363] [cb88537fdc8ba316] *pgd=00000000488c6003, *pud=00000000488c6003, *pmd=0000000000000000
      [  198.517726] Internal error: Oops: 94000005 [#1] SMP
      [  198.518798] Modules linked in:
      [  198.520582] CPU: 1 PID: 1388 Comm: ls Tainted: G
      [  198.521800] Hardware name: linux,dummy-virt (DT)
      [  198.522852] task: ffffffc0fa9e8000 ti: ffffffc0f9ab0000 task.ti: ffffffc0f9ab0000
      [  198.524306] PC is at next_tgid+0x30/0x100
      [  198.525205] LR is at return_to_handler+0x0/0x20
      [  198.526090] pc : [<ffffffc0002a1070>] lr : [<ffffffc0000907c0>] pstate: 60000145
      [  198.527392] sp : ffffffc0f9ab3d40
      [  198.528084] x29: ffffffc0f9ab3d40 x28: ffffffc0f9ab0000
      [  198.529406] x27: ffffffc000d6a000 x26: ffffffc000b786e8
      [  198.530659] x25: ffffffc0002a1900 x24: ffffffc0faf16c00
      [  198.531942] x23: ffffffc0f9ab3ea0 x22: 0000000000000002
      [  198.533202] x21: ffffffc000d85050 x20: 0000000000000002
      [  198.534446] x19: 0000000000000002 x18: 0000000000000000
      [  198.535719] x17: 000000000049fa08 x16: ffffffc000242efc
      [  198.537030] x15: 0000007fa472b54c x14: ffffffffff000000
      [  198.538347] x13: ffffffc0fada84a0 x12: 0000000000000001
      [  198.539634] x11: ffffffc0f9ab3d70 x10: ffffffc0f9ab3d70
      [  198.540915] x9 : ffffffc0000907c0 x8 : ffffffc0f9ab3d40
      [  198.542215] x7 : 0000002e330f08f0 x6 : 0000000000000015
      [  198.543508] x5 : 0000000000000f08 x4 : ffffffc0f9835ec0
      [  198.544792] x3 : cb88537fdc8ba316 x2 : cb88537fdc8ba306
      [  198.546108] x1 : 0000000000000002 x0 : ffffffc000d85050
      [  198.547432]
      [  198.547920] Process ls (pid: 1388, stack limit = 0xffffffc0f9ab0020)
      [  198.549170] Stack: (0xffffffc0f9ab3d40 to 0xffffffc0f9ab4000)
      [  198.582568] Call trace:
      [  198.583313] [<ffffffc0002a1070>] next_tgid+0x30/0x100
      [  198.584359] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
      [  198.585503] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
      [  198.586574] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
      [  198.587660] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
      [  198.588896] Code: aa0003f5 2a0103f4 b4000102 91004043 (885f7c60)
      [  198.591092] ---[ end trace 6a346f8f20949ac8 ]---
      
      This is because when using function graph tracer, if the traced
      function return value is in multi regs ([x0-x7]), return_to_handler
      may corrupt them. So in return_to_handler, the parameter regs should
      be protected properly.
      
      Cc: <stable@vger.kernel.org> # 3.18+
      Signed-off-by: default avatarLi Bin <huawei.libin@huawei.com>
      Acked-by: default avatarAKASHI Takahiro <takahiro.akashi@linaro.org>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      ee556d00
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · bde17b90
      Linus Torvalds authored
      Merge misc fixes from Andrew Morton:
       "12 fixes"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>:
        dmapool: fix overflow condition in pool_find_page()
        thermal: avoid division by zero in power allocator
        memcg: remove pcp_counter_lock
        kprobes: use _do_fork() in samples to make them work again
        drivers/input/joystick/Kconfig: zhenhua.c needs BITREVERSE
        memcg: make mem_cgroup_read_stat() unsigned
        memcg: fix dirty page migration
        dax: fix NULL pointer in __dax_pmd_fault()
        mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault
        mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1)
        userfaultfd: remove kernel header include from uapi header
        arch/x86/include/asm/efi.h: fix build failure
      bde17b90
    • Linus Torvalds's avatar
      Merge tag 'pm+acpi-4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · 1bca1000
      Linus Torvalds authored
      Pull power management and ACPI fixes from Rafael Wysocki:
       "These are fixes mostly, for a few changes made in this cycle (the
        intel_idle driver, the OPP library, the ACPI EC driver, turbostat) and
        for some issues that have just been discovered (ACPI PCI IRQ
        management, PCI power management documentation, turbostat), with a
        couple of cleanups on top of them.
      
        Specifics:
      
         - intel_idle driver fixup for the recently added Skylake chips
           support (Len Brown).
      
         - Operating Performance Points (OPP) library fix related to the
           recently added support for new DT bindings and a fix for a typo in
           a comment (Viresh Kumar, Stephen Boyd).
      
         - ACPI EC driver fix for a recently introduced memory leak in an
           error code path (Lv Zheng).
      
         - ACPI PCI IRQ management fix for the issue where an ISA IRQ is
           shared with a PCI device which requires it to be configured in a
           different way and may cause an interrupt storm to happen as a
           result with an extra ACPI SCI IRQ handling simplification on top of
           it (Jiang Liu).
      
         - Update of the PCI power management documentation that became
           outdated and started to actively confuse the readers to make it
           actually reflect the code (Rafael J Wysocki).
      
         - turbostat fixes including an IVB Xeon regression fix (related to
           the --debug command line option), Skylake adjustment for the TSC
           running at a frequency that doesn't match the base one exactly, and
           a Knights Landing quirk to account for the fact that it only
           updates APERF and MPERF every 1024 clock cycles plus bumping up the
           turbostat version number (Len Brown, Hubert Chrzaniuk)"
      
      * tag 'pm+acpi-4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
        tools/power turbosat: update version number
        tools/power turbostat: SKL: Adjust for TSC difference from base frequency
        tools/power turbostat: KNL workaround for %Busy and Avg_MHz
        tools/power turbostat: IVB Xeon: fix --debug regression
        ACPI / PCI: Remove duplicated penalty on SCI IRQ
        ACPI, PCI, irq: Do not share PCI IRQ with ISA IRQ
        ACPI / EC: Fix a memory leak issue in acpi_ec_query()
        PM / OPP: Fix typo modifcation -> modification
        PCI / PM: Update runtime PM documentation for PCI devices
        PM / OPP: of_property_count_u32_elems() can return errors
        intel_idle: Skylake Client Support - updated
      1bca1000
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 3deaa4f5
      Linus Torvalds authored
      Pull networking fixes from David Miller:
      
      1) Fix regression in SKB partial checksum handling, from Pravin B
         Shalar.
      
      2) Fix VLAN inside of VXLAN handling in i40e driver, from Jesse
         Brandeburg.
      
      3) Cure softlockups during accept() in SCTP, from Karl Heiss.
      
      4) MSG_PEEK should return multiple SKBs worth of data in AF_UNIX, from
         Aaron Conole.
      
      5) IPV6 erroneously ignores output interface specifier in lookup key for
         route lookups, fix from David Ahern.
      
      6) In Marvell DSA driver, forward unknown frames to CPU port, from
         Andrew Lunn.
      
      7) Mission flow flag initializations in some code paths, from David
         Ahern.
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
        net: Initialize flow flags in input path
        net: dsa: fix preparation of a port STP update
        testptp: Silence compiler warnings on ppc64
        net/mlx4: Handle return codes in mlx4_qp_attach_common
        dsa: mv88e6xxx: Enable forwarding for unknown to the CPU port
        skbuff: Fix skb checksum partial check.
        net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set
        net sysfs: Print link speed as signed integer
        bna: fix error handling
        af_unix: return data from multiple SKBs on recv() with MSG_PEEK flag
        af_unix: Convert the unix_sk macro to an inline function for type safety
        net: sctp: Don't use 64 kilobyte lookup table for four elements
        l2tp: protect tunnel->del_work by ref_count
        net/ibm/emac: bump version numbers for correct work with ethtool
        sctp: Prevent soft lockup when sctp_accept() is called during a timeout event
        sctp: Whitespace fix
        i40e/i40evf: check for stopped admin queue
        i40e: fix VLAN inside VXLAN
        r8169: fix handling rtl_readphy result
        net: hisilicon: fix handling platform_get_irq result
      3deaa4f5
    • Robin Murphy's avatar
      dmapool: fix overflow condition in pool_find_page() · 676bd991
      Robin Murphy authored
      If a DMA pool lies at the very top of the dma_addr_t range (as may
      happen with an IOMMU involved), the calculated end address of the pool
      wraps around to zero, and page lookup always fails.
      
      Tweak the relevant calculation to be overflow-proof.
      Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Marek Szyprowski <m.szyprowski@samsung.com>
      Cc: Sumit Semwal <sumit.semwal@linaro.org>
      Cc: Sakari Ailus <sakari.ailus@iki.fi>
      Cc: Russell King <rmk+kernel@arm.linux.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      676bd991
    • Andrea Arcangeli's avatar
      thermal: avoid division by zero in power allocator · 44241628
      Andrea Arcangeli authored
      During boot I get a div by zero Oops regression starting in v4.3-rc3.
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Reviewed-by: default avatarJavi Merino <javi.merino@arm.com>
      Cc: Zhang Rui <rui.zhang@intel.com>
      Cc: Eduardo Valentin <edubezval@gmail.com>
      Cc: Daniel Kurtz <djkurtz@chromium.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      44241628
    • Greg Thelen's avatar
      memcg: remove pcp_counter_lock · ef510194
      Greg Thelen authored
      Commit 733a572e ("memcg: make mem_cgroup_read_{stat|event}() iterate
      possible cpus instead of online") removed the last use of the per memcg
      pcp_counter_lock but forgot to remove the variable.
      
      Kill the vestigial variable.
      Signed-off-by: default avatarGreg Thelen <gthelen@google.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ef510194
    • Petr Mladek's avatar
      kprobes: use _do_fork() in samples to make them work again · 54aea454
      Petr Mladek authored
      Commit 3033f14a ("clone: support passing tls argument via C rather
      than pt_regs magic") introduced _do_fork() that allowed to pass @tls
      parameter.
      
      The old do_fork() is defined only for architectures that are not ready
      to use this way and do not define HAVE_COPY_THREAD_TLS.
      
      Let's use _do_fork() in the kprobe examples to make them work again on
      all architectures.
      Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Thiago Macieira <thiago.macieira@intel.com>
      Cc: Jiri Kosina <jkosina@suse.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      54aea454
    • Andrew Morton's avatar
      drivers/input/joystick/Kconfig: zhenhua.c needs BITREVERSE · 09a59a9d
      Andrew Morton authored
      It uses bitrev8(), so it must ensure that lib/bitrev.o gets included in
      vmlinux.
      
      Cc: Fengguang Wu <fengguang.wu@gmail.com>
      Cc: yalin wang <yalin.wang2010@gmail.com>
      Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      09a59a9d
    • Greg Thelen's avatar
      memcg: make mem_cgroup_read_stat() unsigned · 484ebb3b
      Greg Thelen authored
      mem_cgroup_read_stat() returns a page count by summing per cpu page
      counters.  The summing is racy wrt.  updates, so a transient negative
      sum is possible.  Callers don't want negative values:
      
       - mem_cgroup_wb_stats() doesn't want negative nr_dirty or nr_writeback.
         This could confuse dirty throttling.
      
       - oom reports and memory.stat shouldn't show confusing negative usage.
      
       - tree_usage() already avoids negatives.
      
      Avoid returning negative page counts from mem_cgroup_read_stat() and
      convert it to unsigned.
      
      [akpm@linux-foundation.org: fix old typo while we're in there]
      Signed-off-by: default avatarGreg Thelen <gthelen@google.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: <stable@vger.kernel.org>	[4.2+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      484ebb3b
    • Greg Thelen's avatar
      memcg: fix dirty page migration · 0610c25d
      Greg Thelen authored
      The problem starts with a file backed dirty page which is charged to a
      memcg.  Then page migration is used to move oldpage to newpage.
      
      Migration:
       - copies the oldpage's data to newpage
       - clears oldpage.PG_dirty
       - sets newpage.PG_dirty
       - uncharges oldpage from memcg
       - charges newpage to memcg
      
      Clearing oldpage.PG_dirty decrements the charged memcg's dirty page
      count.
      
      However, because newpage is not yet charged, setting newpage.PG_dirty
      does not increment the memcg's dirty page count.  After migration
      completes newpage.PG_dirty is eventually cleared, often in
      account_page_cleaned().  At this time newpage is charged to a memcg so
      the memcg's dirty page count is decremented which causes underflow
      because the count was not previously incremented by migration.  This
      underflow causes balance_dirty_pages() to see a very large unsigned
      number of dirty memcg pages which leads to aggressive throttling of
      buffered writes by processes in non root memcg.
      
      This issue:
       - can harm performance of non root memcg buffered writes.
       - can report too small (even negative) values in
         memory.stat[(total_)dirty] counters of all memcg, including the root.
      
      To avoid polluting migrate.c with #ifdef CONFIG_MEMCG checks, introduce
      page_memcg() and set_page_memcg() helpers.
      
      Test:
          0) setup and enter limited memcg
          mkdir /sys/fs/cgroup/test
          echo 1G > /sys/fs/cgroup/test/memory.limit_in_bytes
          echo $$ > /sys/fs/cgroup/test/cgroup.procs
      
          1) buffered writes baseline
          dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
          sync
          grep ^dirty /sys/fs/cgroup/test/memory.stat
      
          2) buffered writes with compaction antagonist to induce migration
          yes 1 > /proc/sys/vm/compact_memory &
          rm -rf /data/tmp/foo
          dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
          kill %
          sync
          grep ^dirty /sys/fs/cgroup/test/memory.stat
      
          3) buffered writes without antagonist, should match baseline
          rm -rf /data/tmp/foo
          dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
          sync
          grep ^dirty /sys/fs/cgroup/test/memory.stat
      
                             (speed, dirty residue)
                   unpatched                       patched
          1) 841 MB/s 0 dirty pages          886 MB/s 0 dirty pages
          2) 611 MB/s -33427456 dirty pages  793 MB/s 0 dirty pages
          3) 114 MB/s -33427456 dirty pages  891 MB/s 0 dirty pages
      
          Notice that unpatched baseline performance (1) fell after
          migration (3): 841 -> 114 MB/s.  In the patched kernel, post
          migration performance matches baseline.
      
      Fixes: c4843a75 ("memcg: add per cgroup dirty page accounting")
      Signed-off-by: default avatarGreg Thelen <gthelen@google.com>
      Reported-by: default avatarDave Hansen <dave.hansen@intel.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Cc: <stable@vger.kernel.org>	[4.2+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0610c25d
    • Ross Zwisler's avatar
      dax: fix NULL pointer in __dax_pmd_fault() · 8346c416
      Ross Zwisler authored
      Commit 46c043ed ("mm: take i_mmap_lock in unmap_mapping_range() for
      DAX") moved some code in __dax_pmd_fault() that was responsible for
      zeroing newly allocated PMD pages.  The new location didn't properly set
      up 'kaddr', so when run this code resulted in a NULL pointer BUG.
      
      Fix this by getting the correct 'kaddr' via bdev_direct_access().
      Signed-off-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
      Reported-by: default avatarDan Williams <dan.j.williams@intel.com>
      Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Matthew Wilcox <willy@linux.intel.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8346c416
    • Mel Gorman's avatar
      mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault · 2f84a899
      Mel Gorman authored
      SunDong reported the following on
      
        https://bugzilla.kernel.org/show_bug.cgi?id=103841
      
      	I think I find a linux bug, I have the test cases is constructed. I
      	can stable recurring problems in fedora22(4.0.4) kernel version,
      	arch for x86_64.  I construct transparent huge page, when the parent
      	and child process with MAP_SHARE, MAP_PRIVATE way to access the same
      	huge page area, it has the opportunity to lead to huge page copy on
      	write failure, and then it will munmap the child corresponding mmap
      	area, but then the child mmap area with VM_MAYSHARE attributes, child
      	process munmap this area can trigger VM_BUG_ON in set_vma_resv_flags
      	functions (vma - > vm_flags & VM_MAYSHARE).
      
      There were a number of problems with the report (e.g.  it's hugetlbfs that
      triggers this, not transparent huge pages) but it was fundamentally
      correct in that a VM_BUG_ON in set_vma_resv_flags() can be triggered that
      looks like this
      
      	 vma ffff8804651fd0d0 start 00007fc474e00000 end 00007fc475e00000
      	 next ffff8804651fd018 prev ffff8804651fd188 mm ffff88046b1b1800
      	 prot 8000000000000027 anon_vma           (null) vm_ops ffffffff8182a7a0
      	 pgoff 0 file ffff88106bdb9800 private_data           (null)
      	 flags: 0x84400fb(read|write|shared|mayread|maywrite|mayexec|mayshare|dontexpand|hugetlb)
      	 ------------
      	 kernel BUG at mm/hugetlb.c:462!
      	 SMP
      	 Modules linked in: xt_pkttype xt_LOG xt_limit [..]
      	 CPU: 38 PID: 26839 Comm: map Not tainted 4.0.4-default #1
      	 Hardware name: Dell Inc. PowerEdge R810/0TT6JF, BIOS 2.7.4 04/26/2012
      	 set_vma_resv_flags+0x2d/0x30
      
      The VM_BUG_ON is correct because private and shared mappings have
      different reservation accounting but the warning clearly shows that the
      VMA is shared.
      
      When a private COW fails to allocate a new page then only the process
      that created the VMA gets the page -- all the children unmap the page.
      If the children access that data in the future then they get killed.
      
      The problem is that the same file is mapped shared and private.  During
      the COW, the allocation fails, the VMAs are traversed to unmap the other
      private pages but a shared VMA is found and the bug is triggered.  This
      patch identifies such VMAs and skips them.
      Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
      Reported-by: default avatarSunDong <sund_sky@126.com>
      Reviewed-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: David Rientjes <rientjes@google.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2f84a899
    • Joonsoo Kim's avatar
      mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1) · 03a2d2a3
      Joonsoo Kim authored
      Commit description is copied from the original post of this bug:
      
        http://comments.gmane.org/gmane.linux.kernel.mm/135349
      
      Kernels after v3.9 use kmalloc_size(INDEX_NODE + 1) to get the next
      larger cache size than the size index INDEX_NODE mapping.  In kernels
      3.9 and earlier we used malloc_sizes[INDEX_L3 + 1].cs_size.
      
      However, sometimes we can't get the right output we expected via
      kmalloc_size(INDEX_NODE + 1), causing a BUG().
      
      The mapping table in the latest kernel is like:
          index = {0,   1,  2 ,  3,  4,   5,   6,   n}
           size = {0,   96, 192, 8, 16,  32,  64,   2^n}
      The mapping table before 3.10 is like this:
          index = {0 , 1 , 2,   3,  4 ,  5 ,  6,   n}
          size  = {32, 64, 96, 128, 192, 256, 512, 2^(n+3)}
      
      The problem on my mips64 machine is as follows:
      
      (1) When configured DEBUG_SLAB && DEBUG_PAGEALLOC && DEBUG_LOCK_ALLOC
          && DEBUG_SPINLOCK, the sizeof(struct kmem_cache_node) will be "150",
          and the macro INDEX_NODE turns out to be "2": #define INDEX_NODE
          kmalloc_index(sizeof(struct kmem_cache_node))
      
      (2) Then the result of kmalloc_size(INDEX_NODE + 1) is 8.
      
      (3) Then "if(size >= kmalloc_size(INDEX_NODE + 1)" will lead to "size
          = PAGE_SIZE".
      
      (4) Then "if ((size >= (PAGE_SIZE >> 3))" test will be satisfied and
          "flags |= CFLGS_OFF_SLAB" will be covered.
      
      (5) if (flags & CFLGS_OFF_SLAB)" test will be satisfied and will go to
          "cachep->slabp_cache = kmalloc_slab(slab_size, 0u)", and the result
          here may be NULL while kernel bootup.
      
      (6) Finally,"BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));" causes the
          BUG info as the following shows (may be only mips64 has this problem):
      
      This patch fixes the problem of kmalloc_size(INDEX_NODE + 1) and removes
      the BUG by adding 'size >= 256' check to guarantee that all necessary
      small sized slabs are initialized regardless sequence of slab size in
      mapping table.
      
      Fixes: e3366016 ("slab: Use common kmalloc_index/kmalloc_size...")
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Reported-by: default avatarLiuhailong <liu.hailong6@zte.com.cn>
      Acked-by: default avatarChristoph Lameter <cl@linux.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      03a2d2a3
    • Andre Przywara's avatar
      userfaultfd: remove kernel header include from uapi header · 9ff42d10
      Andre Przywara authored
      As include/uapi/linux/userfaultfd.h is a user visible header file, it
      should not include kernel-exclusive header files.
      
      So trying to build the userfaultfd test program from the selftests
      directory fails, since it contains a reference to linux/compiler.h.  As
      it turns out, that header is not really needed there, so we can simply
      remove it to fix that issue.
      Signed-off-by: default avatarAndre Przywara <andre.przywara@arm.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Shuah Khan <shuahkh@osg.samsung.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9ff42d10
    • Andrey Ryabinin's avatar
      arch/x86/include/asm/efi.h: fix build failure · a523841e
      Andrey Ryabinin authored
      With KMEMCHECK=y, KASAN=n:
      
        arch/x86/platform/efi/efi.c:673:3: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]
        arch/x86/platform/efi/efi_64.c:139:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]
        arch/x86/include/asm/desc.h:121:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]
      
      Don't #undef memcpy if KASAN=n.
      
      Fixes: 769a8089 ("x86, efi, kasan: #undef memset/memcpy/memmove per arch")
      Signed-off-by: default avatarAndrey Ryabinin <ryabinin.a.a@gmail.com>
      Reported-by: default avatarIngo Molnar <mingo@kernel.org>
      Reported-by: default avatarSedat Dilek <sedat.dilek@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a523841e
  2. 01 Oct, 2015 16 commits