1. 21 Sep, 2012 14 commits
  2. 19 Sep, 2012 10 commits
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.dk/linux-block · c46de226
      Linus Torvalds authored
      Pull block fixes from Jens Axboe:
       "A small collection of driver fixes/updates and a core fix for 3.6.  It
        contains:
      
         - Bug fixes for mtip32xx, and support for new hardware (just addition
           of IDs).  They have been queued up for 3.7 for a few weeks as well.
      
         - rate-limit a failing command error message in block core.
      
         - A fix for an old cciss bug from Stephen.
      
         - Prevent overflow of partition count from Alan."
      
      * 'for-linus' of git://git.kernel.dk/linux-block:
        cciss: fix handling of protocol error
        blk: add an upper sanity check on partition adding
        mtip32xx: fix user_buffer check in exec_drive_command
        mtip32xx: Remove dead code
        mtip32xx: Change printk to pr_xxxx
        mtip32xx: Proper reporting of write protect status on big-endian
        mtip32xx: Increase timeout for standby command
        mtip32xx: Handle NCQ commands during the security locked state
        mtip32xx: Add support for new devices
        block: rate-limit the error message from failing commands
      c46de226
    • Linus Torvalds's avatar
      Merge tag 'sh-for-linus' of git://github.com/pmundt/linux-sh · 077fee00
      Linus Torvalds authored
      Pull SuperH fixes from Paul Mundt.
      
      * tag 'sh-for-linus' of git://github.com/pmundt/linux-sh:
        sh: Fix up TIF_NOTIFY_RESUME sans TIF_SIGPENDING handling.
        sh: pfc: Release spinlock in sh_pfc_gpio_request_enable() error path
        sh: intc: Fix up multi-evt irq association.
      077fee00
    • Linus Torvalds's avatar
      Merge tag 'rpmsg-3.6-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/rpmsg · cf42d543
      Linus Torvalds authored
      Pull rpmsg fix from Ohad Ben-Cohen:
       "A quick rpmsg fix from Fernando, fixing two buggy invocations of
        dma_free_coherent"
      
      * tag 'rpmsg-3.6-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/rpmsg:
        rpmsg: fix dma_free_coherent dev parameter
      cf42d543
    • Linus Torvalds's avatar
      Merge tag 'md-3.6-fixes' of git://neil.brown.name/md · 4b92c17e
      Linus Torvalds authored
      Pull md fixes from NeilBrown:
       "3 fixes for md in 3.6.
      
        One reverts a recent patch which turns out to not be such a good idea.
      
        Other two fix minor bugs with the new (since 3.3) 'replacement' code
        and have been tagged for -stable."
      
      * tag 'md-3.6-fixes' of git://neil.brown.name/md:
        md: make sure metadata is updated when spares are activated or removed.
        md/raid5: fix calculate of 'degraded' when a replacement becomes active.
        Revert "md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE."
      4b92c17e
    • Linus Torvalds's avatar
      Merge branch 'for-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq · c5c473e2
      Linus Torvalds authored
      Pull workqueue / powernow-k8 fix from Tejun Heo:
       "This is the fix for the bug where cpufreq/powernow-k8 was tripping
        BUG_ON() in try_to_wake_up_local() by migrating workqueue worker to a
        different CPU.
      
          https://bugzilla.kernel.org/show_bug.cgi?id=47301
      
        As discussed, the fix is now two parts - one to reimplement
        work_on_cpu() so that it doesn't create a new kthread each time and
        the actual fix which makes powernow-k8 use work_on_cpu() instead of
        performing manual migration.
      
        While pretty late in the merge cycle, both changes are on the safer
        side.  Jiri and I verified two existing users of work_on_cpu() and
        Duncan confirmed that the powernow-k8 fix survived about 18 hours of
        testing."
      
      * 'for-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
        cpufreq/powernow-k8: workqueue user shouldn't migrate the kworker to another CPU
        workqueue: reimplement work_on_cpu() using system_wq
      c5c473e2
    • Tejun Heo's avatar
      cpufreq/powernow-k8: workqueue user shouldn't migrate the kworker to another CPU · 6889125b
      Tejun Heo authored
      powernowk8_target() runs off a per-cpu work item and if the
      cpufreq_policy->cpu is different from the current one, it migrates the
      kworker to the target CPU by manipulating current->cpus_allowed.  The
      function migrates the kworker back to the original CPU but this is
      still broken.  Workqueue concurrency management requires the kworkers
      to stay on the same CPU and powernowk8_target() ends up triggerring
      BUG_ON(rq != this_rq()) in try_to_wake_up_local() if it contends on
      fidvid_mutex and sleeps.
      
      It is unclear why this bug is being reported now.  Duncan says it
      appeared to be a regression of 3.6-rc1 and couldn't reproduce it on
      3.5.  Bisection seemed to point to 63d95a91 "workqueue: use @pool
      instead of @gcwq or @cpu where applicable" which is an non-functional
      change.  Given that the reproduce case sometimes took upto days to
      trigger, it's easy to be misled while bisecting.  Maybe something made
      contention on fidvid_mutex more likely?  I don't know.
      
      This patch fixes the bug by using work_on_cpu() instead if @pol->cpu
      isn't the same as the current one.  The code assumes that
      cpufreq_policy->cpu is kept online by the caller, which Rafael tells
      me is the case.
      
      stable: ed48ece2 ("workqueue: reimplement work_on_cpu() using
              system_wq") should be applied before this; otherwise, the
              behavior could be horrible.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Reported-by: default avatarDuncan <1i5t5.duncan@cox.net>
      Tested-by: default avatarDuncan <1i5t5.duncan@cox.net>
      Cc: Rafael J. Wysocki <rjw@sisk.pl>
      Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
      Cc: stable@vger.kernel.org
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=47301
      6889125b
    • Tejun Heo's avatar
      workqueue: reimplement work_on_cpu() using system_wq · ed48ece2
      Tejun Heo authored
      The existing work_on_cpu() implementation is hugely inefficient.  It
      creates a new kthread, execute that single function and then let the
      kthread die on each invocation.
      
      Now that system_wq can handle concurrent executions, there's no
      advantage of doing this.  Reimplement work_on_cpu() using system_wq
      which makes it simpler and way more efficient.
      
      stable: While this isn't a fix in itself, it's needed to fix a
              workqueue related bug in cpufreq/powernow-k8.  AFAICS, this
              shouldn't break other existing users.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Acked-by: default avatarJiri Kosina <jkosina@suse.cz>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Bjorn Helgaas <bhelgaas@google.com>
      Cc: Len Brown <lenb@kernel.org>
      Cc: Rafael J. Wysocki <rjw@sisk.pl>
      Cc: stable@vger.kernel.org
      ed48ece2
    • NeilBrown's avatar
      md: make sure metadata is updated when spares are activated or removed. · 6dafab6b
      NeilBrown authored
      It isn't always necessary to update the metadata when spares are
      removed as the presence-or-not of a spare isn't really important to
      the integrity of an array.
      Also activating a spare doesn't always require updating the metadata
      as the update on 'recovery-completed' is usually sufficient.
      
      However the introduction of 'replacement' devices have made these
      transitions sometimes more important.  For example the 'Replacement'
      flag isn't cleared until the original device is removed, so we need
      to ensure a metadata update after that 'spare' is removed.
      
      So set MD_CHANGE_DEVS whenever a spare is activated or removed, to
      complement the current situation where it is set when a spare is added
      or a device is failed (or a number of other less common situations).
      
      This is suitable for -stable as out-of-data metadata could lead
      to data corruption.
      This is only relevant for 3.3 and later 9when 'replacement' as
      introduced.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      6dafab6b
    • NeilBrown's avatar
      md/raid5: fix calculate of 'degraded' when a replacement becomes active. · e5c86471
      NeilBrown authored
      When a replacement device becomes active, we mark the device that it
      replaces as 'faulty' so that it can subsequently get removed.
      However 'calc_degraded' only pays attention to the primary device, not
      the replacement, so the array appears to become degraded, which is
      wrong.
      
      So teach 'calc_degraded' to consider any replacement if a primary
      device is faulty.
      
      This is suitable for -stable as an incorrect 'degraded' value can
      confuse md and could lead to data corruption.
      This is only relevant for 3.3 and later.
      
      Cc: stable@vger.kernel.org
      Reported-by: default avatarRobin Hill <robin@robinhill.me.uk>
      Reported-by: default avatarJohn Drescher <drescherjm@gmail.com>
      Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      e5c86471
    • NeilBrown's avatar
      Revert "md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE." · a852d7b8
      NeilBrown authored
      This reverts commit 895e3c5c.
      
      While this patch seemed like a good idea and did help some workloads,
      it hurts other workloads.
      Large sequential O_DIRECT writes were faster,
      Small random O_DIRECT writes were slower.
      
      Other changes (batching RAID5 writes) have improved the sequential
      writes using a different mechanism, so the net result of this patch
      is definitely negative.  So revert it.
      Reported-by: default avatarShaohua Li <shli@kernel.org>
      Tested-by: default avatarJianpeng Ma <majianpeng@gmail.com>
      Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      a852d7b8
  3. 18 Sep, 2012 6 commits
  4. 17 Sep, 2012 10 commits
    • Linus Torvalds's avatar
      Merge branch 'for-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq · 4651afbb
      Linus Torvalds authored
      Pull another workqueue fix from Tejun Heo:
       "Unfortunately, yet another late fix.  This too is discovered and fixed
        by Lai.  This bug was introduced during this merge window by commit
        25511a47 ("workqueue: reimplement CPU online rebinding to handle
        idle workers") which started using WORKER_REBIND flag for idle rebind
        too.
      
        The bug is relatively easy to trigger if the CPU rapidly goes through
        off, on and then off (and stay off).  The fix is on the safer side.
        This hasn't been on linux-next yet but I'm pushing early so that it
        can get more exposure before v3.6 release."
      
      * 'for-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
        workqueue: always clear WORKER_REBIND in busy_worker_rebind_fn()
      4651afbb
    • Lai Jiangshan's avatar
      workqueue: always clear WORKER_REBIND in busy_worker_rebind_fn() · 960bd11b
      Lai Jiangshan authored
      busy_worker_rebind_fn() didn't clear WORKER_REBIND if rebinding failed
      (CPU is down again).  This used to be okay because the flag wasn't
      used for anything else.
      
      However, after 25511a47 "workqueue: reimplement CPU online rebinding
      to handle idle workers", WORKER_REBIND is also used to command idle
      workers to rebind.  If not cleared, the worker may confuse the next
      CPU_UP cycle by having REBIND spuriously set or oops / get stuck by
      prematurely calling idle_worker_rebind().
      
        WARNING: at /work/os/wq/kernel/workqueue.c:1323 worker_thread+0x4cd/0x5
       00()
        Hardware name: Bochs
        Modules linked in: test_wq(O-)
        Pid: 33, comm: kworker/1:1 Tainted: G           O 3.6.0-rc1-work+ #3
        Call Trace:
         [<ffffffff8109039f>] warn_slowpath_common+0x7f/0xc0
         [<ffffffff810903fa>] warn_slowpath_null+0x1a/0x20
         [<ffffffff810b3f1d>] worker_thread+0x4cd/0x500
         [<ffffffff810bc16e>] kthread+0xbe/0xd0
         [<ffffffff81bd2664>] kernel_thread_helper+0x4/0x10
        ---[ end trace e977cf20f4661968 ]---
        BUG: unable to handle kernel NULL pointer dereference at           (null)
        IP: [<ffffffff810b3db0>] worker_thread+0x360/0x500
        PGD 0
        Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
        Modules linked in: test_wq(O-)
        CPU 0
        Pid: 33, comm: kworker/1:1 Tainted: G        W  O 3.6.0-rc1-work+ #3 Bochs Bochs
        RIP: 0010:[<ffffffff810b3db0>]  [<ffffffff810b3db0>] worker_thread+0x360/0x500
        RSP: 0018:ffff88001e1c9de0  EFLAGS: 00010086
        RAX: 0000000000000000 RBX: ffff88001e633e00 RCX: 0000000000004140
        RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009
        RBP: ffff88001e1c9ea0 R08: 0000000000000000 R09: 0000000000000001
        R10: 0000000000000002 R11: 0000000000000000 R12: ffff88001fc8d580
        R13: ffff88001fc8d590 R14: ffff88001e633e20 R15: ffff88001e1c6900
        FS:  0000000000000000(0000) GS:ffff88001fc00000(0000) knlGS:0000000000000000
        CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
        CR2: 0000000000000000 CR3: 00000000130e8000 CR4: 00000000000006f0
        DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
        DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
        Process kworker/1:1 (pid: 33, threadinfo ffff88001e1c8000, task ffff88001e1c6900)
        Stack:
         ffff880000000000 ffff88001e1c9e40 0000000000000001 ffff88001e1c8010
         ffff88001e519c78 ffff88001e1c9e58 ffff88001e1c6900 ffff88001e1c6900
         ffff88001e1c6900 ffff88001e1c6900 ffff88001fc8d340 ffff88001fc8d340
        Call Trace:
         [<ffffffff810bc16e>] kthread+0xbe/0xd0
         [<ffffffff81bd2664>] kernel_thread_helper+0x4/0x10
        Code: b1 00 f6 43 48 02 0f 85 91 01 00 00 48 8b 43 38 48 89 df 48 8b 00 48 89 45 90 e8 ac f0 ff ff 3c 01 0f 85 60 01 00 00 48 8b 53 50 <8b> 02 83 e8 01 85 c0 89 02 0f 84 3b 01 00 00 48 8b 43 38 48 8b
        RIP  [<ffffffff810b3db0>] worker_thread+0x360/0x500
         RSP <ffff88001e1c9de0>
        CR2: 0000000000000000
      
      There was no reason to keep WORKER_REBIND on failure in the first
      place - WORKER_UNBOUND is guaranteed to be set in such cases
      preventing incorrectly activating concurrency management.  Always
      clear WORKER_REBIND.
      
      tj: Updated comment and description.
      Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      960bd11b
    • Linus Torvalds's avatar
      Merge branch 'akpm' (Andrew's patch-bomb) · 08077ca8
      Linus Torvalds authored
      Merge fixes from Andrew Morton:
       "13 patches.  12 are fixes and one is a little preparatory thing for
        Andi."
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (13 commits)
        memory hotplug: fix section info double registration bug
        mm/page_alloc: fix the page address of higher page's buddy calculation
        drivers/rtc/rtc-twl.c: ensure all interrupts are disabled during probe
        compiler.h: add __visible
        pid-namespace: limit value of ns_last_pid to (0, max_pid)
        include/net/sock.h: squelch compiler warning in sk_rmem_schedule()
        slub: consider pfmemalloc_match() in get_partial_node()
        slab: fix starting index for finding another object
        slab: do ClearSlabPfmemalloc() for all pages of slab
        nbd: clear waiting_queue on shutdown
        MAINTAINERS: fix TXT maintainer list and source repo path
        mm/ia64: fix a memory block size bug
        memory hotplug: reset pgdat->kswapd to NULL if creating kernel thread fails
      08077ca8
    • qiuxishi's avatar
      memory hotplug: fix section info double registration bug · f14851af
      qiuxishi authored
      There may be a bug when registering section info.  For example, on my
      Itanium platform, the pfn range of node0 includes the other nodes, so
      other nodes' section info will be double registered, and memmap's page
      count will equal to 3.
      
        node0: start_pfn=0x100,    spanned_pfn=0x20fb00, present_pfn=0x7f8a3, => 0x000100-0x20fc00
        node1: start_pfn=0x80000,  spanned_pfn=0x80000,  present_pfn=0x80000, => 0x080000-0x100000
        node2: start_pfn=0x100000, spanned_pfn=0x80000,  present_pfn=0x80000, => 0x100000-0x180000
        node3: start_pfn=0x180000, spanned_pfn=0x80000,  present_pfn=0x80000, => 0x180000-0x200000
      
        free_all_bootmem_node()
      	register_page_bootmem_info_node()
      		register_page_bootmem_info_section()
      
      When hot remove memory, we can't free the memmap's page because
      page_count() is 2 after put_page_bootmem().
      
        sparse_remove_one_section()
      	free_section_usemap()
      		free_map_bootmem()
      			put_page_bootmem()
      
      [akpm@linux-foundation.org: add code comment]
      Signed-off-by: default avatarXishi Qiu <qiuxishi@huawei.com>
      Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
      Acked-by: default avatarMel Gorman <mgorman@suse.de>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.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>
      f14851af
    • Li Haifeng's avatar
      mm/page_alloc: fix the page address of higher page's buddy calculation · 0ba8f2d5
      Li Haifeng authored
      The heuristic method for buddy has been introduced since commit
      43506fad ("mm/page_alloc.c: simplify calculation of combined index
      of adjacent buddy lists").  But the page address of higher page's buddy
      was wrongly calculated, which will lead page_is_buddy to fail for ever.
      IOW, the heuristic method would be disabled with the wrong page address
      of higher page's buddy.
      
      Calculating the page address of higher page's buddy should be based
      higher_page with the offset between index of higher page and index of
      higher page's buddy.
      Signed-off-by: default avatarHaifeng Li <omycle@gmail.com>
      Signed-off-by: default avatarGavin Shan <shangw@linux.vnet.ibm.com>
      Reviewed-by: default avatarMichal Hocko <mhocko@suse.cz>
      Cc: KyongHo Cho <pullip.cho@samsung.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Minchan Kim <minchan.kim@gmail.com>
      Cc: Johannes Weiner <jweiner@redhat.com>
      Cc: <stable@vger.kernel.org>	[2.6.38+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0ba8f2d5
    • Kevin Hilman's avatar
      drivers/rtc/rtc-twl.c: ensure all interrupts are disabled during probe · 8dcebaa9
      Kevin Hilman authored
      On some platforms, bootloaders are known to do some interesting RTC
      programming.  Without going into the obscurities as to why this may be
      the case, suffice it to say the the driver should not make any
      assumptions about the state of the RTC when the driver loads.  In
      particular, the driver probe should be sure that all interrupts are
      disabled until otherwise programmed.
      
      This was discovered when finding bursty I2C traffic every second on
      Overo platforms.  This I2C overhead was keeping the SoC from hitting
      deep power states.  The cause was found to be the RTC firing every
      second on the I2C-connected TWL PMIC.
      
      Special thanks to Felipe Balbi for suggesting to look for a rogue driver
      as the source of the I2C traffic rather than the I2C driver itself.
      
      Special thanks to Steve Sakoman for helping track down the source of the
      continuous RTC interrups on the Overo boards.
      Signed-off-by: default avatarKevin Hilman <khilman@ti.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Tested-by: default avatarSteve Sakoman <steve@sakoman.com>
      Cc: Alessandro Zummo <a.zummo@towertech.it>
      Tested-by: default avatarShubhrajyoti Datta <omaplinuxkernel@gmail.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>
      8dcebaa9
    • Andi Kleen's avatar
      compiler.h: add __visible · 9a858dc7
      Andi Kleen authored
      gcc 4.6+ has support for a externally_visible attribute that prevents the
      optimizer from optimizing unused symbols away.  Add a __visible macro to
      use it with that compiler version or later.
      
      This is used (at least) by the "Link Time Optimization" patchset.
      Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9a858dc7
    • Andrew Vagin's avatar
      pid-namespace: limit value of ns_last_pid to (0, max_pid) · 579035dc
      Andrew Vagin authored
      The kernel doesn't check the pid for negative values, so if you try to
      write -2 to /proc/sys/kernel/ns_last_pid, you will get a kernel panic.
      
      The crash happens because the next pid is -1, and alloc_pidmap() will
      try to access to a nonexistent pidmap.
      
        map = &pid_ns->pidmap[pid/BITS_PER_PAGE];
      Signed-off-by: default avatarAndrew Vagin <avagin@openvz.org>
      Acked-by: default avatarCyrill Gorcunov <gorcunov@openvz.org>
      Acked-by: default avatarOleg Nesterov <oleg@redhat.com>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      579035dc
    • Chuck Lever's avatar
      include/net/sock.h: squelch compiler warning in sk_rmem_schedule() · 35c448a8
      Chuck Lever authored
      This warning:
      
        In file included from linux/include/linux/tcp.h:227:0,
                         from linux/include/linux/ipv6.h:221,
                         from linux/include/net/ipv6.h:16,
                         from linux/include/linux/sunrpc/clnt.h:26,
                         from linux/net/sunrpc/stats.c:22:
        linux/include/net/sock.h: In function `sk_rmem_schedule':
        linux/nfs-2.6/include/net/sock.h:1339:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      
      is seen with gcc (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2) using the
      -Wextra option.
      
      Commit c76562b6 ("netvm: prevent a stream-specific deadlock")
      accidentally replaced the "size" parameter of sk_rmem_schedule() with an
      unsigned int.  This changes the semantics of the comparison in the
      return statement.
      
      In sk_wmem_schedule we have syntactically the same comparison, but
      "size" is a signed integer.  In addition, __sk_mem_schedule() takes a
      signed integer for its "size" parameter, so there is an implicit type
      conversion in sk_rmem_schedule() anyway.
      
      Revert the "size" parameter back to a signed integer so that the
      semantics of the expressions in both sk_[rw]mem_schedule() are exactly
      the same.
      Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Cc: David Miller <davem@davemloft.net>
      Cc: Joonsoo Kim <js1304@gmail.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      35c448a8
    • Joonsoo Kim's avatar
      slub: consider pfmemalloc_match() in get_partial_node() · 8ba00bb6
      Joonsoo Kim authored
      get_partial() is currently not checking pfmemalloc_match() meaning that
      it is possible for pfmemalloc pages to leak to non-pfmemalloc users.
      This is a problem in the following situation.  Assume that there is a
      request from normal allocation and there are no objects in the per-cpu
      cache and no node-partial slab.
      
      In this case, slab_alloc enters the slow path and new_slab_objects() is
      called which may return a PFMEMALLOC page.  As the current user is not
      allowed to access PFMEMALLOC page, deactivate_slab() is called
      ([5091b74a: mm: slub: optimise the SLUB fast path to avoid pfmemalloc
      checks]) and returns an object from PFMEMALLOC page.
      
      Next time, when we get another request from normal allocation,
      slab_alloc() enters the slow-path and calls new_slab_objects().  In
      new_slab_objects(), we call get_partial() and get a partial slab which
      was just deactivated but is a pfmemalloc page.  We extract one object
      from it and re-deactivate.
      
        "deactivate -> re-get in get_partial -> re-deactivate" occures repeatedly.
      
      As a result, access to PFMEMALLOC page is not properly restricted and it
      can cause a performance degradation due to frequent deactivation.
      deactivation frequently.
      
      This patch changes get_partial_node() to take pfmemalloc_match() into
      account and prevents the "deactivate -> re-get in get_partial()
      scenario.  Instead, new_slab() is called.
      Signed-off-by: default avatarJoonsoo Kim <js1304@gmail.com>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Cc: David Miller <davem@davemloft.net>
      Cc: Chuck Lever <chuck.lever@oracle.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8ba00bb6