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  1. 04 Dec, 2012 2 commits
    • Tejun Heo's avatar
      workqueue: convert BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s · fc4b514f
      Tejun Heo authored 
      8852aac2 ("workqueue: mod_delayed_work_on() shouldn't queue timer on
0 delay") unexpectedly uncovered a very nasty abuse of delayed_work in
megaraid - it allocated work_struct, casted it to delayed_work and
then pass that into queue_delayed_work().

Previously, this was okay because 0 @delay short-circuited to
queue_work() before doing anything with delayed_work.  8852aac2
moved 0 @delay test into __queue_delayed_work() after sanity check on
delayed_work making megaraid trigger BUG_ON().

Although megaraid is already fixed by c1d390d8 ("megaraid: fix
BUG_ON() from incorrect use of delayed work"), this patch converts
BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s so that such
abusers, if there are more, trigger warning but don't crash the
machine.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Xiaotian Feng <xtfeng@gmail.com>
      fc4b514f
    • Xiaotian Feng's avatar
      megaraid: fix BUG_ON() from incorrect use of delayed work · c1d390d8
      Xiaotian Feng authored 
      megaraid use INIT_WORK to declare a hotplug_work, but cast the
hotplug_work from work_struct to delayed_work and
schedule_delayed_work on it.  This is very dangerous, as other part of
delayed_work might be kernel memories allocated by others.

With commit 8852aac2 ("workqueue: mod_delayed_work_on() shouldn't queue
timer on 0 delay"), schedule_delayed_work() will check dwork->timer
before queue_work even when @delay is 0, this causes megaraid code to
hit the BUG_ON() in workqueue code.  Change megaraid code to use
delayed work.
Signed-off-by: default avatarXiaotian Feng <dannyfeng@tencent.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Neela Syam Kolli <megaraidlinux@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: linux-scsi@vger.kernel.org
      c1d390d8
  3. 02 Dec, 2012 1 commit
    • Tejun Heo's avatar
      workqueue: mod_delayed_work_on() shouldn't queue timer on 0 delay · 8852aac2
      Tejun Heo authored 
      8376fe22 ("workqueue: implement mod_delayed_work[_on]()")
implemented mod_delayed_work[_on]() using the improved
try_to_grab_pending().  The function is later used, among others, to
replace [__]candel_delayed_work() + queue_delayed_work() combinations.

Unfortunately, a delayed_work item w/ zero @delay is handled slightly
differently by mod_delayed_work_on() compared to
queue_delayed_work_on().  The latter skips timer altogether and
directly queues it using queue_work_on() while the former schedules
timer which will expire on the closest tick.  This means, when @delay
is zero, that [__]cancel_delayed_work() + queue_delayed_work_on()
makes the target item immediately executable while
mod_delayed_work_on() may induce delay of upto a full tick.

This somewhat subtle difference breaks some of the converted users.
e.g. block queue plugging uses delayed_work for deferred processing
and uses mod_delayed_work_on() when the queue needs to be immediately
unplugged.  The above problem manifested as noticeably higher number
of context switches under certain circumstances.

The difference in behavior was caused by missing special case handling
for 0 delay in mod_delayed_work_on() compared to
queue_delayed_work_on().  Joonsoo Kim posted a patch to add it -
("workqueue: optimize mod_delayed_work_on() when @delay == 0")[1].
The patch was queued for 3.8 but it was described as optimization and
I missed that it was a correctness issue.

As both queue_delayed_work_on() and mod_delayed_work_on() use
__queue_delayed_work() for queueing, it seems that the better approach
is to move the 0 delay special handling to the function instead of
duplicating it in mod_delayed_work_on().

Fix the problem by moving 0 delay special case handling from
queue_delayed_work_on() to __queue_delayed_work().  This replaces
Joonsoo's patch.

[1] http://thread.gmane.org/gmane.linux.kernel/1379011/focus=1379012Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reported-and-tested-by: default avatarAnders Kaseorg <andersk@MIT.EDU>
Reported-and-tested-by: default avatarZlatko Calusic <zlatko.calusic@iskon.hr>
LKML-Reference: <alpine.DEB.2.00.1211280953350.26602@dr-wily.mit.edu>
LKML-Reference: <50A78AA9.5040904@iskon.hr>
Cc: Joonsoo Kim <js1304@gmail.com>
      8852aac2
  5. 01 Dec, 2012 10 commits
  7. 30 Nov, 2012 13 commits
    • Vincent Palatin's avatar
      x86, fpu: Avoid FPU lazy restore after suspend · 644c1541
      Vincent Palatin authored 
      When a cpu enters S3 state, the FPU state is lost.
After resuming for S3, if we try to lazy restore the FPU for a process running
on the same CPU, this will result in a corrupted FPU context.

Ensure that "fpu_owner_task" is properly invalided when (re-)initializing a CPU,
so nobody will try to lazy restore a state which doesn't exist in the hardware.

Tested with a 64-bit kernel on a 4-core Ivybridge CPU with eagerfpu=off,
by doing thousands of suspend/resume cycles with 4 processes doing FPU
operations running. Without the patch, a process is killed after a
few hundreds cycles by a SIGFPE.

Cc: Duncan Laurie <dlaurie@chromium.org>
Cc: Olof Johansson <olofj@chromium.org>
Cc: <stable@kernel.org> v3.4+ # for 3.4 need to replace this_cpu_write by percpu_write
Signed-off-by: default avatarVincent Palatin <vpalatin@chromium.org>
Link: http://lkml.kernel.org/r/1354306532-1014-1-git-send-email-vpalatin@chromium.orgSigned-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
      644c1541
    • Linus Torvalds's avatar
      Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux · cc19528b
      Linus Torvalds authored 
      Pull DRM fixes from Dave Airlie:
 "Just driver fixes, nothing major, except maybe the Ironlake rc6
  disable:

   - intel:
     * revert ironlake rc6 - we still have one ilk regression, but this
       gets rid of one big one
     * turn off cloning
     * a directed fix for Apple edp
   - radeon: one modesetting fix
   - exynos: minor fixes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  radeon: fix pll/ctrc mapping on dce2 and dce3 hardware
  Revert "drm/i915: enable rc6 on ilk again"
  drm/i915: do not default to 18 bpp for eDP if missing from VBT
  drm/exynos: Fix potential NULL pointer dereference in exynos_drm_encoder.c
  drm/exynos: Make exynos4/5_fimd_driver_data static
  drm/exynos: fix overlay updating issue
  drm/exynos: remove unnecessary code.
  drm/exynos: fix linux framebuffer address setting.
  drm/i915: disable cloning on sdvo
      cc19528b
    • Linus Torvalds's avatar
      Merge branch 'akpm' (Fixes from Andrew) · 50a53bbe
      Linus Torvalds authored 
      Merge misc fixes from Andrew Morton:
 "Seven fixes, some of them fingers-crossed :("

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (7 patches)
  drivers/rtc/rtc-tps65910.c: fix invalid pointer access on _remove()
  mm: soft offline: split thp at the beginning of soft_offline_page()
  mm: avoid waking kswapd for THP allocations when compaction is deferred or contended
  revert "Revert "mm: remove __GFP_NO_KSWAPD""
  mm: vmscan: fix endless loop in kswapd balancing
  mm/vmemmap: fix wrong use of virt_to_page
  mm: compaction: fix return value of capture_free_page()
      50a53bbe
    • Linus Torvalds's avatar
      Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc · 73efd00d
      Linus Torvalds authored 
      Pull ARM SoC fixes from Arnd Bergmann:
 "These are three fixes for the Marvell EBU family and one for the
  Samsung s3c platforms.  All of them are obvious should still make it
  into 3.7."

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: Kirkwood: Update PCI-E fixup
  Dove: Fix irq_to_pmu()
  Dove: Attempt to fix PMU/RTC interrupts
  ARM: S3C24XX: Fix potential NULL pointer dereference error
      73efd00d
    • Linus Torvalds's avatar
      Merge tag 'ixp4xx-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc · 90bf80a1
      Linus Torvalds authored 
      Pull ARM ixp4xx bug fixes from Arnd Bergmann:
 "These were originally prepared by Krzysztof Halasa but not submitted
  in time for v3.7 due to some confusion about how ixp4xx patches should
  be handled.  Jason Cooper thankfully offered to help out sending the
  patches upstream through arm-soc now, but given the timing, we could
  as well delay them for 3.8."

* tag 'ixp4xx-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  IXP4xx: use __iomem for MMIO
  IXP4xx: map CPU config registers within VMALLOC region.
  IXP4xx: Always ioremap() Queue Manager MMIO region at boot.
  ixp4xx: Declare MODULE_FIRMWARE usage
  IXP4xx crypto: MOD_AES{128,192,256} already include key size.
  WAN: Remove redundant HDLC info printed by IXP4xx HSS driver.
  IXP4xx: Remove time limit for PCI TRDY to enable use of slow devices.
  IXP4xx: ixp4xx_crypto driver requires Queue Manager and NPE drivers.
  IXP4xx: HW pseudo-random generator is available on IXP45x/46x only.
  IXP4xx: Fix off-by-one bug in Goramo MultiLink platform.
  IXP4xx: Fix Goramo MultiLink platform compilation.
      90bf80a1
    • Linus Torvalds's avatar
      Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm · 50a561ca
      Linus Torvalds authored 
      Pull final ARM fix from Russell King:
 "One final fix, spotted by Will, to do with what happens when we boot a
  SMP kernel on UP."

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7586/1: sp804: set cpumask to cpu_possible_mask for clock event device
      50a561ca
    • Kim, Milo's avatar
      drivers/rtc/rtc-tps65910.c: fix invalid pointer access on _remove() · 1430e178
      Kim, Milo authored 
      The tps65910_rtc data is registered as the platform driver data in
_probe(= ).  Therefore the tps65910_rtc should be used on unregistering
the rtc device.  And device pointer should be retrieved from the
platform_device structure.

This patch fixes the below oops:

 Unable to handle kernel NULL pointer dereference at virtual address 00000008
 Modules linked in: rtc_tps65910(-)
 CPU: 0    Not tainted  (3.7.0-rc7-next-20121128-g6b1f974-dirty #7)
 PC is at tps65910_rtc_alarm_irq_enable+0x20/0x2c [rtc_tps65910]
     (tps65910_rtc_alarm_irq_enable+0x20/0x2c [rtc_tps65910])
     (tps65910_rtc_remove+0x18/0x28 [rtc_tps65910])
     (platform_drv_remove+0x18/0x1c)
     (__device_release_driver+0x70/0xcc)
     (driver_detach+0xb4/0xb8)
     (bus_remove_driver+0x7c/0xc0)
     (sys_delete_module+0x148/0x21c)
Signed-off-by: default avatarMilo(Woogyom) Kim <milo.kim@ti.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>
      1430e178
    • Naoya Horiguchi's avatar
      mm: soft offline: split thp at the beginning of soft_offline_page() · 783657a7
      Naoya Horiguchi authored 
      When we try to soft-offline a thp tail page, put_page() is called on the
tail page unthinkingly and VM_BUG_ON is triggered in put_compound_page().

This patch splits thp before going into the main body of soft-offlining.
Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.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>
      783657a7
    • Mel Gorman's avatar
      mm: avoid waking kswapd for THP allocations when compaction is deferred or contended · 782fd304
      Mel Gorman authored 
      With "mm: vmscan: scale number of pages reclaimed by reclaim/compaction
based on failures" reverted, Zdenek Kabelac reported the following

  Hmm,  so it's just took longer to hit the problem and observe
  kswapd0 spinning on my CPU again - it's not as endless like before -
  but still it easily eats minutes - it helps to turn off  Firefox
  or TB  (memory hungry apps) so kswapd0 stops soon - and restart
  those apps again.  (And I still have like >1GB of cached memory)

  kswapd0         R  running task        0    30      2 0x00000000
  Call Trace:
    preempt_schedule+0x42/0x60
    _raw_spin_unlock+0x55/0x60
    put_super+0x31/0x40
    drop_super+0x22/0x30
    prune_super+0x149/0x1b0
    shrink_slab+0xba/0x510

The sysrq+m indicates the system has no swap so it'll never reclaim
anonymous pages as part of reclaim/compaction.  That is one part of the
problem but not the root cause as file-backed pages could also be
reclaimed.

The likely underlying problem is that kswapd is woken up or kept awake
for each THP allocation request in the page allocator slow path.

If compaction fails for the requesting process then compaction will be
deferred for a time and direct reclaim is avoided.  However, if there
are a storm of THP requests that are simply rejected, it will still be
the the case that kswapd is awake for a prolonged period of time as
pgdat->kswapd_max_order is updated each time.  This is noticed by the
main kswapd() loop and it will not call kswapd_try_to_sleep().  Instead
it will loopp, shrinking a small number of pages and calling
shrink_slab() on each iteration.

This patch defers when kswapd gets woken up for THP allocations.  For
!THP allocations, kswapd is always woken up.  For THP allocations,
kswapd is woken up iff the process is willing to enter into direct
reclaim/compaction.

[akpm@linux-foundation.org: fix typo in comment]
Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
Cc: Zdenek Kabelac <zkabelac@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      782fd304
    • Andrew Morton's avatar
      revert "Revert "mm: remove __GFP_NO_KSWAPD"" · a5091539
      Andrew Morton authored 
      It apepars that this patch was innocent, and we hope that "mm: avoid
waking kswapd for THP allocations when compaction is deferred or
contended" will fix the final kswapd-spinning cause.

Cc: Zdenek Kabelac <zkabelac@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a5091539
    • Johannes Weiner's avatar
      mm: vmscan: fix endless loop in kswapd balancing · 60cefed4
      Johannes Weiner authored 
      Kswapd does not in all places have the same criteria for a balanced
zone.  Zones are only being reclaimed when their high watermark is
breached, but compaction checks loop over the zonelist again when the
zone does not meet the low watermark plus two times the size of the
allocation.  This gets kswapd stuck in an endless loop over a small
zone, like the DMA zone, where the high watermark is smaller than the
compaction requirement.

Add a function, zone_balanced(), that checks the watermark, and, for
higher order allocations, if compaction has enough free memory.  Then
use it uniformly to check for balanced zones.

This makes sure that when the compaction watermark is not met, at least
reclaim happens and progress is made - or the zone is declared
unreclaimable at some point and skipped entirely.
Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Reported-by: default avatarGeorge Spelvin <linux@horizon.com>
Reported-by: default avatarJohannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
Reported-by: default avatarTomas Racek <tracek@redhat.com>
Tested-by: default avatarJohannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
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>
      60cefed4
    • Jianguo Wu's avatar
      mm/vmemmap: fix wrong use of virt_to_page · ae64ffca
      Jianguo Wu authored 
      I enable CONFIG_DEBUG_VIRTUAL and CONFIG_SPARSEMEM_VMEMMAP, when doing
memory hotremove, there is a kernel BUG at arch/x86/mm/physaddr.c:20.

It is caused by free_section_usemap()->virt_to_page(), virt_to_page() is
only used for kernel direct mapping address, but sparse-vmemmap uses
vmemmap address, so it is going wrong here.

  ------------[ cut here ]------------
  kernel BUG at arch/x86/mm/physaddr.c:20!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: acpihp_drv acpihp_slot edd cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf fuse vfat fat loop dm_mod coretemp kvm crc32c_intel ipv6 ixgbe igb iTCO_wdt i7core_edac edac_core pcspkr iTCO_vendor_support ioatdma microcode joydev sr_mod i2c_i801 dca lpc_ich mfd_core mdio tpm_tis i2c_core hid_generic tpm cdrom sg tpm_bios rtc_cmos button ext3 jbd mbcache usbhid hid uhci_hcd ehci_hcd usbcore usb_common sd_mod crc_t10dif processor thermal_sys hwmon scsi_dh_alua scsi_dh_hp_sw scsi_dh_rdac scsi_dh_emc scsi_dh ata_generic ata_piix libata megaraid_sas scsi_mod
  CPU 39
  Pid: 6454, comm: sh Not tainted 3.7.0-rc1-acpihp-final+ #45 QCI QSSC-S4R/QSSC-S4R
  RIP: 0010:[<ffffffff8103c908>]  [<ffffffff8103c908>] __phys_addr+0x88/0x90
  RSP: 0018:ffff8804440d7c08  EFLAGS: 00010006
  RAX: 0000000000000006 RBX: ffffea0012000000 RCX: 000000000000002c
  ...
Signed-off-by: default avatarJianguo Wu <wujianguo@huawei.com>
Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
Reviewd-by: default avatarWen Congyang <wency@cn.fujitsu.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: default avatarMichal Hocko <mhocko@suse.cz>
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>
      ae64ffca
    • Mel Gorman's avatar
      mm: compaction: fix return value of capture_free_page() · 58d00209
      Mel Gorman authored 
      Commit ef6c5be6 ("fix incorrect NR_FREE_PAGES accounting (appears
like memory leak)") fixes a NR_FREE_PAGE accounting leak but missed the
return value which was also missed by this reviewer until today.

That return value is used by compaction when adding pages to a list of
isolated free pages and without this follow-up fix, there is a risk of
free list corruption.
Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      58d00209
  9. 29 Nov, 2012 8 commits
  11. 28 Nov, 2012 6 commits
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