8852aac25e ("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. 8852aac25e
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 c1d390d8e6 ("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: Tejun Heo <tj@kernel.org>
Cc: Xiaotian Feng <xtfeng@gmail.com>
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 8852aac ("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: Xiaotian Feng <dannyfeng@tencent.com>
Signed-off-by: Tejun 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
8376fe22c7 ("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=1379012
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Anders Kaseorg <andersk@MIT.EDU>
Reported-and-tested-by: Zlatko 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>
A rescue thread exiting TASK_INTERRUPTIBLE can lead to a task scheduling
off, never to be seen again. In the case where this occurred, an exiting
thread hit reiserfs homebrew conditional resched while holding a mutex,
bringing the box to its knees.
PID: 18105 TASK: ffff8807fd412180 CPU: 5 COMMAND: "kdmflush"
#0 [ffff8808157e7670] schedule at ffffffff8143f489
#1 [ffff8808157e77b8] reiserfs_get_block at ffffffffa038ab2d [reiserfs]
#2 [ffff8808157e79a8] __block_write_begin at ffffffff8117fb14
#3 [ffff8808157e7a98] reiserfs_write_begin at ffffffffa0388695 [reiserfs]
#4 [ffff8808157e7ad8] generic_perform_write at ffffffff810ee9e2
#5 [ffff8808157e7b58] generic_file_buffered_write at ffffffff810eeb41
#6 [ffff8808157e7ba8] __generic_file_aio_write at ffffffff810f1a3a
#7 [ffff8808157e7c58] generic_file_aio_write at ffffffff810f1c88
#8 [ffff8808157e7cc8] do_sync_write at ffffffff8114f850
#9 [ffff8808157e7dd8] do_acct_process at ffffffff810a268f
[exception RIP: kernel_thread_helper]
RIP: ffffffff8144a5c0 RSP: ffff8808157e7f58 RFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8107af60 RDI: ffff8803ee491d18
RBP: 0000000000000000 R8: 0000000000000000 R9: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Pull RCU fix from Ingo Molnar:
"Fix leaking RCU extended quiescent state, which might trigger warnings
and mess up the extended quiescent state tracking logic into thinking
that we are in "RCU user mode" while we aren't."
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rcu: Fix unrecovered RCU user mode in syscall_trace_leave()
Pull perf fixes from Ingo Molnar:
"This is mostly about unbreaking architectures that took the UAPI
changes in the v3.7 cycle, plus misc fixes."
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf kvm: Fix building perf kvm on non x86 arches
perf kvm: Rename perf_kvm to perf_kvm_stat
perf: Make perf build for x86 with UAPI disintegration applied
perf powerpc: Use uapi/unistd.h to fix build error
tools: Pass the target in descend
tools: Honour the O= flag when tool build called from a higher Makefile
tools: Define a Makefile function to do subdir processing
x86: Export asm/{svm.h,vmx.h,perf_regs.h}
perf tools: Fix strbuf_addf() when the buffer needs to grow
perf header: Fix numa topology printing
perf, powerpc: Fix hw breakpoints returning -ENOSPC
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
- Don't build 'perf kvm stat" on non-x86 arches, fix from Xiao Guangrong.
- UAPI fixes to get perf building again in non-x86 arches, from David Howells.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Peter Anvin.
This includes the resume-time FPU corruption fix from the chromeos guys,
marked for stable.
* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, fpu: Avoid FPU lazy restore after suspend
x86-32: Unbreak booting on some 486 clones
x86, kvm: Remove incorrect redundant assembly constraint
Pull C6X fixes from Mark Salter.
* tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming:
c6x: use generic kvm_para.h
c6x: remove internal kernel symbols from exported setup.h
c6x: fix misleading comment
c6x: run do_notify_resume with interrupts enabled
Pull assorted signal-related fixes from Al Viro:
"uml regression fix (braino in sys_execve() patch) + a bunch of fucked
sigaltstack-on-rt_sigreturn uses, similar to sparc64 fix that went in
through davem's tree. m32r horrors not included - that one's waiting
for maintainer."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
microblaze: rt_sigreturn is too trigger-happy about sigaltstack errors
score: do_sigaltstack() expects a userland pointer...
sh64: fix altstack switching on sigreturn
openrisk: fix altstack switching on sigreturn
um: get_safe_registers() should be done in flush_thread(), not start_thread()
Pull CIFS fixes from Steve French:
"Two low risk, small fixes, that fix cifs regressions introduced in
3.7."
* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
CIFS: Fix wrong buffer pointer usage in smb_set_file_info
cifs: fix writeback race with file that is growing
Pull remoteproc fix from Ohad Ben-Cohen:
"A single remoteproc fix for an error path issue reported by Ido Yariv."
* tag 'rproc-3.7-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc:
remoteproc: fix error path of ->find_vqs
Pull target fix from Nicholas Bellinger:
"So just a single target fix for v3.7.0 this time around from Roland to
address a aborted command bug w/ tcm_qla2xxx fabric ports.
Also, there is one outstanding IBLOCK + virtio-blk bug that is still
being tracked down effecting v3.6.x, but AFAICT thus far this appears
to be a bug outside of target code."
* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
target: Fix handling of aborted commands
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: Vincent Palatin <vpalatin@chromium.org>
Link: http://lkml.kernel.org/r/1354306532-1014-1-git-send-email-vpalatin@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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
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()
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
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.
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
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: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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: Mel 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: George Spelvin <linux@horizon.com>
Reported-by: Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
Reported-by: Tomas Racek <tracek@redhat.com>
Tested-by: Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tejun Heo
Xiaotian Feng
Mike Galbraith
Linus Torvalds
Ingo Molnar
Vincent Palatin
Kim, Milo
Naoya Horiguchi
Mel Gorman
Andrew Morton
Johannes Weiner
Jianguo Wu