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Vlastimil Babka a9f2a846f0 mm, slab: reschedule cache_reap() on the same CPU
cache_reap() is initially scheduled in start_cpu_timer() via
schedule_delayed_work_on(). But then the next iterations are scheduled
via schedule_delayed_work(), i.e. using WORK_CPU_UNBOUND.

Thus since commit ef55718044 ("workqueue: schedule WORK_CPU_UNBOUND
work on wq_unbound_cpumask CPUs") there is no guarantee the future
iterations will run on the originally intended cpu, although it's still
preferred.  I was able to demonstrate this with
/sys/module/workqueue/parameters/debug_force_rr_cpu.  IIUC, it may also
happen due to migrating timers in nohz context.  As a result, some cpu's
would be calling cache_reap() more frequently and others never.

This patch uses schedule_delayed_work_on() with the current cpu when
scheduling the next iteration.

Link: http://lkml.kernel.org/r/20180411070007.32225-1-vbabka@suse.cz
Fixes: ef55718044 ("workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-13 17:10:27 -07:00
arch mm/gup.c: document return value 2018-04-13 17:10:27 -07:00
block for-4.17/block-20180402 2018-04-05 14:27:02 -07:00
certs
crypto MIPS changes for 4.17 2018-04-10 11:39:22 -07:00
Documentation We decided to request the latest three patches to be merged into this 2018-04-12 13:00:44 -07:00
drivers amdgpu, omap and snd regression fix 2018-04-12 20:56:10 -07:00
firmware
fs Changes since last update: 2018-04-12 13:28:22 -07:00
include Merge branch 'parisc-4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2018-04-12 17:07:04 -07:00
init seq_file: allocate seq_file from kmem_cache 2018-04-11 10:28:36 -07:00
ipc ipc/shm: fix use-after-free of shm file via remap_file_pages() 2018-04-13 17:10:27 -07:00
kernel kexec: export PG_swapbacked to VMCOREINFO 2018-04-13 17:10:27 -07:00
lib We decided to request the latest three patches to be merged into this 2018-04-12 13:00:44 -07:00
LICENSES
mm mm, slab: reschedule cache_reap() on the same CPU 2018-04-13 17:10:27 -07:00
net NFS client updates for Linux 4.17 2018-04-12 12:55:50 -07:00
samples remoteproc updates for v4.17 2018-04-10 12:09:27 -07:00
scripts asm-generic fixes for v4.17-rc1 2018-04-12 09:15:48 -07:00
security ipc/msg: introduce msgctl(MSG_STAT_ANY) 2018-04-11 10:28:37 -07:00
sound amdgpu, omap and snd regression fix 2018-04-12 20:56:10 -07:00
tools proc: fixup copyright sign 2018-04-12 20:52:25 -07:00
usr
virt
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.mailmap Merge candidates for 4.17 merge window 2018-04-06 17:35:43 -07:00
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS ARM: SoC fixes for 4.17 2018-04-11 16:12:21 -07:00
Makefile
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.