Tejun Heo
041bd12e27
Revert "workqueue: make sure delayed work run in local cpu"
...
This reverts commit 874bbfe600 .
Workqueue used to implicity guarantee that work items queued without
explicit CPU specified are put on the local CPU. Recent changes in
timer broke the guarantee and led to vmstat breakage which was fixed
by 176bed1de5 ("vmstat: explicitly schedule per-cpu work on the CPU
we need it to run on").
vmstat is the most likely to expose the issue and it's quite possible
that there are other similar problems which are a lot more difficult
to trigger. As a preventive measure, 874bbfe600 ("workqueue: make
sure delayed work run in local cpu") was applied to restore the local
CPU guarnatee. Unfortunately, the change exposed a bug in timer code
which got fixed by 22b886dd10 ("timers: Use proper base migration in
add_timer_on()"). Due to code restructuring, the commit couldn't be
backported beyond certain point and stable kernels which only had
874bbfe600 started crashing.
The local CPU guarantee was accidental more than anything else and we
want to get rid of it anyway. As, with the vmstat case fixed,
874bbfe600 is causing more problems than it's fixing, it has been
decided to take the chance and officially break the guarantee by
reverting the commit. A debug feature will be added to force foreign
CPU assignment to expose cases relying on the guarantee and fixes for
the individual cases will be backported to stable as necessary.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 874bbfe600 ("workqueue: make sure delayed work run in local cpu")
Link: http://lkml.kernel.org/g/20160120211926.GJ10810@quack.suse.cz
Cc: stable@vger.kernel.org
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Daniel Bilik <daniel.bilik@neosystem.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shli@fb.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Bilik <daniel.bilik@neosystem.cz>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
2016-02-09 16:11:26 -05:00
..
bpf
net: bpf: reject invalid shifts
2016-01-12 17:06:53 -05:00
configs
debug
module: use a structure to encapsulate layout.
2015-12-04 22:46:25 +01:00
events
wrappers for ->i_mutex access
2016-01-22 18:04:28 -05:00
gcov
gcov: use within_module() helper.
2015-12-04 22:46:25 +01:00
irq
PCI changes for the v4.5 merge window:
2016-01-21 11:52:16 -08:00
livepatch
livepatch: Cleanup module page permission changes
2015-12-04 22:51:07 +01:00
locking
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-01-11 14:18:38 -08:00
power
PM / sleep: Add support for read-only sysfs attributes
2016-01-04 22:28:59 +01:00
printk
kernel: printk: specify alignment for struct printk_log
2016-01-20 17:09:18 -08:00
rcu
Merge branches 'doc.2015.12.05a', 'exp.2015.12.07a', 'fixes.2015.12.07a', 'list.2015.12.04b' and 'torture.2015.12.05a' into HEAD
2015-12-07 17:02:54 -08:00
sched
wrappers for ->i_mutex access
2016-01-22 18:04:28 -05:00
time
Merge branch 'pm-cpuidle'
2016-01-21 00:43:21 +01:00
trace
Not much new with tracing for this release. Mostly just clean ups and
2016-01-12 20:04:15 -08:00
.gitignore
certs: add .gitignore to stop git nagging about x509_certificate_list
2015-10-21 15:18:35 +01:00
acct.c
async.c
async: export current_is_async()
2015-11-19 17:51:48 +01:00
audit.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2016-01-17 19:13:15 -08:00
audit.h
security: Make inode argument of inode_getsecid non-const
2015-12-24 11:09:39 -05:00
audit_fsnotify.c
wrappers for ->i_mutex access
2016-01-22 18:04:28 -05:00
audit_tree.c
audit: audit_tree_match can be boolean
2015-11-04 08:23:51 -05:00
audit_watch.c
wrappers for ->i_mutex access
2016-01-22 18:04:28 -05:00
auditfilter.c
audit: fix comment block whitespace
2015-11-04 08:23:51 -05:00
auditsc.c
security: Make inode argument of inode_getsecid non-const
2015-12-24 11:09:39 -05:00
backtracetest.c
bounds.c
capability.c
cgroup.c
Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2016-01-12 19:20:32 -08:00
cgroup_freezer.c
cgroup: kill cgrp_ss_priv[CGROUP_CANFORK_COUNT] and friends
2015-12-03 10:24:08 -05:00
cgroup_pids.c
cgroup_pids: fix a typo.
2015-12-14 14:54:37 -05:00
compat.c
configs.c
context_tracking.c
context_tracking: Switch to new static_branch API
2015-11-24 09:56:43 +01:00
cpu.c
kernel/cpu.c: make set_cpu_* static inlines
2016-01-20 17:09:18 -08:00
cpu_pm.c
cpuset.c
Merge branch 'for-4.4-fixes' into for-4.5
2015-12-03 10:22:52 -05:00
crash_dump.c
cred.c
kmemcg: account certain kmem allocations to memcg
2016-01-14 16:00:49 -08:00
delayacct.c
kmemcg: account certain kmem allocations to memcg
2016-01-14 16:00:49 -08:00
dma.c
elfcore.c
exec_domain.c
exit.c
exit: remove unneeded declaration of exit_mm()
2016-01-20 17:09:18 -08:00
extable.c
fork.c
mm: rework virtual memory accounting
2016-01-14 16:00:49 -08:00
freezer.c
futex.c
ptrace: use fsuid, fsgid, effective creds for fs access checks
2016-01-20 17:09:18 -08:00
futex_compat.c
ptrace: use fsuid, fsgid, effective creds for fs access checks
2016-01-20 17:09:18 -08:00
groups.c
hung_task.c
irq_work.c
treewide: Remove old email address
2015-11-23 09:44:58 +01:00
jump_label.c
treewide: Remove old email address
2015-11-23 09:44:58 +01:00
kallsyms.c
kcmp.c
ptrace: use fsuid, fsgid, effective creds for fs access checks
2016-01-20 17:09:18 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c
kexec: set KEXEC_TYPE_CRASH before sanity_check_segment_list()
2016-01-20 17:09:18 -08:00
kexec_core.c
kernel/kexec_core.c: use list_for_each_entry_safe in kimage_free_page_list
2016-01-20 17:09:18 -08:00
kexec_file.c
kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE
2016-01-20 17:09:18 -08:00
kexec_internal.h
kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE
2016-01-20 17:09:18 -08:00
kmod.c
kmod: don't run async usermode helper as a child of kworker thread
2015-10-23 17:55:10 +09:00
kprobes.c
ksysfs.c
rcu: Remove TINY_RCU bloat from pointless boot parameters
2015-12-07 16:59:37 -08:00
kthread.c
latencytop.c
Makefile
membarrier.c
memremap.c
mm, x86: get_user_pages() for dax mappings
2016-01-15 17:56:32 -08:00
module-internal.h
module.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
2016-01-14 16:38:02 -08:00
module_signing.c
KEYS: Merge the type-specific data with the payload data
2015-10-21 15:18:36 +01:00
notifier.c
nsproxy.c
padata.c
panic.c
printk: do cond_resched() between lines while outputting to consoles
2016-01-16 11:17:25 -08:00
params.c
Nothing exciting, minor tweaks and cleanups.
2015-11-09 15:53:39 -08:00
pid.c
kmemcg: account certain kmem allocations to memcg
2016-01-14 16:00:49 -08:00
pid_namespace.c
profile.c
ptrace.c
ptrace: use fsuid, fsgid, effective creds for fs access checks
2016-01-20 17:09:18 -08:00
range.c
reboot.c
relay.c
wrappers for ->i_mutex access
2016-01-22 18:04:28 -05:00
resource.c
restrict /dev/mem to idle io memory ranges
2016-01-09 06:30:49 -08:00
seccomp.c
seccomp, ptrace: add support for dumping seccomp filters
2015-10-27 19:55:13 -07:00
signal.c
kernel/signal.c: unexport sigsuspend()
2015-11-20 16:17:32 -08:00
smp.c
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
2015-11-06 17:50:42 -08:00
smpboot.c
stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
2015-10-20 10:23:55 +02:00
smpboot.h
softirq.c
stacktrace.c
stop_machine.c
kernel/stop_machine.c: remove CONFIG_SMP dependencies
2016-01-16 11:17:24 -08:00
sys.c
prctl: take mmap sem for writing to protect against others
2016-01-20 17:09:18 -08:00
sys_ni.c
vfs: add copy_file_range syscall and vfs helper
2015-12-01 14:00:53 -05:00
sysctl.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-01-22 10:24:03 -08:00
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
torture: Consolidate cond_resched_rcu_qs() into stutter_wait()
2015-10-06 11:25:01 -07:00
tracepoint.c
tracepoint: Give priority to probes of tracepoints
2015-10-25 21:33:54 -04:00
tsacct.c
uid16.c
up.c
user-return-notifier.c
user.c
user_namespace.c
kernel/*: switch to memdup_user_nul()
2016-01-04 10:27:55 -05:00
utsname.c
utsname_sysctl.c
watchdog.c
Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2016-01-11 18:53:13 -08:00
workqueue.c
Revert "workqueue: make sure delayed work run in local cpu"
2016-02-09 16:11:26 -05:00
workqueue_internal.h