linux/kernel
Eric Dumazet c821990610 task_work: remove fifo ordering guarantee
In commit f341861fb0 ("task_work: add a scheduling point in
task_work_run()") I fixed a latency problem adding a cond_resched()
call.

Later, commit ac3d0da8f3 added yet another loop to reverse a list,
bringing back the latency spike :

I've seen in some cases this loop taking 275 ms, if for example a
process with 2,000,000 files is killed.

We could add yet another cond_resched() in the reverse loop, or we
can simply remove the reversal, as I do not think anything
would depend on order of task_work_add() submitted works.

Fixes: ac3d0da8f3 ("task_work: Make task_work_add() lockless")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05 13:46:58 -07:00
..
bpf bpf: fix bpf_perf_event_read() loop upper bound 2015-08-12 16:42:50 -07:00
configs kconfig: add xenconfig defconfig helper 2015-06-16 11:04:29 +01:00
debug debug: prevent entering debug mode on panic/exception. 2015-02-19 12:39:03 -06:00
events Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-09-03 08:08:17 -07:00
gcov gcov: add support for GCC 5.1 2015-06-30 19:44:57 -07:00
irq Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 14:33:35 -07:00
livepatch livepatch: Improve error handling in klp_disable_func() 2015-07-14 22:48:06 +02:00
locking locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics 2015-08-12 11:59:06 +02:00
power Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-block 2015-09-02 13:10:25 -07:00
printk printk: improve the description of /dev/kmsg line format 2015-06-30 19:44:59 -07:00
rcu rcu,locking: Privatize smp_mb__after_unlock_lock() 2015-08-04 08:49:21 -07:00
sched Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-03 15:46:07 -07:00
time Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 14:04:50 -07:00
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-09-03 08:08:17 -07:00
.gitignore
acct.c acct: check FMODE_CAN_WRITE 2015-04-11 22:27:55 -04:00
async.c
audit_tree.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
audit_watch.c VFS: audit: d_backing_inode() annotations 2015-04-15 15:06:55 -04:00
audit.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-06-27 13:53:16 -07:00
audit.h Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-04-22 14:49:23 -07:00
auditfilter.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-02-11 20:07:47 -08:00
auditsc.c Fix broken audit tests for exec arg len 2015-07-08 09:33:38 -07:00
backtracetest.c
bounds.c
capability.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
cgroup_freezer.c cgroup: allow a cgroup subsystem to reject a fork 2015-07-14 17:29:23 -04:00
cgroup_pids.c cgroup: pids: fix invalid get/put usage 2015-08-25 14:19:25 -04:00
cgroup.c Merge branch 'for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2015-09-02 08:04:23 -07:00
compat.c compat: cleanup coding in compat_get_bitmap() and compat_put_bitmap() 2015-06-04 23:57:18 +02:00
configs.c
context_tracking.c context_tracking: Inherit TIF_NOHZ through forks instead of context switches 2015-05-07 12:02:51 +02:00
cpu_pm.c
cpu.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-08-31 20:26:22 -07:00
cpuset.c cpuset: use trialcs->mems_allowed as a temp variable 2015-08-10 11:18:41 -04:00
crash_dump.c
cred.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
delayacct.c
dma.c
elfcore.c
exec_domain.c Remove rest of exec domains. 2015-04-12 21:03:31 +02:00
exit.c kernel: exit: fix typo in comment 2015-08-07 13:59:49 +02:00
extable.c
fork.c Merge branch 'for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2015-09-02 08:04:23 -07:00
freezer.c
futex_compat.c
futex.c futex: Make should_fail_futex() static 2015-07-20 21:43:54 +02:00
groups.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
hung_task.c kernel/hung_task.c: change hung_task.c to use for_each_process_thread() 2015-04-15 16:35:22 -07:00
irq_work.c
jump_label.c locking/static_keys: Add selftest 2015-08-03 11:34:16 +02:00
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/qrwlock: Rename QUEUE_RWLOCK to QUEUED_RWLOCKS 2015-05-12 09:46:00 +02:00
Kconfig.preempt
kexec.c kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path 2015-06-30 19:44:57 -07:00
kmod.c
kprobes.c perf/x86/hw_breakpoints: Disallow kernel breakpoints unless kprobe-safe 2015-08-04 10:16:54 +02:00
ksysfs.c
kthread.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-08-31 20:26:22 -07:00
latencytop.c
Makefile cgroup: implement the PIDs subsystem 2015-07-14 17:29:23 -04:00
module_signing.c
module-internal.h
module.c module: weaken locking assertion for oops path. 2015-07-29 06:13:22 +09:30
notifier.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 08:40:25 -07:00
nsproxy.c
padata.c padata: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:38 -08:00
panic.c kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path 2015-06-30 19:44:57 -07:00
params.c Minor merge needed, due to function move. 2015-07-01 10:49:25 -07:00
pid_namespace.c
pid.c rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN() 2015-07-22 15:27:32 -07:00
profile.c profile: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:38 -08:00
ptrace.c ptrace: ptrace_detach() can no longer race with SIGKILL 2015-04-17 09:04:06 -04:00
range.c
reboot.c kernel/reboot.c: add orderly_reboot for graceful reboot 2015-04-15 16:35:23 -07:00
relay.c kernel/relay.c: use kvfree() in relay_free_page_array() 2015-06-30 19:44:59 -07:00
resource.c mm: Fix bugs in region_is_ram() 2015-07-22 17:20:34 +02:00
seccomp.c seccomp, filter: add and use bpf_prog_create_from_user from seccomp 2015-05-09 17:35:05 -04:00
signal.c signal: fix information leak in copy_siginfo_to_user 2015-08-07 04:39:40 +03:00
smp.c smp: Fix error case handling in smp_call_function_*() 2015-04-19 13:19:23 -07:00
smpboot.c watchdog: add watchdog_cpumask sysctl to assist nohz 2015-06-24 17:49:40 -07:00
smpboot.h
softirq.c
stacktrace.c
stop_machine.c stop_machine: Remove cpu_stop_work's from list in cpu_stop_park() 2015-08-03 12:21:28 +02:00
sys_ni.c x86/ldt: Make modify_ldt() optional 2015-07-31 13:30:45 +02:00
sys.c vfs: Commit to never having exectuables on proc and sysfs. 2015-07-10 10:39:25 -05:00
sysctl_binary.c
sysctl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2015-07-03 15:20:57 -07:00
system_certificates.S
system_keyring.c
task_work.c task_work: remove fifo ordering guarantee 2015-09-05 13:46:58 -07:00
taskstats.c
test_kprobes.c
torture.c rcu: Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() 2015-05-27 12:56:15 -07:00
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c userns,pidns: Force thread group sharing, not signal handler sharing. 2015-08-12 14:55:28 -05:00
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog.c watchdog: add watchdog_cpumask sysctl to assist nohz 2015-06-24 17:49:40 -07:00
workqueue_internal.h
workqueue.c Merge branch 'for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2015-09-02 08:02:20 -07:00