Oleg Nesterov 13c22168b7 destroy_workqueue() can livelock ...

Pointed out by Michal Schmidt <mschmidt@redhat.com>.

The bug was introduced in 2.6.22 by me.

cleanup_workqueue_thread() does flush_cpu_workqueue(cwq) in a loop until
->worklist becomes empty.  This is live-lockable, a re-niced caller can get
CPU after wake_up() and insert a new barrier before the lower-priority
cwq->thread has a chance to clear ->current_work.

Change cleanup_workqueue_thread() to do flush_cpu_workqueue(cwq) only once.
 We can rely on the fact that run_workqueue() won't return until it flushes
all works.  So it is safe to call kthread_stop() after that, the "should
stop" request won't be noticed until run_workqueue() returns.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2007-07-17 10:23:03 -07:00

..

irq

Improve behaviour of spurious IRQ detect

2007-07-16 09:05:46 -07:00

power

PM: introduce set_target method in pm_ops

2007-07-01 12:29:44 -07:00

time

kallsyms: make KSYM_NAME_LEN include space for trailing '\0'

2007-07-17 10:23:03 -07:00

.gitignore

gitignore: ignore more generated files

2006-01-03 11:35:26 +01:00

acct.c

[PATCH] kernel: change uses of f_{dentry, vfsmnt} to use f_path

2006-12-08 08:28:42 -08:00

audit.c

Freezer: make kernel threads nonfreezable by default

2007-07-17 10:23:02 -07:00

audit.h

Audit: add TTY input auditing

2007-07-16 09:05:47 -07:00

auditfilter.c

audit: fix oops removing watch if audit disabled

2007-06-24 08:59:12 -07:00

auditsc.c

kerneldoc fix in audit_core_dumps

2007-07-16 09:05:48 -07:00

capability.c

[PATCH] pid: replace do/while_each_task_pid with do/while_each_pid_task

2007-02-12 09:48:32 -08:00

compat.c

signal/timer/event: timerfd compat code

2007-05-11 08:29:36 -07:00

configs.c

use simple_read_from_buffer in kernel/

2007-05-09 12:30:49 -07:00

cpu.c

microcode: use suspend-related CPU hotplug notifications

2007-05-09 12:30:56 -07:00

cpuset.c

Reduce cpuset.c write_lock_irq() to read_lock()

2007-07-16 09:05:43 -07:00

delayacct.c

sched: update delay-accounting to use CFS's precise stats

2007-07-09 18:52:00 +02:00

die_notifier.c

move die notifier handling to common code

2007-05-08 11:15:04 -07:00

dma.c

[PATCH] struct seq_operations and struct file_operations constification

2006-12-07 08:39:46 -08:00

exec_domain.c

Remove obsolete #include <linux/config.h>

2006-06-30 19:25:36 +02:00

exit.c

Freezer: make kernel threads nonfreezable by default

2007-07-17 10:23:02 -07:00

extable.c

[PATCH] symbol_put_addr() locks kernel

2006-05-15 11:20:55 -07:00

fork.c

Freezer: make kernel threads nonfreezable by default

2007-07-17 10:23:02 -07:00

futex_compat.c

Revert "futex_requeue_pi optimization"

2007-06-18 09:48:41 -07:00

futex.c

FUTEX: Tidy up the code

2007-07-16 09:05:49 -07:00

hrtimer.c

[HRTIMER] Fix cpu pointer arg to clockevents_notify()

2007-07-16 17:29:56 -07:00

itimer.c

The scheduled -EINVAL for invalid timevals in setitimer

2007-05-08 11:15:13 -07:00

kallsyms.c

kallsyms: make KSYM_NAME_LEN include space for trailing '\0'

2007-07-17 10:23:03 -07:00

Kconfig.hz

[PATCH] HZ: 300Hz support

2006-12-07 08:39:36 -08:00

Kconfig.preempt

Fix trivial typos in Kconfig* files

2007-05-09 07:12:20 +02:00

kexec.c

kdump/kexec: calculate note size at compile time

2007-05-08 11:15:07 -07:00

kfifo.c

is_power_of_2: kernel/kfifo.c

2007-07-16 09:05:50 -07:00

kmod.c

wait_for_helper: remove unneeded do_sigaction()

2007-05-09 12:30:53 -07:00

kprobes.c

Kprobes: The ON/OFF knob thru debugfs

2007-05-08 11:15:19 -07:00

ksysfs.c

remove "struct subsystem" as it is no longer needed

2007-05-02 18:57:59 -07:00

kthread.c

mm: fix improper .init-type section references

2007-07-16 09:05:36 -07:00

latency.c

[PATCH] severing module.h->sched.h

2006-12-04 02:00:22 -05:00

lockdep_internals.h

[PATCH] lockdep: more chains

2006-12-07 08:39:43 -08:00

lockdep_proc.c

[PATCH] remove many unneeded #includes of sched.h

2007-02-14 08:09:54 -08:00

lockdep.c

kallsyms: make KSYM_NAME_LEN include space for trailing '\0'

2007-07-17 10:23:03 -07:00

Makefile

user namespace: add the framework

2007-07-16 09:05:47 -07:00

module.c

kallsyms: make KSYM_NAME_LEN include space for trailing '\0'

2007-07-17 10:23:03 -07:00

mutex-debug.c

[PATCH] remove many unneeded #includes of sched.h

2007-02-14 08:09:54 -08:00

mutex-debug.h

[PATCH] lockdep: better lock debugging

2006-07-03 15:27:01 -07:00

mutex.c

wrap access to thread_info

2007-05-09 12:30:56 -07:00

mutex.h

[PATCH] lockdep: prove mutex locking correctness

2006-07-03 15:27:04 -07:00

nsproxy.c

namespace: ensure clone_flags are always stored in an unsigned long

2007-07-16 09:05:48 -07:00

panic.c

Report that kernel is tainted if there was an OOPS

2007-07-17 10:23:02 -07:00

params.c

sysfs: kill unnecessary attribute->owner

2007-07-11 16:09:06 -07:00

pid.c

namespace: ensure clone_flags are always stored in an unsigned long

2007-07-16 09:05:48 -07:00

posix-cpu-timers.c

sched: make posix-cpu-timers use CFS's accounting information

2007-07-09 18:51:58 +02:00

posix-timers.c

posix-timers: Prevent softirq starvation by small intervals and SIG_IGN

2007-06-21 15:57:04 -07:00

printk.c

kernel/printk.c: document possible deadlock against scheduler

2007-07-16 09:05:52 -07:00

profile.c

Detach sched.h from mm.h

2007-05-21 09:18:19 -07:00

ptrace.c

PTRACE_POKEDATA consolidation

2007-07-17 10:23:03 -07:00

rcupdate.c

Add suspend-related notifications for CPU hotplug

2007-05-09 12:30:56 -07:00

rcutorture.c

Freezer: make kernel threads nonfreezable by default

2007-07-17 10:23:02 -07:00

relay.c

relay: fixup kerneldoc comment

2007-07-13 14:14:28 +02:00

resource.c

libata/IDE: remove combined mode quirk

2007-04-28 14:15:59 -04:00

rtmutex_common.h

FUTEX: Tidy up the code

2007-07-16 09:05:49 -07:00

rtmutex-debug.c

FUTEX: Tidy up the code

2007-07-16 09:05:49 -07:00

rtmutex-debug.h

[PATCH] lockdep: better lock debugging

2006-07-03 15:27:01 -07:00

rtmutex-tester.c

Freezer: make kernel threads nonfreezable by default

2007-07-17 10:23:02 -07:00

rtmutex.c

FUTEX: Tidy up the code

2007-07-16 09:05:49 -07:00

rtmutex.h

[PATCH] lockdep: better lock debugging

2006-07-03 15:27:01 -07:00

rwsem.c

Lockdep treats down_write_trylock like regular down_write

2007-05-08 11:15:09 -07:00

sched_debug.c

[PATCH] sched: remove stale version info from kernel/sched_debug.c

2007-07-13 10:10:41 -07:00

sched_fair.c

sched: cfs core, kernel/sched_fair.c

2007-07-09 18:51:58 +02:00

sched_idletask.c

sched: cfs core, kernel/sched_idletask.c

2007-07-09 18:51:58 +02:00

sched_rt.c

sched: cfs core, kernel/sched_rt.c

2007-07-09 18:51:58 +02:00

sched_stats.h

sched: update delay-accounting to use CFS's precise stats

2007-07-09 18:52:00 +02:00

sched.c

Freezer: make kernel threads nonfreezable by default

2007-07-17 10:23:02 -07:00

seccomp.c

make seccomp zerocost in schedule

2007-07-16 09:05:50 -07:00

signal.c

vdso: print fatal signals

2007-07-16 09:05:43 -07:00

softirq.c

Freezer: make kernel threads nonfreezable by default

2007-07-17 10:23:02 -07:00

softlockup.c

Freezer: make kernel threads nonfreezable by default

2007-07-17 10:23:02 -07:00

spinlock.c

[PATCH] lockdep: spin_lock_irqsave_nested()

2006-11-25 13:28:34 -08:00

srcu.c

[PATCH] SRCU: report out-of-memory errors

2006-10-04 07:55:30 -07:00

stacktrace.c

[PATCH] lockdep: stacktrace subsystem, core

2006-07-03 15:27:02 -07:00

stop_machine.c

Fix stop_machine_run problem with naughty real time process

2007-07-16 09:05:41 -07:00

sys_ni.c

diskquota: 32bit quota tools on 64bit architectures

2007-07-16 09:05:48 -07:00

sys.c

move seccomp from /proc to a prctl

2007-07-16 09:05:50 -07:00

sysctl.c

proper prototype for proc_nr_files()

2007-07-17 10:23:03 -07:00

taskstats.c

taskstats: add context-switch counters

2007-07-16 09:05:46 -07:00

time.c

sys_time() speedup

2007-07-16 09:05:48 -07:00

timer.c

Slab allocators: Replace explicit zeroing with __GFP_ZERO

2007-07-17 10:23:02 -07:00

tsacct.c

[PATCH] time: x86_64: split x86_64/kernel/time.c up

2007-02-16 08:14:00 -08:00

uid16.c

header cleaning: don't include smp_lock.h when not used

2007-05-08 11:15:07 -07:00

user_namespace.c

fix create_new_namespaces() return value

2007-07-16 09:05:47 -07:00

user.c

user namespace: add the framework

2007-07-16 09:05:47 -07:00

utsname_sysctl.c

remove CONFIG_UTS_NS and CONFIG_IPC_NS

2007-07-16 09:05:47 -07:00

utsname.c

namespace: ensure clone_flags are always stored in an unsigned long

2007-07-16 09:05:48 -07:00

wait.c

Fix occurrences of "the the "

2007-05-09 08:57:56 +02:00

workqueue.c

destroy_workqueue() can livelock

2007-07-17 10:23:03 -07:00