Peter Zijlstra cb6538e740 sched/wait: Fix a kthread race with wait_woken() ...

There is a race between kthread_stop() and the new wait_woken() that
can result in a lack of progress.

CPU 0                                    | CPU 1
                                         |
rfcomm_run()                             | kthread_stop()
  ...                                    |
  if (!test_bit(KTHREAD_SHOULD_STOP))    |
                                         |   set_bit(KTHREAD_SHOULD_STOP)
                                         |   wake_up_process()
    wait_woken()                         |   wait_for_completion()
      set_current_state(INTERRUPTIBLE)   |
      if (!WQ_FLAG_WOKEN)                |
        schedule_timeout()               |
                                         |

After which both tasks will wait.. forever.

Fix this by having wait_woken() check for kthread_should_stop() but
only for kthreads (obviously).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2014-11-04 07:17:44 +01:00

..

auto_group.c

sched: Change autogroup_move_group() to use for_each_thread()

2014-08-20 09:47:18 +02:00

auto_group.h

Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled"

2012-12-11 10:23:45 +01:00

clock.c

time: Replace __get_cpu_var uses

2014-08-26 13:45:44 -04:00

completion.c

sched: Move completion code from core.c to completion.c

2013-11-06 07:49:19 +01:00

core.c

sched: Exclude cond_resched() from nested sleep test

2014-10-28 10:56:57 +01:00

cpuacct.c

cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes

2014-07-15 11:05:09 -04:00

cpuacct.h

sched/cpuacct: Initialize root cpuacct earlier

2013-04-10 13:54:20 +02:00

cpudeadline.c

sched/deadline: Fix inter- exclusive cpusets migrations

2014-09-24 14:46:57 +02:00

cpudeadline.h

sched/deadline: Replace NR_CPUS arrays

2014-05-22 10:21:28 +02:00

cpupri.c

Merge commit '3cf2f34' into sched/core, to fix build error

2014-06-12 13:46:37 +02:00

cpupri.h

sched/cpupri: Replace NR_CPUS arrays

2014-05-22 10:21:29 +02:00

cputime.c

sched, time: Fix build error with 64 bit cputime_t on 32 bit systems

2014-10-03 05:46:55 +02:00

deadline.c

sched/deadline: Don't balance during wakeup if wakee is pinned

2014-10-28 10:48:02 +01:00

debug.c

sched: print_rq(): Don't use tasklist_lock

2014-09-24 14:47:04 +02:00

fair.c

sched/numa: Check all nodes when placing a pseudo-interleaved group

2014-10-28 10:47:52 +01:00

features.h

sched: Rename capacity related flags

2014-06-05 11:52:32 +02:00

idle_task.c

sched: Transform resched_task() into resched_curr()

2014-07-16 13:38:19 +02:00

idle.c

sched: Let the scheduler see CPU idle states

2014-09-24 14:46:58 +02:00

Makefile

sched/idle: Move cpu/idle.c to sched/idle.c

2014-02-11 09:58:30 +01:00

proc.c

cpuidle: menu: Lookup CPU runqueues less

2014-08-06 21:17:45 +02:00

rt.c

Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

2014-10-15 07:48:18 +02:00

sched.h

sched/deadline: Fix bandwidth check/update when migrating tasks between exclusive cpusets

2014-10-28 10:47:58 +01:00

stats.c

kernel: audit/fix non-modular users of module_init in core code

2014-04-03 16:21:07 -07:00

stats.h

sched: Micro-optimize by dropping unnecessary task_rq() calls

2013-09-25 13:51:06 +02:00

stop_task.c

sched: Add wrapper for checking task_struct::on_rq

2014-08-20 14:52:59 +02:00

wait.c

sched/wait: Fix a kthread race with wait_woken()

2014-11-04 07:17:44 +01:00