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author | Peter Zijlstra <peterz@infradead.org> | 2018-04-30 14:51:01 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2018-05-04 07:54:54 +0200 |
commit | b5bf9a90bbebffba888c9144c5a8a10317b04064 (patch) | |
tree | 4c059f0785c26ca66df0009544a23b68f7228be3 /include/linux/sched | |
parent | 85f1abe0019fcb3ea10df7029056cf42702283a8 (diff) | |
download | linux-stable-b5bf9a90bbebffba888c9144c5a8a10317b04064.tar.gz linux-stable-b5bf9a90bbebffba888c9144c5a8a10317b04064.tar.bz2 linux-stable-b5bf9a90bbebffba888c9144c5a8a10317b04064.zip |
sched/core: Introduce set_special_state()
Gaurav reported a perceived problem with TASK_PARKED, which turned out
to be a broken wait-loop pattern in __kthread_parkme(), but the
reported issue can (and does) in fact happen for states that do not do
condition based sleeps.
When the 'current->state = TASK_RUNNING' store of a previous
(concurrent) try_to_wake_up() collides with the setting of a 'special'
sleep state, we can loose the sleep state.
Normal condition based wait-loops are immune to this problem, but for
sleep states that are not condition based are subject to this problem.
There already is a fix for TASK_DEAD. Abstract that and also apply it
to TASK_STOPPED and TASK_TRACED, both of which are also without
condition based wait-loop.
Reported-by: Gaurav Kohli <gkohli@codeaurora.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/sched')
-rw-r--r-- | include/linux/sched/signal.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index a7ce74c74e49..113d1ad1ced7 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -280,7 +280,7 @@ static inline void kernel_signal_stop(void) { spin_lock_irq(¤t->sighand->siglock); if (current->jobctl & JOBCTL_STOP_DEQUEUED) - __set_current_state(TASK_STOPPED); + set_special_state(TASK_STOPPED); spin_unlock_irq(¤t->sighand->siglock); schedule(); |