Re: [PATCH 05/14] hrtimer: Fix invalid wakeup in do_nanosleep

[Thomas Gleixner]

On Thu, 29 Aug 2013, Libin wrote:

> If thread is preempted before calling set_current_state(TASK_INTERRUPTIBLE),
> and the other thread set the condition followed with wake_up_process. After
> that when this thread is re-scheduled, calling set_current_state to set itself
> as state TASK_INTERRUPTIBLE, if it is preempted again after that and before
> __set_current_state(TASK_RUNNING), it triggers the invalid wakeup problem.

do_nanosleep() is only called from sys_nanosleep() and
sys_clock_nanosleep() user space interfaces.

So the task is not going to be woken up by some magic other thread
except by a signal. The latter is handled by the scheduler which will
return with state running. So what kind of problem are you trying to
solve?

Thanks,

	tglx



 
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