On Thu, 14 Jul 2016 18:05:03 +0200 Sebastian Andrzej Siewior <bige...@linutronix.de> wrote:
> The base lock is dropped during the invocation if the timer. That means > it is possible that we have one waiter while timer1 is running and once > this one finished, we get another waiter while timer2 is running. Since > we wake up only one waiter it is possible that we miss the other one. > This will probably heal itself over time because most of the time we > complete timers without an active wake up. > To avoid the scenario where we don't wake up all waiters at once, > wake_up_all() is used. > > Cc: stable...@vger.kernel.org > Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de> > --- > kernel/time/timer.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/time/timer.c b/kernel/time/timer.c > index 5f9d3599ef0a..b3c3d3a6216f 100644 > --- a/kernel/time/timer.c > +++ b/kernel/time/timer.c > @@ -1051,7 +1051,7 @@ static void wait_for_running_timer(struct timer_list > *timer) > base->running_timer != timer); > } > > -# define wakeup_timer_waiters(b) wake_up(&(b)->wait_for_running_timer) > +# define wakeup_timer_waiters(b) > wake_up_all(&(b)->wait_for_running_timer) OK, I just received this patch (way after patch 2) I'm assuming that patch two was done such that you don't do a "wake_up_all" under a spinlock. -- Steve > #else > static inline void wait_for_running_timer(struct timer_list *timer) > {