Re: [RT PATCH 2/2] timers: wakeup all timer waiters without holding the base lock

From: Steven Rostedt
Date: Thu Jul 14 2016 - 12:10:04 EST


On Thu, 14 Jul 2016 18:05:04 +0200
Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote:

> There should be no need to hold the base lock during the wakeup. There
> should be no boosting involved, the wakeup list has its own lock so it
> should be safe to do this without the lock.
>
> Cc: stable-rt@xxxxxxxxxxxxxxx

Nothing against this patch, but as you marked it for stable, can you
add to the change log what issue you had that caused you to make this
change?

-- Steve

> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> ---
> 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 b3c3d3a6216f..716ef84a5d87 100644
> --- a/kernel/time/timer.c
> +++ b/kernel/time/timer.c
> @@ -1313,8 +1313,8 @@ static inline void __run_timers(struct tvec_base *base)
> }
> }
> }
> - wakeup_timer_waiters(base);
> spin_unlock_irq(&base->lock);
> + wakeup_timer_waiters(base);
> }
>
> #ifdef CONFIG_NO_HZ_COMMON