Re: [tip:timers/urgent] timers: Unconditionally check deferrable base

From: Paul E. McKenney
Date: Sun Jan 14 2018 - 17:44:21 EST


On Sun, Jan 14, 2018 at 02:31:07PM -0800, tip-bot for Thomas Gleixner wrote:
> Commit-ID: ed4bbf7910b28ce3c691aef28d245585eaabda06
> Gitweb: https://git.kernel.org/tip/ed4bbf7910b28ce3c691aef28d245585eaabda06
> Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> AuthorDate: Sun, 14 Jan 2018 23:19:49 +0100
> Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> CommitDate: Sun, 14 Jan 2018 23:25:33 +0100
>
> timers: Unconditionally check deferrable base
>
> When the timer base is checked for expired timers then the deferrable base
> must be checked as well. This was missed when making the deferrable base
> independent of base::nohz_active.

Very cool, thank you! I have fired up some of the dreaded TREE01 tests.

Thanx, Paul

> Fixes: ced6d5c11d3e ("timers: Use deferrable base independent of base::nohz_active")
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Sebastian Siewior <bigeasy@xxxxxxxxxxxxx>
> Cc: Paul McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: rt@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 89a9e1b..0bcf00e 100644
> --- a/kernel/time/timer.c
> +++ b/kernel/time/timer.c
> @@ -1696,7 +1696,7 @@ void run_local_timers(void)
> hrtimer_run_queues();
> /* Raise the softirq only if required. */
> if (time_before(jiffies, base->clk)) {
> - if (!IS_ENABLED(CONFIG_NO_HZ_COMMON) || !base->nohz_active)
> + if (!IS_ENABLED(CONFIG_NO_HZ_COMMON))
> return;
> /* CPU is awake, so check the deferrable base. */
> base++;
>