Re: [RFC PATCH 10/10] timer: Lower base clock forwarding threshold

From: Thomas Gleixner
Date: Thu Jul 02 2020 - 09:21:40 EST


Frederic Weisbecker <frederic@xxxxxxxxxx> writes:
> There is no apparent reason for not forwarding base->clk when it's 2
> jiffies late, except perhaps for past optimizations. But since forwarding
> has to be done at some point now anyway, this doesn't stand anymore.
>
> Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
> Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
> ---
> 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 439fee098e76..25a55c043297 100644
> --- a/kernel/time/timer.c
> +++ b/kernel/time/timer.c
> @@ -883,7 +883,7 @@ static inline void forward_timer_base(struct timer_base *base)
> * Also while executing timers, base->clk is 1 offset ahead
> * of jiffies to avoid endless requeuing to current jffies.
> */
> - if ((long)(jnow - base->clk) < 2)
> + if ((long)(jnow - base->clk) < 1)
> return;

The apparent reason is in the comment right above the condition ...

Thanks,

tglx