lkml.org 
[lkml]   [2024]   [Feb]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] hrtimer: select housekeeping CPU during migration
From

On 2/11/24 08:52, Costa Shulyupin wrote:
> because during CPU deactivation a timer can migrate
> to isolated CPU and break CPU isolation.
>
> For reference see function get_nohz_timer_target,
> which selects CPU for new timers from housekeeping_cpumask(HK_TYPE_TIMER)
>
> Inspired by Waiman Long <longman@redhat.com>
>
> Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>

Nit: It is unusual to begin the commit log with "because".

Other than that, the patch looks good to me.

Reviewed-by:  Waiman Long <longman@redhat.com>

> ---
> kernel/time/hrtimer.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
> index f82997cf53b6..460d916e24b7 100644
> --- a/kernel/time/hrtimer.c
> +++ b/kernel/time/hrtimer.c
> @@ -2227,7 +2227,7 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
> int hrtimers_cpu_dying(unsigned int dying_cpu)
> {
> struct hrtimer_cpu_base *old_base, *new_base;
> - int i, ncpu = cpumask_first(cpu_active_mask);
> + int i, ncpu = cpumask_any_and(cpu_active_mask, housekeeping(HK_TYPE_TIMER));
> pr_debug("ncpu=%d, dying_cpu=%d\n", ncpu, dying_cpu);
>
> tick_cancel_sched_timer(dying_cpu);


\
 
 \ /
  Last update: 2024-05-27 14:57    [W:0.467 / U:0.304 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site