The following commit has been merged into the timers/core branch of tip: Commit-ID: 86342554e102b0d18d50abec43d40f4fc92f1993 Gitweb: https://git.kernel.org/tip/86342554e102b0d18d50abec43d40f4fc92f1993 Author: Costa Shulyupin <costa.shul@xxxxxxxxxx> AuthorDate: Tue, 13 Feb 2024 18:46:51 +02:00 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Tue, 13 Feb 2024 20:44:14 +01:00 hrtimer: Select housekeeping CPU during migration During CPU-down hotplug, hrtimers may migrate to isolated CPUs, compromising CPU isolation. Address this issue by masking valid CPUs for hrtimers using housekeeping_cpumask(HK_TYPE_TIMER). Suggested-by: Waiman Long <longman@xxxxxxxxxx> Signed-off-by: Costa Shulyupin <costa.shul@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: Waiman Long <longman@xxxxxxxxxx> Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240213164650.2935909-3-costa.shul@xxxxxxxxxx --- 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 7607939..438208a 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -2221,8 +2221,8 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, int hrtimers_cpu_dying(unsigned int dying_cpu) { + int i, ncpu = cpumask_any_and(cpu_active_mask, housekeeping(HK_TYPE_TIMER)); struct hrtimer_cpu_base *old_base, *new_base; - int i, ncpu = cpumask_first(cpu_active_mask); tick_cancel_sched_timer(dying_cpu);