github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

tick/nohz: Reevaluate the tick for kicks flushed outside hardirq

Browse Source 
The nohz full kick relies on interrupt exit to reevaluate the
tick. However, a remote kick can also be flushed from task context without
an interrupt exit guaranteed to follow. If a tick dependency is set or an
earlier timer is queued after the idle-exit reevaluation, the required tick
update can be delayed until another interrupt.

Reevaluate the tick directly from the callback outside hardirq context.
Keep the existing interrupt exit handling for hardirq callbacks. The
offline flush remains harmless because tick_sched_timer_dying() has already
cleared TS_FLAG_NOHZ.

Fixes: 4b44a21dd6 ("irq_work, smp: Allow irq_work on call_single_queue")
Fixes: a5183862e7 ("tick/nohz: Conditionally restart tick on idle exit")
Suggested-by: Frederic Weisbecker <frederic@kernel.org>
Co-developed-by: He Rongguang <herongguang@linux.alibaba.com>
Signed-off-by: He Rongguang <herongguang@linux.alibaba.com>
Signed-off-by: Peng Wang <peng_wang@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20261023145101.8217-1-peng_wang@linux.alibaba.com
This commit is contained in:
Peng Wang 2026-10-23 22:51:00 +08:00 committed by Thomas Gleixner
parent 45aeb7b303
commit e389ae4288
1 changed files with 13 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
kernel/time/tick-sched.c
View File

@ -400,9 +400,21 @@ static bool can_stop_full_tick(int cpu, struct tick_sched *ts)
return true;
}
static void tick_nohz_full_update_tick(struct tick_sched *ts);
static void nohz_full_kick_func(struct irq_work *work)
{
/* Empty, the tick restart happens on tick_nohz_irq_exit() */
struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
if (WARN_ON_ONCE(!tick_nohz_full_cpu(smp_processor_id())))
return;
/* Task-context flushes may not be followed by an IRQ exit. */
if (!in_hardirq()) {
if (WARN_ON_ONCE(tick_sched_flag_test(ts, TS_FLAG_INIDLE)))
return;
tick_nohz_full_update_tick(ts);
}
}
static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) =