Commit 9a574ea9 authored by Tim Chen's avatar Tim Chen Committed by Thomas Gleixner
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tick/sched: Preserve number of idle sleeps across CPU hotplug events 



Commit 71fee48f ("tick-sched: Fix idle and iowait sleeptime accounting vs
CPU hotplug") preserved total idle sleep time and iowait sleeptime across
CPU hotplug events.

Similar reasoning applies to the number of idle calls and idle sleeps to
get the proper average of sleep time per idle invocation.

Preserve those fields too.

Fixes: 71fee48f ("tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug")
Signed-off-by: default avatarTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240122233534.3094238-1-tim.c.chen@linux.intel.com
parent 64464955

kernel/time/tick-sched.c

+5 −0
Original line number Diff line number Diff line
@@ -1577,6 +1577,7 @@ void tick_cancel_sched_timer(int cpu) 
{

	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);

	ktime_t idle_sleeptime, iowait_sleeptime;

	unsigned long idle_calls, idle_sleeps;



# ifdef CONFIG_HIGH_RES_TIMERS

	if (ts->sched_timer.base)
@@ -1585,9 +1586,13 @@ void tick_cancel_sched_timer(int cpu) 


	idle_sleeptime = ts->idle_sleeptime;

	iowait_sleeptime = ts->iowait_sleeptime;

	idle_calls = ts->idle_calls;

	idle_sleeps = ts->idle_sleeps;

	memset(ts, 0, sizeof(*ts));

	ts->idle_sleeptime = idle_sleeptime;

	ts->iowait_sleeptime = iowait_sleeptime;

	ts->idle_calls = idle_calls;

	ts->idle_sleeps = idle_sleeps;

}

#endif