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: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240122233534.3094238-1-tim.c.chen@linux.intel.com

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index d2501673028da5e627aa08b51a103c181295cad3..01fb50c1b17e4f1b33285ae2ce2690f0747f8ee8 100644 (file)
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -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