tick: Don't invoke tick_nohz_stop_sched_tick() if the cpu is offline

KAGA-KOKO · KAGA-KOKO · commit f7ea0fd639c2 · 2013-05-14T17:40:31.000+02:00
commit 5b39939 (nohz: Move ts->idle_calls incrementation into strict idle logic) moved code out of tick_nohz_stop_sched_tick() and missed to bail out when the cpu is offline. That's causing subsequent failures as an offline CPU is supposed to die and not to fiddle with nohz magic. Return false in can_stop_idle_tick() if the cpu is offline. Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz> Reported-and-tested-by: Prarit Bhargava <prarit@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Tony Luck <tony.luck@intel.com> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305132138160.2863@ionos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
@@ -469,6 +469,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
 	if (unlikely(!cpu_online(cpu))) {
 		if (cpu == tick_do_timer_cpu)
 			tick_do_timer_cpu = TICK_DO_TIMER_NONE;
+		return false;
 	}
 
 	if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))

Original file line number	Diff line number	Diff line change
`@@ -469,6 +469,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)`
`469`	`469`	`if (unlikely(!cpu_online(cpu))) {`
`470`	`470`	`if (cpu == tick_do_timer_cpu)`
`471`	`471`	`tick_do_timer_cpu = TICK_DO_TIMER_NONE;`
	`472`	`+ return false;`
`472`	`473`	`}`
`473`	`474`
`474`	`475`	`if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))`