Commit ef8969bb authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Thomas Gleixner
Browse files

tick: Move broadcast cancellation up to CPUHP_AP_TICK_DYING 



The broadcast shutdown code is executed through a random explicit call
within stop machine from the outgoing CPU.

However the tick broadcast is a midware between the tick callback and
the clocksource, therefore it makes more sense to shut it down after the
tick callback and before the clocksource drivers.

Move it instead to the common tick shutdown CPU hotplug state where
related operations can be ordered from highest to lowest level.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240225225508.11587-10-frederic@kernel.org
parent f04e5122

include/linux/tick.h

+0 −6
Original line number Diff line number Diff line
@@ -73,12 +73,6 @@ extern void tick_broadcast_control(enum tick_broadcast_mode mode); 
static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }

#endif /* BROADCAST */



#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)

extern void tick_offline_cpu(unsigned int cpu);

#else

static inline void tick_offline_cpu(unsigned int cpu) { }

#endif



#ifdef CONFIG_GENERIC_CLOCKEVENTS

extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);

#else

kernel/cpu.c

+0 −2
Original line number Diff line number Diff line
@@ -1324,8 +1324,6 @@ static int take_cpu_down(void *_param) 
	 */

	cpuhp_invoke_callback_range_nofail(false, cpu, st, target);



	/* Remove CPU from timer broadcasting */

	tick_offline_cpu(cpu);

	/* Park the stopper thread */

	stop_machine_park(cpu);

	return 0;

kernel/time/tick-common.c

+3 −0
Original line number Diff line number Diff line
@@ -412,6 +412,9 @@ int tick_cpu_dying(unsigned int dying_cpu) 


	tick_cancel_sched_timer(dying_cpu);



	/* Remove CPU from timer broadcasting */

	tick_offline_cpu(dying_cpu);



	return 0;

}

kernel/time/tick-internal.h

+2 −0
Original line number Diff line number Diff line
@@ -142,8 +142,10 @@ static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_ 
#endif /* !(BROADCAST && ONESHOT) */



#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)

extern void tick_offline_cpu(unsigned int cpu);

extern void tick_broadcast_offline(unsigned int cpu);

#else

static inline void tick_offline_cpu(unsigned int cpu) { }

static inline void tick_broadcast_offline(unsigned int cpu) { }

#endif