From ef8969bb552c1c75e997a42d3e2c576b6ed4025a Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sun, 25 Feb 2024 23:55:01 +0100 Subject: [PATCH] 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: Frederic Weisbecker Signed-off-by: Thomas Gleixner Reviewed-by: Thomas Gleixner Link: https://lore.kernel.org/r/20240225225508.11587-10-frederic@kernel.org --- include/linux/tick.h | 6 ------ kernel/cpu.c | 2 -- kernel/time/tick-common.c | 3 +++ kernel/time/tick-internal.h | 2 ++ 4 files changed, 5 insertions(+), 8 deletions(-) diff --git a/include/linux/tick.h b/include/linux/tick.h index afff4c207bd8..c7840ae8ebaf 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -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 diff --git a/kernel/cpu.c b/kernel/cpu.c index 263508073da8..5a8ad4f5ccf3 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -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; diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index b4af8c743b73..522414089c0d 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -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; } diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index a3243c4ac45f..5f2105e637bd 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -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