Commit-ID: 52c063d1adbc16c76e70fffa20727fcd4e9343b3 Gitweb: http://git.kernel.org/tip/52c063d1adbc16c76e70fffa20727fcd4e9343b3 Author: Thomas Gleixner <t...@linutronix.de> AuthorDate: Fri, 3 Apr 2015 02:37:24 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 3 Apr 2015 08:44:36 +0200
clockevents: Make tick handover explicit clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the tick_handover call and invoke it explicitely from the hotplug code. Temporary solution will be cleaned up in later patches. Signed-off-by: Thomas Gleixner <t...@linutronix.de> [ Rebase ] Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: John Stultz <john.stu...@linaro.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Andrew Morton <a...@linux-foundation.org> Link: http://lkml.kernel.org/r/1658173.rkeeilf...@vostro.rjw.lan Signed-off-by: Ingo Molnar <mi...@kernel.org> --- include/linux/clockchips.h | 1 - include/linux/tick.h | 2 ++ kernel/cpu.c | 2 ++ kernel/time/clockevents.c | 4 ---- kernel/time/hrtimer.c | 4 ---- kernel/time/tick-common.c | 9 ++++++--- kernel/time/tick-internal.h | 1 - 7 files changed, 10 insertions(+), 13 deletions(-) diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index f97f498..f4bde22 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -11,7 +11,6 @@ /* Clock event notification values */ enum clock_event_nofitiers { CLOCK_EVT_NOTIFY_ADD, - CLOCK_EVT_NOTIFY_CPU_DYING, CLOCK_EVT_NOTIFY_CPU_DEAD, }; diff --git a/include/linux/tick.h b/include/linux/tick.h index 6119321..2c68fa3 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -19,12 +19,14 @@ extern void tick_unfreeze(void); extern void tick_suspend_local(void); /* Should be core only, but XEN resume magic and ARM BL switcher require it */ extern void tick_resume_local(void); +extern void tick_handover_do_timer(void); #else /* CONFIG_GENERIC_CLOCKEVENTS */ static inline void tick_init(void) { } static inline void tick_freeze(void) { } static inline void tick_unfreeze(void) { } static inline void tick_suspend_local(void) { } static inline void tick_resume_local(void) { } +static inline void tick_handover_do_timer(void) { } #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ #ifdef CONFIG_TICK_ONESHOT diff --git a/kernel/cpu.c b/kernel/cpu.c index af5db20..eba7eaa 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -339,6 +339,8 @@ static int __ref take_cpu_down(void *_param) return err; cpu_notify(CPU_DYING | param->mod, param->hcpu); + /* Give up timekeeping duties */ + tick_handover_do_timer(); /* Park the stopper thread */ kthread_park(current); return 0; diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index be9abf3..88fb3b9 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -655,10 +655,6 @@ int clockevents_notify(unsigned long reason, void *arg) raw_spin_lock_irqsave(&clockevents_lock, flags); switch (reason) { - case CLOCK_EVT_NOTIFY_CPU_DYING: - tick_handover_do_timer(arg); - break; - case CLOCK_EVT_NOTIFY_CPU_DEAD: tick_shutdown_broadcast_oneshot(arg); tick_shutdown_broadcast(arg); diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 721d29b..6a7a64e 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1707,10 +1707,6 @@ static int hrtimer_cpu_notify(struct notifier_block *self, break; #ifdef CONFIG_HOTPLUG_CPU - case CPU_DYING: - case CPU_DYING_FROZEN: - clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DYING, &scpu); - break; case CPU_DEAD: case CPU_DEAD_FROZEN: { diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index e28ba5c..055c868 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -332,20 +332,23 @@ out_bc: tick_install_broadcast_device(newdev); } +#ifdef CONFIG_HOTPLUG_CPU /* * Transfer the do_timer job away from a dying cpu. * - * Called with interrupts disabled. + * Called with interrupts disabled. Not locking required. If + * tick_do_timer_cpu is owned by this cpu, nothing can change it. */ -void tick_handover_do_timer(int *cpup) +void tick_handover_do_timer(void) { - if (*cpup == tick_do_timer_cpu) { + if (tick_do_timer_cpu == smp_processor_id()) { int cpu = cpumask_first(cpu_online_mask); tick_do_timer_cpu = (cpu < nr_cpu_ids) ? cpu : TICK_DO_TIMER_NONE; } } +#endif /* * Shutdown an event device on a given cpu: diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index 0266f9d..aabcb5d 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -20,7 +20,6 @@ extern int tick_do_timer_cpu __read_mostly; extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast); extern void tick_handle_periodic(struct clock_event_device *dev); extern void tick_check_new_device(struct clock_event_device *dev); -extern void tick_handover_do_timer(int *cpup); extern void tick_shutdown(unsigned int *cpup); extern void tick_suspend(void); extern void tick_resume(void); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
