Commit 52c063d1 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

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: default avatarThomas Gleixner <tglx@linutronix.de>
[ Rebase ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1658173.RkEEILFiQZ@vostro.rjw.lan


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent ffa48c0d

include/linux/clockchips.h

+0 −1
Original line number Diff line number Diff line
@@ -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,

};

include/linux/tick.h

+2 −0
Original line number Diff line number Diff line
@@ -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

kernel/cpu.c

+2 −0
Original line number Diff line number Diff line
@@ -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;

kernel/time/clockevents.c

+0 −4
Original line number Diff line number Diff line
@@ -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);

kernel/time/hrtimer.c

+0 −4
Original line number Diff line number Diff line
@@ -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:

	{

CRA Git | Maintained and supported by SUSTech CRA and CCSE