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Commit 995f054f authored by Ingo Molnar's avatar Ingo Molnar Committed by Linus Torvalds
Browse files

[PATCH] high-res timers: resume fix 



Soeren Sonnenburg reported that upon resume he is getting
this backtrace:

 [<c0119637>] smp_apic_timer_interrupt+0x57/0x90
 [<c0142d30>] retrigger_next_event+0x0/0xb0
 [<c0104d30>] apic_timer_interrupt+0x28/0x30
 [<c0142d30>] retrigger_next_event+0x0/0xb0
 [<c0140068>] __kfifo_put+0x8/0x90
 [<c0130fe5>] on_each_cpu+0x35/0x60
 [<c0143538>] clock_was_set+0x18/0x20
 [<c0135cdc>] timekeeping_resume+0x7c/0xa0
 [<c02aabe1>] __sysdev_resume+0x11/0x80
 [<c02ab0c7>] sysdev_resume+0x47/0x80
 [<c02b0b05>] device_power_up+0x5/0x10

it turns out that on resume we mistakenly re-enable interrupts too
early.  Do the timer retrigger only on the current CPU.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarSoeren Sonnenburg <kernel@nn7.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent bbef6181

include/linux/hrtimer.h

+3 −0
Original line number Diff line number Diff line
@@ -206,6 +206,7 @@ struct hrtimer_cpu_base { 
struct clock_event_device;



extern void clock_was_set(void);

extern void hres_timers_resume(void);

extern void hrtimer_interrupt(struct clock_event_device *dev);



/*
@@ -236,6 +237,8 @@ static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) 
 */

static inline void clock_was_set(void) { }



static inline void hres_timers_resume(void) { }



/*

 * In non high resolution mode the time reference is taken from

 * the base softirq time variable.

kernel/hrtimer.c

+12 −0
Original line number Diff line number Diff line
@@ -458,6 +458,18 @@ void clock_was_set(void) 
	on_each_cpu(retrigger_next_event, NULL, 0, 1);

}



/*

 * During resume we might have to reprogram the high resolution timer

 * interrupt (on the local CPU):

 */

void hres_timers_resume(void)

{

	WARN_ON_ONCE(num_online_cpus() > 1);



	/* Retrigger the CPU local events: */

	retrigger_next_event(NULL);

}



/*

 * Check, whether the timer is on the callback pending list

 */

kernel/timer.c

+1 −1
Original line number Diff line number Diff line
@@ -1016,7 +1016,7 @@ static int timekeeping_resume(struct sys_device *dev) 
	clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);



	/* Resume hrtimers */

	clock_was_set();

	hres_timers_resume();



	return 0;

}