[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: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Soeren Sonnenburg <kernel@nn7.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 5bdbc74..17c29dc 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -206,6 +206,7 @@
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 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.
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 067ba2c..b74860a 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -459,6 +459,18 @@
}
/*
+ * 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
*/
static inline int hrtimer_cb_pending(const struct hrtimer *timer)
diff --git a/kernel/timer.c b/kernel/timer.c
index 440048a..dd6c2c1 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1016,7 +1016,7 @@
clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
/* Resume hrtimers */
- clock_was_set();
+ hres_timers_resume();
return 0;
}