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[PATCH] clockevents: Fix suspend/resume to disk hangs

Browse source 
I finally found a dual core box, which survives suspend/resume without
crashing in the middle of nowhere. Sigh, I never figured out from the
code and the bug reports what's going on.

The observed hangs are caused by a stale state transition of the clock
event devices, which keeps the RCU synchronization away from completion,
when the non boot CPU is brought back up.

The suspend/resume in oneshot mode needs the similar care as the
periodic mode during suspend to RAM. My assumption that the state
transitions during the different shutdown/bringups of s2disk would go
through the periodic boot phase and then switch over to highres resp.
nohz mode were simply wrong.

Add the appropriate suspend / resume handling for the non periodic
modes.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thomas Gleixner 2007-03-17 00:25:52 +01:00 committed by Linus Torvalds
parent 24c4ac070a
commit cd05a1f818
4 changed files with 51 additions and 12 deletions
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27
kernel/time/tick-broadcast.c
View file

@ -307,12 +307,19 @@ int tick_resume_broadcast(void)
spin_lock_irqsave(&tick_broadcast_lock, flags);
bc = tick_broadcast_device.evtdev;
if (bc) {
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC &&
!cpus_empty(tick_broadcast_mask))
tick_broadcast_start_periodic(bc);
broadcast = cpu_isset(smp_processor_id(), tick_broadcast_mask);
if (bc) {
switch (tick_broadcast_device.mode) {
case TICKDEV_MODE_PERIODIC:
if(!cpus_empty(tick_broadcast_mask))
tick_broadcast_start_periodic(bc);
broadcast = cpu_isset(smp_processor_id(),
tick_broadcast_mask);
break;
case TICKDEV_MODE_ONESHOT:
broadcast = tick_resume_broadcast_oneshot(bc);
break;
}
}
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
@ -347,6 +354,16 @@ static int tick_broadcast_set_event(ktime_t expires, int force)
}
}
int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
{
clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
if(!cpus_empty(tick_broadcast_oneshot_mask))
tick_broadcast_set_event(ktime_get(), 1);
return cpu_isset(smp_processor_id(), tick_broadcast_oneshot_mask);
}
/*
* Reprogram the broadcast device:
*

13
kernel/time/tick-common.c
View file

@ -298,18 +298,17 @@ static void tick_shutdown(unsigned int *cpup)
spin_unlock_irqrestore(&tick_device_lock, flags);
}
static void tick_suspend_periodic(void)
static void tick_suspend(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
unsigned long flags;
spin_lock_irqsave(&tick_device_lock, flags);
if (td->mode == TICKDEV_MODE_PERIODIC)
clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN);
clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN);
spin_unlock_irqrestore(&tick_device_lock, flags);
}
static void tick_resume_periodic(void)
static void tick_resume(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
unsigned long flags;
@ -317,6 +316,8 @@ static void tick_resume_periodic(void)
spin_lock_irqsave(&tick_device_lock, flags);
if (td->mode == TICKDEV_MODE_PERIODIC)
tick_setup_periodic(td->evtdev, 0);
else
tick_resume_oneshot();
spin_unlock_irqrestore(&tick_device_lock, flags);
}
@ -348,13 +349,13 @@ static int tick_notify(struct notifier_block *nb, unsigned long reason,
break;
case CLOCK_EVT_NOTIFY_SUSPEND:
tick_suspend_periodic();
tick_suspend();
tick_suspend_broadcast();
break;
case CLOCK_EVT_NOTIFY_RESUME:
if (!tick_resume_broadcast())
tick_resume_periodic();
tick_resume();
break;
default:

11
kernel/time/tick-internal.h
View file

@ -19,12 +19,13 @@ extern void tick_setup_oneshot(struct clock_event_device *newdev,
extern int tick_program_event(ktime_t expires, int force);
extern void tick_oneshot_notify(void);
extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
extern void tick_resume_oneshot(void);
# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
extern void tick_broadcast_oneshot_control(unsigned long reason);
extern void tick_broadcast_switch_to_oneshot(void);
extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
# else /* BROADCAST */
static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
{
@ -43,6 +44,10 @@ void tick_setup_oneshot(struct clock_event_device *newdev,
{
BUG();
}
static inline void tick_resume_oneshot(void)
{
BUG();
}
static inline int tick_program_event(ktime_t expires, int force)
{
return 0;
@ -54,6 +59,10 @@ static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
}
static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
{
return 0;
}
#endif /* !TICK_ONESHOT */
/*

12
kernel/time/tick-oneshot.c
View file

@ -40,6 +40,18 @@ int tick_program_event(ktime_t expires, int force)
}
}
/**
* tick_resume_onshot - resume oneshot mode
*/
void tick_resume_oneshot(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
struct clock_event_device *dev = td->evtdev;
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
tick_program_event(ktime_get(), 1);
}
/**
* tick_setup_oneshot - setup the event device for oneshot mode (hres or nohz)
*/