linux/kernel/time/tick-internal.h
Thomas Gleixner cd05a1f818 [PATCH] clockevents: Fix suspend/resume to disk hangs
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>
2007-03-16 19:35:25 -07:00

124 lines
3.9 KiB
C

/*
* tick internal variable and functions used by low/high res code
*/
DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
extern spinlock_t tick_device_lock;
extern ktime_t tick_next_period;
extern ktime_t tick_period;
extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
extern void tick_handle_periodic(struct clock_event_device *dev);
/*
* NO_HZ / high resolution timer shared code
*/
#ifdef CONFIG_TICK_ONESHOT
extern void tick_setup_oneshot(struct clock_event_device *newdev,
void (*handler)(struct clock_event_device *),
ktime_t nextevt);
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)
{
BUG();
}
static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
static inline void tick_broadcast_switch_to_oneshot(void) { }
static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
# endif /* !BROADCAST */
#else /* !ONESHOT */
static inline
void tick_setup_oneshot(struct clock_event_device *newdev,
void (*handler)(struct clock_event_device *),
ktime_t nextevt)
{
BUG();
}
static inline void tick_resume_oneshot(void)
{
BUG();
}
static inline int tick_program_event(ktime_t expires, int force)
{
return 0;
}
static inline void tick_oneshot_notify(void) { }
static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
{
BUG();
}
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 */
/*
* Broadcasting support
*/
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
extern int tick_do_broadcast(cpumask_t mask);
extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
extern int tick_check_broadcast_device(struct clock_event_device *dev);
extern int tick_is_broadcast_device(struct clock_event_device *dev);
extern void tick_broadcast_on_off(unsigned long reason, int *oncpu);
extern void tick_shutdown_broadcast(unsigned int *cpup);
extern void tick_suspend_broadcast(void);
extern int tick_resume_broadcast(void);
extern void
tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
#else /* !BROADCAST */
static inline int tick_check_broadcast_device(struct clock_event_device *dev)
{
return 0;
}
static inline int tick_is_broadcast_device(struct clock_event_device *dev)
{
return 0;
}
static inline int tick_device_uses_broadcast(struct clock_event_device *dev,
int cpu)
{
return 0;
}
static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
static inline void tick_broadcast_on_off(unsigned long reason, int *oncpu) { }
static inline void tick_shutdown_broadcast(unsigned int *cpup) { }
static inline void tick_suspend_broadcast(void) { }
static inline int tick_resume_broadcast(void) { return 0; }
/*
* Set the periodic handler in non broadcast mode
*/
static inline void tick_set_periodic_handler(struct clock_event_device *dev,
int broadcast)
{
dev->event_handler = tick_handle_periodic;
}
#endif /* !BROADCAST */
/*
* Check, if the device is functional or a dummy for broadcast
*/
static inline int tick_device_is_functional(struct clock_event_device *dev)
{
return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
}