d1748302f7
The automatic increase of the min_delta_ns of a clockevents device should be done in the clockevents code as the minimum delay is an attribute of the clockevents device. In addition not all architectures want the automatic adjustment, on a massively virtualized system it can happen that the programming of a clock event fails several times in a row because the virtual cpu has been rescheduled quickly enough. In that case the minimum delay will erroneously be increased with no way back. The new config symbol GENERIC_CLOCKEVENTS_MIN_ADJUST is used to enable the automatic adjustment. The config option is selected only for x86. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: john stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20110823133142.494157493@de.ibm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
144 lines
4.6 KiB
C
144 lines
4.6 KiB
C
/*
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* tick internal variable and functions used by low/high res code
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*/
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#include <linux/hrtimer.h>
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#include <linux/tick.h>
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#ifdef CONFIG_GENERIC_CLOCKEVENTS_BUILD
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#define TICK_DO_TIMER_NONE -1
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#define TICK_DO_TIMER_BOOT -2
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DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
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extern ktime_t tick_next_period;
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extern ktime_t tick_period;
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extern int tick_do_timer_cpu __read_mostly;
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extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
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extern void tick_handle_periodic(struct clock_event_device *dev);
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extern void clockevents_shutdown(struct clock_event_device *dev);
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/*
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* NO_HZ / high resolution timer shared code
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*/
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#ifdef CONFIG_TICK_ONESHOT
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extern void tick_setup_oneshot(struct clock_event_device *newdev,
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void (*handler)(struct clock_event_device *),
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ktime_t nextevt);
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extern int tick_program_event(ktime_t expires, int force);
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extern void tick_oneshot_notify(void);
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extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
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extern void tick_resume_oneshot(void);
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# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
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extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
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extern void tick_broadcast_oneshot_control(unsigned long reason);
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extern void tick_broadcast_switch_to_oneshot(void);
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extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
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extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
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extern int tick_broadcast_oneshot_active(void);
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extern void tick_check_oneshot_broadcast(int cpu);
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bool tick_broadcast_oneshot_available(void);
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# else /* BROADCAST */
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static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
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{
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BUG();
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}
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static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
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static inline void tick_broadcast_switch_to_oneshot(void) { }
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static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
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static inline int tick_broadcast_oneshot_active(void) { return 0; }
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static inline void tick_check_oneshot_broadcast(int cpu) { }
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static inline bool tick_broadcast_oneshot_available(void) { return true; }
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# endif /* !BROADCAST */
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#else /* !ONESHOT */
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static inline
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void tick_setup_oneshot(struct clock_event_device *newdev,
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void (*handler)(struct clock_event_device *),
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ktime_t nextevt)
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{
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BUG();
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}
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static inline void tick_resume_oneshot(void)
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{
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BUG();
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}
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static inline int tick_program_event(ktime_t expires, int force)
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{
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return 0;
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}
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static inline void tick_oneshot_notify(void) { }
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static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
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{
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BUG();
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}
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static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
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static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
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static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
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{
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return 0;
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}
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static inline int tick_broadcast_oneshot_active(void) { return 0; }
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static inline bool tick_broadcast_oneshot_available(void) { return false; }
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#endif /* !TICK_ONESHOT */
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/*
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* Broadcasting support
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*/
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#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
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extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
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extern int tick_check_broadcast_device(struct clock_event_device *dev);
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extern int tick_is_broadcast_device(struct clock_event_device *dev);
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extern void tick_broadcast_on_off(unsigned long reason, int *oncpu);
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extern void tick_shutdown_broadcast(unsigned int *cpup);
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extern void tick_suspend_broadcast(void);
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extern int tick_resume_broadcast(void);
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extern void
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tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
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#else /* !BROADCAST */
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static inline int tick_check_broadcast_device(struct clock_event_device *dev)
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{
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return 0;
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}
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static inline int tick_is_broadcast_device(struct clock_event_device *dev)
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{
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return 0;
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}
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static inline int tick_device_uses_broadcast(struct clock_event_device *dev,
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int cpu)
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{
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return 0;
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}
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static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
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static inline void tick_broadcast_on_off(unsigned long reason, int *oncpu) { }
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static inline void tick_shutdown_broadcast(unsigned int *cpup) { }
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static inline void tick_suspend_broadcast(void) { }
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static inline int tick_resume_broadcast(void) { return 0; }
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/*
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* Set the periodic handler in non broadcast mode
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*/
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static inline void tick_set_periodic_handler(struct clock_event_device *dev,
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int broadcast)
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{
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dev->event_handler = tick_handle_periodic;
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}
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#endif /* !BROADCAST */
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/*
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* Check, if the device is functional or a dummy for broadcast
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*/
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static inline int tick_device_is_functional(struct clock_event_device *dev)
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{
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return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
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}
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#endif
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extern void do_timer(unsigned long ticks);
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extern seqlock_t xtime_lock;
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