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![Thomas Gleixner](/assets/img/avatar_default.png)
On every tick/hrtimer interrupt we update the offset variables of the clock bases. That's silly because these offsets change very seldom. Add a sequence counter to the time keeping code which keeps track of the offset updates (clock_was_set()). Have a sequence cache in the hrtimer cpu bases to evaluate whether the offsets must be updated or not. This allows us later to avoid pointless cacheline pollution. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20150414203501.132820245@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org>
26 lines
740 B
C
26 lines
740 B
C
#ifndef _KERNEL_TIME_TIMEKEEPING_H
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#define _KERNEL_TIME_TIMEKEEPING_H
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/*
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* Internal interfaces for kernel/time/
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*/
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extern ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq,
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ktime_t *offs_real,
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ktime_t *offs_boot,
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ktime_t *offs_tai);
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extern int timekeeping_valid_for_hres(void);
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extern u64 timekeeping_max_deferment(void);
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extern int timekeeping_inject_offset(struct timespec *ts);
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extern s32 timekeeping_get_tai_offset(void);
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extern void timekeeping_set_tai_offset(s32 tai_offset);
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extern int timekeeping_suspend(void);
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extern void timekeeping_resume(void);
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extern void do_timer(unsigned long ticks);
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extern void update_wall_time(void);
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extern seqlock_t jiffies_lock;
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#define CS_NAME_LEN 32
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#endif
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