linux/kernel/time/tick-sched.h
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   1#ifndef _TICK_SCHED_H
   2#define _TICK_SCHED_H
   3
   4#include <linux/hrtimer.h>
   5
   6enum tick_device_mode {
   7        TICKDEV_MODE_PERIODIC,
   8        TICKDEV_MODE_ONESHOT,
   9};
  10
  11struct tick_device {
  12        struct clock_event_device *evtdev;
  13        enum tick_device_mode mode;
  14};
  15
  16enum tick_nohz_mode {
  17        NOHZ_MODE_INACTIVE,
  18        NOHZ_MODE_LOWRES,
  19        NOHZ_MODE_HIGHRES,
  20};
  21
  22/**
  23 * struct tick_sched - sched tick emulation and no idle tick control/stats
  24 * @sched_timer:        hrtimer to schedule the periodic tick in high
  25 *                      resolution mode
  26 * @last_tick:          Store the last tick expiry time when the tick
  27 *                      timer is modified for nohz sleeps. This is necessary
  28 *                      to resume the tick timer operation in the timeline
  29 *                      when the CPU returns from nohz sleep.
  30 * @tick_stopped:       Indicator that the idle tick has been stopped
  31 * @idle_jiffies:       jiffies at the entry to idle for idle time accounting
  32 * @idle_calls:         Total number of idle calls
  33 * @idle_sleeps:        Number of idle calls, where the sched tick was stopped
  34 * @idle_entrytime:     Time when the idle call was entered
  35 * @idle_waketime:      Time when the idle was interrupted
  36 * @idle_exittime:      Time when the idle state was left
  37 * @idle_sleeptime:     Sum of the time slept in idle with sched tick stopped
  38 * @iowait_sleeptime:   Sum of the time slept in idle with sched tick stopped, with IO outstanding
  39 * @sleep_length:       Duration of the current idle sleep
  40 * @do_timer_lst:       CPU was the last one doing do_timer before going idle
  41 */
  42struct tick_sched {
  43        struct hrtimer                  sched_timer;
  44        unsigned long                   check_clocks;
  45        enum tick_nohz_mode             nohz_mode;
  46        ktime_t                         last_tick;
  47        int                             inidle;
  48        int                             tick_stopped;
  49        unsigned long                   idle_jiffies;
  50        unsigned long                   idle_calls;
  51        unsigned long                   idle_sleeps;
  52        int                             idle_active;
  53        ktime_t                         idle_entrytime;
  54        ktime_t                         idle_waketime;
  55        ktime_t                         idle_exittime;
  56        ktime_t                         idle_sleeptime;
  57        ktime_t                         iowait_sleeptime;
  58        ktime_t                         sleep_length;
  59        unsigned long                   last_jiffies;
  60        u64                             next_timer;
  61        ktime_t                         idle_expires;
  62        int                             do_timer_last;
  63        atomic_t                        tick_dep_mask;
  64};
  65
  66extern struct tick_sched *tick_get_tick_sched(int cpu);
  67
  68extern void tick_setup_sched_timer(void);
  69#if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
  70extern void tick_cancel_sched_timer(int cpu);
  71#else
  72static inline void tick_cancel_sched_timer(int cpu) { }
  73#endif
  74
  75#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  76extern int __tick_broadcast_oneshot_control(enum tick_broadcast_state state);
  77#else
  78static inline int
  79__tick_broadcast_oneshot_control(enum tick_broadcast_state state)
  80{
  81        return -EBUSY;
  82}
  83#endif
  84
  85#endif
  86