kernel/time/tick-sched.h

   1 #ifndef _TICK_SCHED_H
   2 #define _TICK_SCHED_H
   3
   4 #include <linux/hrtimer.h>
   5
   6 enum tick_device_mode {
   7         TICKDEV_MODE_PERIODIC,
   8         TICKDEV_MODE_ONESHOT,
   9 };
  10
  11 struct tick_device {
  12         struct clock_event_device *evtdev;
  13         enum tick_device_mode mode;
  14 };
  15
  16 enum 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  */
  42 struct 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
  66 extern struct tick_sched *tick_get_tick_sched(int cpu);
  67
  68 extern void tick_setup_sched_timer(void);
  69 #if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
  70 extern void tick_cancel_sched_timer(int cpu);
  71 #else
  72 static inline void tick_cancel_sched_timer(int cpu) { }
  73 #endif
  74
  75 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  76 extern int __tick_broadcast_oneshot_control(enum tick_broadcast_state state);
  77 #else
  78 static inline int
  79 __tick_broadcast_oneshot_control(enum tick_broadcast_state state)
  80 {
  81         return -EBUSY;
  82 }
  83 #endif
  84
  85 #endif