kernel/time/tick-sched.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _TICK_SCHED_H
   3 #define _TICK_SCHED_H
   4
   5 #include <linux/hrtimer.h>
   6
   7 enum tick_device_mode {
   8         TICKDEV_MODE_PERIODIC,
   9         TICKDEV_MODE_ONESHOT,
  10 };
  11
  12 struct tick_device {
  13         struct clock_event_device *evtdev;
  14         enum tick_device_mode mode;
  15 };
  16
  17 enum tick_nohz_mode {
  18         NOHZ_MODE_INACTIVE,
  19         NOHZ_MODE_LOWRES,
  20         NOHZ_MODE_HIGHRES,
  21 };
  22
  23 /**
  24  * struct tick_sched - sched tick emulation and no idle tick control/stats
  25  * @sched_timer:        hrtimer to schedule the periodic tick in high
  26  *                      resolution mode
  27  * @last_tick:          Store the last tick expiry time when the tick
  28  *                      timer is modified for nohz sleeps. This is necessary
  29  *                      to resume the tick timer operation in the timeline
  30  *                      when the CPU returns from nohz sleep.
  31  * @next_tick:          Next tick to be fired when in dynticks mode.
  32  * @tick_stopped:       Indicator that the idle tick has been stopped
  33  * @idle_jiffies:       jiffies at the entry to idle for idle time accounting
  34  * @idle_calls:         Total number of idle calls
  35  * @idle_sleeps:        Number of idle calls, where the sched tick was stopped
  36  * @idle_entrytime:     Time when the idle call was entered
  37  * @idle_waketime:      Time when the idle was interrupted
  38  * @idle_exittime:      Time when the idle state was left
  39  * @idle_sleeptime:     Sum of the time slept in idle with sched tick stopped
  40  * @iowait_sleeptime:   Sum of the time slept in idle with sched tick stopped, with IO outstanding
  41  * @sleep_length:       Duration of the current idle sleep
  42  * @do_timer_lst:       CPU was the last one doing do_timer before going idle
  43  */
  44 struct tick_sched {
  45         struct hrtimer                  sched_timer;
  46         unsigned long                   check_clocks;
  47         enum tick_nohz_mode             nohz_mode;
  48         ktime_t                         last_tick;
  49         ktime_t                         next_tick;
  50         int                             inidle;
  51         int                             tick_stopped;
  52         unsigned long                   idle_jiffies;
  53         unsigned long                   idle_calls;
  54         unsigned long                   idle_sleeps;
  55         int                             idle_active;
  56         ktime_t                         idle_entrytime;
  57         ktime_t                         idle_waketime;
  58         ktime_t                         idle_exittime;
  59         ktime_t                         idle_sleeptime;
  60         ktime_t                         iowait_sleeptime;
  61         ktime_t                         sleep_length;
  62         unsigned long                   last_jiffies;
  63         u64                             next_timer;
  64         ktime_t                         idle_expires;
  65         int                             do_timer_last;
  66         atomic_t                        tick_dep_mask;
  67 };
  68
  69 extern struct tick_sched *tick_get_tick_sched(int cpu);
  70
  71 extern void tick_setup_sched_timer(void);
  72 #if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
  73 extern void tick_cancel_sched_timer(int cpu);
  74 #else
  75 static inline void tick_cancel_sched_timer(int cpu) { }
  76 #endif
  77
  78 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  79 extern int __tick_broadcast_oneshot_control(enum tick_broadcast_state state);
  80 #else
  81 static inline int
  82 __tick_broadcast_oneshot_control(enum tick_broadcast_state state)
  83 {
  84         return -EBUSY;
  85 }
  86 #endif
  87
  88 #endif