include/linux/tick.h

   1 /*  linux/include/linux/tick.h
   2  *
   3  *  This file contains the structure definitions for tick related functions
   4  *
   5  */
   6 #ifndef _LINUX_TICK_H
   7 #define _LINUX_TICK_H
   8
   9 #include <linux/clockchips.h>
  10 #include <linux/irqflags.h>
  11 #include <linux/percpu.h>
  12 #include <linux/hrtimer.h>
  13 #include <linux/context_tracking_state.h>
  14 #include <linux/cpumask.h>
  15 #include <linux/sched.h>
  16
  17 #ifdef CONFIG_GENERIC_CLOCKEVENTS
  18
  19 enum tick_device_mode {
  20         TICKDEV_MODE_PERIODIC,
  21         TICKDEV_MODE_ONESHOT,
  22 };
  23
  24 struct tick_device {
  25         struct clock_event_device *evtdev;
  26         enum tick_device_mode mode;
  27 };
  28
  29 enum tick_nohz_mode {
  30         NOHZ_MODE_INACTIVE,
  31         NOHZ_MODE_LOWRES,
  32         NOHZ_MODE_HIGHRES,
  33 };
  34
  35 /**
  36  * struct tick_sched - sched tick emulation and no idle tick control/stats
  37  * @sched_timer:        hrtimer to schedule the periodic tick in high
  38  *                      resolution mode
  39  * @last_tick:          Store the last tick expiry time when the tick
  40  *                      timer is modified for nohz sleeps. This is necessary
  41  *                      to resume the tick timer operation in the timeline
  42  *                      when the CPU returns from nohz sleep.
  43  * @tick_stopped:       Indicator that the idle tick has been stopped
  44  * @idle_jiffies:       jiffies at the entry to idle for idle time accounting
  45  * @idle_calls:         Total number of idle calls
  46  * @idle_sleeps:        Number of idle calls, where the sched tick was stopped
  47  * @idle_entrytime:     Time when the idle call was entered
  48  * @idle_waketime:      Time when the idle was interrupted
  49  * @idle_exittime:      Time when the idle state was left
  50  * @idle_sleeptime:     Sum of the time slept in idle with sched tick stopped
  51  * @iowait_sleeptime:   Sum of the time slept in idle with sched tick stopped, with IO outstanding
  52  * @sleep_length:       Duration of the current idle sleep
  53  * @do_timer_lst:       CPU was the last one doing do_timer before going idle
  54  */
  55 struct tick_sched {
  56         struct hrtimer                  sched_timer;
  57         unsigned long                   check_clocks;
  58         enum tick_nohz_mode             nohz_mode;
  59         ktime_t                         last_tick;
  60         int                             inidle;
  61         int                             tick_stopped;
  62         unsigned long                   idle_jiffies;
  63         unsigned long                   idle_calls;
  64         unsigned long                   idle_sleeps;
  65         int                             idle_active;
  66         ktime_t                         idle_entrytime;
  67         ktime_t                         idle_waketime;
  68         ktime_t                         idle_exittime;
  69         ktime_t                         idle_sleeptime;
  70         ktime_t                         iowait_sleeptime;
  71         ktime_t                         sleep_length;
  72         unsigned long                   last_jiffies;
  73         unsigned long                   next_jiffies;
  74         ktime_t                         idle_expires;
  75         int                             do_timer_last;
  76 };
  77
  78 extern void __init tick_init(void);
  79 extern int tick_is_oneshot_available(void);
  80 extern struct tick_device *tick_get_device(int cpu);
  81
  82 # ifdef CONFIG_HIGH_RES_TIMERS
  83 extern int tick_init_highres(void);
  84 extern int tick_program_event(ktime_t expires, int force);
  85 extern void tick_setup_sched_timer(void);
  86 # endif
  87
  88 # if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
  89 extern void tick_cancel_sched_timer(int cpu);
  90 # else
  91 static inline void tick_cancel_sched_timer(int cpu) { }
  92 # endif
  93
  94 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  95 extern struct tick_device *tick_get_broadcast_device(void);
  96 extern struct cpumask *tick_get_broadcast_mask(void);
  97
  98 #  ifdef CONFIG_TICK_ONESHOT
  99 extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
 100 #  endif
 101
 102 # endif /* BROADCAST */
 103
 104 # ifdef CONFIG_TICK_ONESHOT
 105 extern void tick_clock_notify(void);
 106 extern int tick_check_oneshot_change(int allow_nohz);
 107 extern struct tick_sched *tick_get_tick_sched(int cpu);
 108 extern void tick_irq_enter(void);
 109 extern int tick_oneshot_mode_active(void);
 110 #  ifndef arch_needs_cpu
 111 #   define arch_needs_cpu(cpu) (0)
 112 #  endif
 113 # else
 114 static inline void tick_clock_notify(void) { }
 115 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 116 static inline void tick_irq_enter(void) { }
 117 static inline int tick_oneshot_mode_active(void) { return 0; }
 118 # endif
 119
 120 #else /* CONFIG_GENERIC_CLOCKEVENTS */
 121 static inline void tick_init(void) { }
 122 static inline void tick_cancel_sched_timer(int cpu) { }
 123 static inline void tick_clock_notify(void) { }
 124 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 125 static inline void tick_irq_enter(void) { }
 126 static inline int tick_oneshot_mode_active(void) { return 0; }
 127 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
 128
 129 # ifdef CONFIG_NO_HZ_COMMON
 130 DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched);
 131
 132 static inline int tick_nohz_tick_stopped(void)
 133 {
 134         return __this_cpu_read(tick_cpu_sched.tick_stopped);
 135 }
 136
 137 extern void tick_nohz_idle_enter(void);
 138 extern void tick_nohz_idle_exit(void);
 139 extern void tick_nohz_irq_exit(void);
 140 extern ktime_t tick_nohz_get_sleep_length(void);
 141 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
 142 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
 143
 144 # else /* !CONFIG_NO_HZ_COMMON */
 145 static inline int tick_nohz_tick_stopped(void)
 146 {
 147         return 0;
 148 }
 149
 150 static inline void tick_nohz_idle_enter(void) { }
 151 static inline void tick_nohz_idle_exit(void) { }
 152
 153 static inline ktime_t tick_nohz_get_sleep_length(void)
 154 {
 155         ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
 156
 157         return len;
 158 }
 159 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
 160 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
 161 # endif /* !CONFIG_NO_HZ_COMMON */
 162
 163 #ifdef CONFIG_NO_HZ_FULL
 164 extern bool tick_nohz_full_running;
 165 extern cpumask_var_t tick_nohz_full_mask;
 166 extern cpumask_var_t housekeeping_mask;
 167
 168 static inline bool tick_nohz_full_enabled(void)
 169 {
 170         if (!context_tracking_is_enabled())
 171                 return false;
 172
 173         return tick_nohz_full_running;
 174 }
 175
 176 static inline bool tick_nohz_full_cpu(int cpu)
 177 {
 178         if (!tick_nohz_full_enabled())
 179                 return false;
 180
 181         return cpumask_test_cpu(cpu, tick_nohz_full_mask);
 182 }
 183
 184 extern void tick_nohz_init(void);
 185 extern void __tick_nohz_full_check(void);
 186 extern void tick_nohz_full_kick(void);
 187 extern void tick_nohz_full_kick_all(void);
 188 extern void __tick_nohz_task_switch(struct task_struct *tsk);
 189 #else
 190 static inline void tick_nohz_init(void) { }
 191 static inline bool tick_nohz_full_enabled(void) { return false; }
 192 static inline bool tick_nohz_full_cpu(int cpu) { return false; }
 193 static inline void __tick_nohz_full_check(void) { }
 194 static inline void tick_nohz_full_kick(void) { }
 195 static inline void tick_nohz_full_kick_all(void) { }
 196 static inline void __tick_nohz_task_switch(struct task_struct *tsk) { }
 197 #endif
 198
 199 static inline bool is_housekeeping_cpu(int cpu)
 200 {
 201 #ifdef CONFIG_NO_HZ_FULL
 202         if (tick_nohz_full_enabled())
 203                 return cpumask_test_cpu(cpu, housekeeping_mask);
 204 #endif
 205         return true;
 206 }
 207
 208 static inline void housekeeping_affine(struct task_struct *t)
 209 {
 210 #ifdef CONFIG_NO_HZ_FULL
 211         if (tick_nohz_full_enabled())
 212                 set_cpus_allowed_ptr(t, housekeeping_mask);
 213
 214 #endif
 215 }
 216
 217 static inline void tick_nohz_full_check(void)
 218 {
 219         if (tick_nohz_full_enabled())
 220                 __tick_nohz_full_check();
 221 }
 222
 223 static inline void tick_nohz_task_switch(struct task_struct *tsk)
 224 {
 225         if (tick_nohz_full_enabled())
 226                 __tick_nohz_task_switch(tsk);
 227 }
 228
 229
 230 #endif