1 /* linux/include/linux/tick.h
3 * This file contains the structure definitions for tick related functions
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>
17 #ifdef CONFIG_GENERIC_CLOCKEVENTS
19 enum tick_device_mode
{
20 TICKDEV_MODE_PERIODIC
,
25 struct clock_event_device
*evtdev
;
26 enum tick_device_mode mode
;
36 * struct tick_sched - sched tick emulation and no idle tick control/stats
37 * @sched_timer: hrtimer to schedule the periodic tick in high
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
56 struct hrtimer sched_timer
;
57 unsigned long check_clocks
;
58 enum tick_nohz_mode nohz_mode
;
62 unsigned long idle_jiffies
;
63 unsigned long idle_calls
;
64 unsigned long idle_sleeps
;
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
;
72 unsigned long last_jiffies
;
73 unsigned long next_jiffies
;
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
);
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);
88 # if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
89 extern void tick_cancel_sched_timer(int cpu
);
91 static inline void tick_cancel_sched_timer(int cpu
) { }
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);
98 # ifdef CONFIG_TICK_ONESHOT
99 extern struct cpumask
*tick_get_broadcast_oneshot_mask(void);
102 # endif /* BROADCAST */
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() (0)
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; }
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 */
129 # ifdef CONFIG_NO_HZ_COMMON
130 DECLARE_PER_CPU(struct tick_sched
, tick_cpu_sched
);
132 static inline int tick_nohz_tick_stopped(void)
134 return __this_cpu_read(tick_cpu_sched
.tick_stopped
);
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
);
144 # else /* !CONFIG_NO_HZ_COMMON */
145 static inline int tick_nohz_tick_stopped(void)
150 static inline void tick_nohz_idle_enter(void) { }
151 static inline void tick_nohz_idle_exit(void) { }
153 static inline ktime_t
tick_nohz_get_sleep_length(void)
155 ktime_t len
= { .tv64
= NSEC_PER_SEC
/HZ
};
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 */
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
;
168 static inline bool tick_nohz_full_enabled(void)
170 if (!context_tracking_is_enabled())
173 return tick_nohz_full_running
;
176 static inline bool tick_nohz_full_cpu(int cpu
)
178 if (!tick_nohz_full_enabled())
181 return cpumask_test_cpu(cpu
, tick_nohz_full_mask
);
184 extern void __tick_nohz_full_check(void);
185 extern void tick_nohz_full_kick(void);
186 extern void tick_nohz_full_kick_cpu(int cpu
);
187 extern void tick_nohz_full_kick_all(void);
188 extern void __tick_nohz_task_switch(struct task_struct
*tsk
);
190 static inline bool tick_nohz_full_enabled(void) { return false; }
191 static inline bool tick_nohz_full_cpu(int cpu
) { return false; }
192 static inline void __tick_nohz_full_check(void) { }
193 static inline void tick_nohz_full_kick_cpu(int cpu
) { }
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
) { }
199 static inline bool is_housekeeping_cpu(int cpu
)
201 #ifdef CONFIG_NO_HZ_FULL
202 if (tick_nohz_full_enabled())
203 return cpumask_test_cpu(cpu
, housekeeping_mask
);
208 static inline void housekeeping_affine(struct task_struct
*t
)
210 #ifdef CONFIG_NO_HZ_FULL
211 if (tick_nohz_full_enabled())
212 set_cpus_allowed_ptr(t
, housekeeping_mask
);
217 static inline void tick_nohz_full_check(void)
219 if (tick_nohz_full_enabled())
220 __tick_nohz_full_check();
223 static inline void tick_nohz_task_switch(struct task_struct
*tsk
)
225 if (tick_nohz_full_enabled())
226 __tick_nohz_task_switch(tsk
);