Linux kernel mirror (for testing)
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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
19enum tick_device_mode {
20 TICKDEV_MODE_PERIODIC,
21 TICKDEV_MODE_ONESHOT,
22};
23
24struct tick_device {
25 struct clock_event_device *evtdev;
26 enum tick_device_mode mode;
27};
28
29enum 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 */
55struct 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
78extern void __init tick_init(void);
79extern int tick_is_oneshot_available(void);
80extern struct tick_device *tick_get_device(int cpu);
81
82# ifdef CONFIG_HIGH_RES_TIMERS
83extern int tick_init_highres(void);
84extern int tick_program_event(ktime_t expires, int force);
85extern void tick_setup_sched_timer(void);
86# endif
87
88# if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
89extern void tick_cancel_sched_timer(int cpu);
90# else
91static inline void tick_cancel_sched_timer(int cpu) { }
92# endif
93
94# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
95extern struct tick_device *tick_get_broadcast_device(void);
96extern struct cpumask *tick_get_broadcast_mask(void);
97
98# ifdef CONFIG_TICK_ONESHOT
99extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
100# endif
101
102# endif /* BROADCAST */
103
104# ifdef CONFIG_TICK_ONESHOT
105extern void tick_clock_notify(void);
106extern int tick_check_oneshot_change(int allow_nohz);
107extern struct tick_sched *tick_get_tick_sched(int cpu);
108extern void tick_irq_enter(void);
109extern int tick_oneshot_mode_active(void);
110# ifndef arch_needs_cpu
111# define arch_needs_cpu() (0)
112# endif
113# else
114static inline void tick_clock_notify(void) { }
115static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
116static inline void tick_irq_enter(void) { }
117static inline int tick_oneshot_mode_active(void) { return 0; }
118# endif
119
120#else /* CONFIG_GENERIC_CLOCKEVENTS */
121static inline void tick_init(void) { }
122static inline void tick_cancel_sched_timer(int cpu) { }
123static inline void tick_clock_notify(void) { }
124static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
125static inline void tick_irq_enter(void) { }
126static inline int tick_oneshot_mode_active(void) { return 0; }
127#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
128
129# ifdef CONFIG_NO_HZ_COMMON
130DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched);
131
132static inline int tick_nohz_tick_stopped(void)
133{
134 return __this_cpu_read(tick_cpu_sched.tick_stopped);
135}
136
137extern void tick_nohz_idle_enter(void);
138extern void tick_nohz_idle_exit(void);
139extern void tick_nohz_irq_exit(void);
140extern ktime_t tick_nohz_get_sleep_length(void);
141extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
142extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
143
144# else /* !CONFIG_NO_HZ_COMMON */
145static inline int tick_nohz_tick_stopped(void)
146{
147 return 0;
148}
149
150static inline void tick_nohz_idle_enter(void) { }
151static inline void tick_nohz_idle_exit(void) { }
152
153static inline ktime_t tick_nohz_get_sleep_length(void)
154{
155 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
156
157 return len;
158}
159static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
160static 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
164extern bool tick_nohz_full_running;
165extern cpumask_var_t tick_nohz_full_mask;
166extern cpumask_var_t housekeeping_mask;
167
168static 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
176static 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
184extern void __tick_nohz_full_check(void);
185extern void tick_nohz_full_kick(void);
186extern void tick_nohz_full_kick_cpu(int cpu);
187extern void tick_nohz_full_kick_all(void);
188extern void __tick_nohz_task_switch(struct task_struct *tsk);
189#else
190static inline bool tick_nohz_full_enabled(void) { return false; }
191static inline bool tick_nohz_full_cpu(int cpu) { return false; }
192static inline void __tick_nohz_full_check(void) { }
193static inline void tick_nohz_full_kick_cpu(int cpu) { }
194static inline void tick_nohz_full_kick(void) { }
195static inline void tick_nohz_full_kick_all(void) { }
196static inline void __tick_nohz_task_switch(struct task_struct *tsk) { }
197#endif
198
199static 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
208static 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
217static inline void tick_nohz_full_check(void)
218{
219 if (tick_nohz_full_enabled())
220 __tick_nohz_full_check();
221}
222
223static 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