Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
82extern void tick_freeze(void);
83extern void tick_unfreeze(void);
84
85# ifdef CONFIG_HIGH_RES_TIMERS
86extern int tick_init_highres(void);
87extern int tick_program_event(ktime_t expires, int force);
88extern void tick_setup_sched_timer(void);
89# endif
90
91# if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
92extern void tick_cancel_sched_timer(int cpu);
93# else
94static inline void tick_cancel_sched_timer(int cpu) { }
95# endif
96
97# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
98extern struct tick_device *tick_get_broadcast_device(void);
99extern struct cpumask *tick_get_broadcast_mask(void);
100
101# ifdef CONFIG_TICK_ONESHOT
102extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
103# endif
104
105# endif /* BROADCAST */
106
107# ifdef CONFIG_TICK_ONESHOT
108extern void tick_clock_notify(void);
109extern int tick_check_oneshot_change(int allow_nohz);
110extern struct tick_sched *tick_get_tick_sched(int cpu);
111extern void tick_irq_enter(void);
112extern int tick_oneshot_mode_active(void);
113# ifndef arch_needs_cpu
114# define arch_needs_cpu() (0)
115# endif
116# else
117static inline void tick_clock_notify(void) { }
118static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
119static inline void tick_irq_enter(void) { }
120static inline int tick_oneshot_mode_active(void) { return 0; }
121# endif
122
123#else /* CONFIG_GENERIC_CLOCKEVENTS */
124static inline void tick_init(void) { }
125static inline void tick_freeze(void) { }
126static inline void tick_unfreeze(void) { }
127static inline void tick_cancel_sched_timer(int cpu) { }
128static inline void tick_clock_notify(void) { }
129static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
130static inline void tick_irq_enter(void) { }
131static inline int tick_oneshot_mode_active(void) { return 0; }
132#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
133
134# ifdef CONFIG_NO_HZ_COMMON
135DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched);
136
137static inline int tick_nohz_tick_stopped(void)
138{
139 return __this_cpu_read(tick_cpu_sched.tick_stopped);
140}
141
142extern void tick_nohz_idle_enter(void);
143extern void tick_nohz_idle_exit(void);
144extern void tick_nohz_irq_exit(void);
145extern ktime_t tick_nohz_get_sleep_length(void);
146extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
147extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
148
149# else /* !CONFIG_NO_HZ_COMMON */
150static inline int tick_nohz_tick_stopped(void)
151{
152 return 0;
153}
154
155static inline void tick_nohz_idle_enter(void) { }
156static inline void tick_nohz_idle_exit(void) { }
157
158static inline ktime_t tick_nohz_get_sleep_length(void)
159{
160 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
161
162 return len;
163}
164static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
165static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
166# endif /* !CONFIG_NO_HZ_COMMON */
167
168#ifdef CONFIG_NO_HZ_FULL
169extern bool tick_nohz_full_running;
170extern cpumask_var_t tick_nohz_full_mask;
171extern cpumask_var_t housekeeping_mask;
172
173static inline bool tick_nohz_full_enabled(void)
174{
175 if (!context_tracking_is_enabled())
176 return false;
177
178 return tick_nohz_full_running;
179}
180
181static inline bool tick_nohz_full_cpu(int cpu)
182{
183 if (!tick_nohz_full_enabled())
184 return false;
185
186 return cpumask_test_cpu(cpu, tick_nohz_full_mask);
187}
188
189extern void __tick_nohz_full_check(void);
190extern void tick_nohz_full_kick(void);
191extern void tick_nohz_full_kick_cpu(int cpu);
192extern void tick_nohz_full_kick_all(void);
193extern void __tick_nohz_task_switch(struct task_struct *tsk);
194#else
195static inline bool tick_nohz_full_enabled(void) { return false; }
196static inline bool tick_nohz_full_cpu(int cpu) { return false; }
197static inline void __tick_nohz_full_check(void) { }
198static inline void tick_nohz_full_kick_cpu(int cpu) { }
199static inline void tick_nohz_full_kick(void) { }
200static inline void tick_nohz_full_kick_all(void) { }
201static inline void __tick_nohz_task_switch(struct task_struct *tsk) { }
202#endif
203
204static inline bool is_housekeeping_cpu(int cpu)
205{
206#ifdef CONFIG_NO_HZ_FULL
207 if (tick_nohz_full_enabled())
208 return cpumask_test_cpu(cpu, housekeeping_mask);
209#endif
210 return true;
211}
212
213static inline void housekeeping_affine(struct task_struct *t)
214{
215#ifdef CONFIG_NO_HZ_FULL
216 if (tick_nohz_full_enabled())
217 set_cpus_allowed_ptr(t, housekeeping_mask);
218
219#endif
220}
221
222static inline void tick_nohz_full_check(void)
223{
224 if (tick_nohz_full_enabled())
225 __tick_nohz_full_check();
226}
227
228static inline void tick_nohz_task_switch(struct task_struct *tsk)
229{
230 if (tick_nohz_full_enabled())
231 __tick_nohz_task_switch(tsk);
232}
233
234#endif