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 extern void tick_freeze(void); 83 extern void tick_unfreeze(void); 84 85 # ifdef CONFIG_HIGH_RES_TIMERS 86 extern int tick_init_highres(void); 87 extern int tick_program_event(ktime_t expires, int force); 88 extern void tick_setup_sched_timer(void); 89 # endif 90 91 # if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS 92 extern void tick_cancel_sched_timer(int cpu); 93 # else 94 static inline void tick_cancel_sched_timer(int cpu) { } 95 # endif 96 97 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 98 extern struct tick_device *tick_get_broadcast_device(void); 99 extern struct cpumask *tick_get_broadcast_mask(void); 100 101 # ifdef CONFIG_TICK_ONESHOT 102 extern struct cpumask *tick_get_broadcast_oneshot_mask(void); 103 # endif 104 105 # endif /* BROADCAST */ 106 107 # ifdef CONFIG_TICK_ONESHOT 108 extern void tick_clock_notify(void); 109 extern int tick_check_oneshot_change(int allow_nohz); 110 extern struct tick_sched *tick_get_tick_sched(int cpu); 111 extern void tick_irq_enter(void); 112 extern int tick_oneshot_mode_active(void); 113 # ifndef arch_needs_cpu 114 # define arch_needs_cpu() (0) 115 # endif 116 # else 117 static inline void tick_clock_notify(void) { } 118 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 119 static inline void tick_irq_enter(void) { } 120 static inline int tick_oneshot_mode_active(void) { return 0; } 121 # endif 122 123 #else /* CONFIG_GENERIC_CLOCKEVENTS */ 124 static inline void tick_init(void) { } 125 static inline void tick_freeze(void) { } 126 static inline void tick_unfreeze(void) { } 127 static inline void tick_cancel_sched_timer(int cpu) { } 128 static inline void tick_clock_notify(void) { } 129 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } 130 static inline void tick_irq_enter(void) { } 131 static inline int tick_oneshot_mode_active(void) { return 0; } 132 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ 133 134 # ifdef CONFIG_NO_HZ_COMMON 135 DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched); 136 137 static inline int tick_nohz_tick_stopped(void) 138 { 139 return __this_cpu_read(tick_cpu_sched.tick_stopped); 140 } 141 142 extern void tick_nohz_idle_enter(void); 143 extern void tick_nohz_idle_exit(void); 144 extern void tick_nohz_irq_exit(void); 145 extern ktime_t tick_nohz_get_sleep_length(void); 146 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); 147 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); 148 149 # else /* !CONFIG_NO_HZ_COMMON */ 150 static inline int tick_nohz_tick_stopped(void) 151 { 152 return 0; 153 } 154 155 static inline void tick_nohz_idle_enter(void) { } 156 static inline void tick_nohz_idle_exit(void) { } 157 158 static inline ktime_t tick_nohz_get_sleep_length(void) 159 { 160 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ }; 161 162 return len; 163 } 164 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; } 165 static 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 169 extern bool tick_nohz_full_running; 170 extern cpumask_var_t tick_nohz_full_mask; 171 extern cpumask_var_t housekeeping_mask; 172 173 static 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 } 180 181 static 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 } 188 189 extern void __tick_nohz_full_check(void); 190 extern void tick_nohz_full_kick(void); 191 extern void tick_nohz_full_kick_cpu(int cpu); 192 extern void tick_nohz_full_kick_all(void); 193 extern void __tick_nohz_task_switch(struct task_struct *tsk); 194 #else 195 static inline bool tick_nohz_full_enabled(void) { return false; } 196 static inline bool tick_nohz_full_cpu(int cpu) { return false; } 197 static inline void __tick_nohz_full_check(void) { } 198 static inline void tick_nohz_full_kick_cpu(int cpu) { } 199 static inline void tick_nohz_full_kick(void) { } 200 static inline void tick_nohz_full_kick_all(void) { } 201 static inline void __tick_nohz_task_switch(struct task_struct *tsk) { } 202 #endif 203 204 static 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 } 212 213 static 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 } 221 222 static inline void tick_nohz_full_check(void) 223 { 224 if (tick_nohz_full_enabled()) 225 __tick_nohz_full_check(); 226 } 227 228 static 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 235