linux/kernel/time/tick-sched.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _TICK_SCHED_H
#define _TICK_SCHED_H

#include <linux/hrtimer.h>

enum tick_device_mode { … };

struct tick_device { … };

/* The CPU is in the tick idle mode */
#define TS_FLAG_INIDLE …
/* The idle tick has been stopped */
#define TS_FLAG_STOPPED …
/*
 * Indicator that the CPU is actively in the tick idle mode;
 * it is reset during irq handling phases.
 */
#define TS_FLAG_IDLE_ACTIVE …
/* CPU was the last one doing do_timer before going idle */
#define TS_FLAG_DO_TIMER_LAST …
/* NO_HZ is enabled */
#define TS_FLAG_NOHZ …
/* High resolution tick mode */
#define TS_FLAG_HIGHRES …

/**
 * struct tick_sched - sched tick emulation and no idle tick control/stats
 *
 * @flags:		State flags gathering the TS_FLAG_* features
 * @got_idle_tick:	Tick timer function has run with @inidle set
 * @stalled_jiffies:	Number of stalled jiffies detected across ticks
 * @last_tick_jiffies:	Value of jiffies seen on last tick
 * @sched_timer:	hrtimer to schedule the periodic tick in high
 *			resolution mode
 * @last_tick:		Store the last tick expiry time when the tick
 *			timer is modified for nohz sleeps. This is necessary
 *			to resume the tick timer operation in the timeline
 *			when the CPU returns from nohz sleep.
 * @next_tick:		Next tick to be fired when in dynticks mode.
 * @idle_jiffies:	jiffies at the entry to idle for idle time accounting
 * @idle_waketime:	Time when the idle was interrupted
 * @idle_sleeptime_seq:	sequence counter for data consistency
 * @idle_entrytime:	Time when the idle call was entered
 * @last_jiffies:	Base jiffies snapshot when next event was last computed
 * @timer_expires_base:	Base time clock monotonic for @timer_expires
 * @timer_expires:	Anticipated timer expiration time (in case sched tick is stopped)
 * @next_timer:		Expiry time of next expiring timer for debugging purpose only
 * @idle_expires:	Next tick in idle, for debugging purpose only
 * @idle_calls:		Total number of idle calls
 * @idle_sleeps:	Number of idle calls, where the sched tick was stopped
 * @idle_exittime:	Time when the idle state was left
 * @idle_sleeptime:	Sum of the time slept in idle with sched tick stopped
 * @iowait_sleeptime:	Sum of the time slept in idle with sched tick stopped, with IO outstanding
 * @tick_dep_mask:	Tick dependency mask - is set, if someone needs the tick
 * @check_clocks:	Notification mechanism about clocksource changes
 */
struct tick_sched { … };

extern struct tick_sched *tick_get_tick_sched(int cpu);

extern void tick_setup_sched_timer(bool hrtimer);
#if defined CONFIG_TICK_ONESHOT
extern void tick_sched_timer_dying(int cpu);
#else
static inline void tick_sched_timer_dying(int cpu) { }
#endif

#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
extern int __tick_broadcast_oneshot_control(enum tick_broadcast_state state);
#else
static inline int
__tick_broadcast_oneshot_control(enum tick_broadcast_state state)
{
	return -EBUSY;
}
#endif

#endif