Commit 37263ba0 authored by Peng Liu's avatar Peng Liu Committed by Thomas Gleixner
Browse files

tick/nohz: Remove duplicate between lowres and highres handlers 



tick_nohz_lowres_handler() does the same work as
tick_nohz_highres_handler() plus the clockevent device reprogramming, so
make the former reuse the latter and rename it accordingly.

Signed-off-by: default avatarPeng Liu <liupeng17@lenovo.com>
Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240225225508.11587-3-frederic@kernel.org
parent ffb7e01c

kernel/time/tick-sched.c

+36 −60
Original line number Diff line number Diff line
@@ -255,6 +255,40 @@ static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs) 
	update_process_times(user_mode(regs));

	profile_tick(CPU_PROFILING);

}



/*

 * We rearm the timer until we get disabled by the idle code.

 * Called with interrupts disabled.

 */

static enum hrtimer_restart tick_nohz_handler(struct hrtimer *timer)

{

	struct tick_sched *ts =	container_of(timer, struct tick_sched, sched_timer);

	struct pt_regs *regs = get_irq_regs();

	ktime_t now = ktime_get();



	tick_sched_do_timer(ts, now);



	/*

	 * Do not call when we are not in IRQ context and have

	 * no valid 'regs' pointer

	 */

	if (regs)

		tick_sched_handle(ts, regs);

	else

		ts->next_tick = 0;



	/*

	 * In dynticks mode, tick reprogram is deferred:

	 * - to the idle task if in dynticks-idle

	 * - to IRQ exit if in full-dynticks.

	 */

	if (unlikely(ts->tick_stopped))

		return HRTIMER_NORESTART;



	hrtimer_forward(timer, now, TICK_NSEC);



	return HRTIMER_RESTART;

}

#endif



#ifdef CONFIG_NO_HZ_FULL
@@ -1429,33 +1463,17 @@ void tick_nohz_idle_exit(void) 
 * at the clockevent level. hrtimer can't be used instead, because its

 * infrastructure actually relies on the tick itself as a backend in

 * low-resolution mode (see hrtimer_run_queues()).

 *

 * This low-resolution handler still makes use of some hrtimer APIs meanwhile

 * for convenience with expiration calculation and forwarding.

 */

static void tick_nohz_lowres_handler(struct clock_event_device *dev)

{

	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);

	struct pt_regs *regs = get_irq_regs();

	ktime_t now = ktime_get();



	dev->next_event = KTIME_MAX;



	tick_sched_do_timer(ts, now);

	tick_sched_handle(ts, regs);



	/*

	 * In dynticks mode, tick reprogram is deferred:

	 * - to the idle task if in dynticks-idle

	 * - to IRQ exit if in full-dynticks.

	 */

	if (likely(!ts->tick_stopped)) {

		hrtimer_forward(&ts->sched_timer, now, TICK_NSEC);

	if (likely(tick_nohz_handler(&ts->sched_timer) == HRTIMER_RESTART))

		tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1);

}



}



static inline void tick_nohz_activate(struct tick_sched *ts, int mode)

{

	if (!tick_nohz_enabled)
@@ -1522,48 +1540,6 @@ void tick_irq_enter(void) 
	tick_nohz_irq_enter();

}



/*

 * High resolution timer specific code

 */

#ifdef CONFIG_HIGH_RES_TIMERS

/*

 * We rearm the timer until we get disabled by the idle code.

 * Called with interrupts disabled.

 */

static enum hrtimer_restart tick_nohz_highres_handler(struct hrtimer *timer)

{

	struct tick_sched *ts =

		container_of(timer, struct tick_sched, sched_timer);

	struct pt_regs *regs = get_irq_regs();

	ktime_t now = ktime_get();



	tick_sched_do_timer(ts, now);



	/*

	 * Do not call when we are not in IRQ context and have

	 * no valid 'regs' pointer

	 */

	if (regs)

		tick_sched_handle(ts, regs);

	else

		ts->next_tick = 0;



	/*

	 * In dynticks mode, tick reprogram is deferred:

	 * - to the idle task if in dynticks-idle

	 * - to IRQ exit if in full-dynticks.

	 */

	if (unlikely(ts->tick_stopped))

		return HRTIMER_NORESTART;



	hrtimer_forward(timer, now, TICK_NSEC);



	return HRTIMER_RESTART;

}

#else

#define tick_nohz_highres_handler NULL

#endif /* CONFIG_HIGH_RES_TIMERS */



#if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS

static int sched_skew_tick;
@@ -1587,7 +1563,7 @@ void tick_setup_sched_timer(int mode) 
	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);



	if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS) && mode == NOHZ_MODE_HIGHRES)

		ts->sched_timer.function = tick_nohz_highres_handler;

		ts->sched_timer.function = tick_nohz_handler;



	/* Get the next period (per-CPU) */

	hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update());