Messages in this thread Patch in this message | | | From | Peng Liu <> | Subject | [PATCH v2 2/2] tick/nohz: Remove duplicate between tick_nohz_lowres_handler() and tick_nohz_highres_handler() | Date | Tue, 28 Nov 2023 17:24:13 +0800 |
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From: Peng Liu <liupeng17@lenovo.com>
tick_nohz_lowres_handler() does the same work as tick_nohz_highres_handler() plus the clockevent device reprogramming, so should reuse the latter.
Signed-off-by: Peng Liu <liupeng17@lenovo.com> --- Changes in v2: - Fix build warning: Function parameter or member 'mode' not described in 'tick_setup_sched_timer' - Fix build error: use of undeclared identifier 'tick_nohz_highres_handler' - Fix build error: use of undeclared identifier 'sched_skew_tick' --- kernel/time/tick-sched.c | 28 ++++++---------------------- 1 file changed, 6 insertions(+), 22 deletions(-)
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 96fcf5cb1b49..c2142b38c31d 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -1383,36 +1383,25 @@ void tick_nohz_idle_exit(void) local_irq_enable(); } +static enum hrtimer_restart tick_nohz_highres_handler(struct hrtimer *timer); + /* * In low-resolution mode, the tick handler must be implemented directly * 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. + * This low-resolution handler still reuse tick_nohz_highres_handler() since + * most of the work is independent of the clockevent level. */ 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_highres_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) @@ -1481,10 +1470,7 @@ void tick_irq_enter(void) tick_nohz_irq_enter(); } -/* - * High resolution timer specific code - */ -#ifdef CONFIG_HIGH_RES_TIMERS +#if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS /* * We rearm the timer until we get disabled by the idle code. * Called with interrupts disabled. @@ -1519,9 +1505,7 @@ static enum hrtimer_restart tick_nohz_highres_handler(struct hrtimer *timer) return HRTIMER_RESTART; } -#endif /* HIGH_RES_TIMERS */ -#if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS static int sched_skew_tick; static int __init skew_tick(char *str) -- 2.34.1
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