Commit 157d29e1 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

tick: Sched: Restructure code 



Get rid of one indentation level. Preparatory patch for a major
rework. No functional change.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Link: http://lkml.kernel.org/r/20150414203502.101563235@linutronix.de


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 0ff53d09

kernel/time/tick-sched.c

+81 −90
Original line number Diff line number Diff line
@@ -611,28 +611,26 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, 
		}

	}



	/*

	 * Do not stop the tick, if we are only one off (or less)

	 * or if the cpu is required for RCU:

	 */

	if (!ts->tick_stopped && delta_jiffies <= 1)

	if ((long)delta_jiffies <= 1) {

		if (!ts->tick_stopped)

			goto out;



	/* Schedule the tick, if we are at least one jiffie off */

	if ((long)delta_jiffies >= 1) {

		if (delta_jiffies == 0) {

			/* Tick is stopped, but required now. Enforce it */

			tick_nohz_restart(ts, now);

			goto out;

		}

	}



	/*

		 * If this cpu is the one which updates jiffies, then

		 * give up the assignment and let it be taken by the

		 * cpu which runs the tick timer next, which might be

		 * this cpu as well. If we don't drop this here the

		 * jiffies might be stale and do_timer() never

		 * invoked. Keep track of the fact that it was the one

		 * which had the do_timer() duty last. If this cpu is

		 * the one which had the do_timer() duty last, we

		 * limit the sleep time to the timekeeping

		 * max_deferement value which we retrieved

		 * above. Otherwise we can sleep as long as we want.

	 * If this cpu is the one which updates jiffies, then give up

	 * the assignment and let it be taken by the cpu which runs

	 * the tick timer next, which might be this cpu as well. If we

	 * don't drop this here the jiffies might be stale and

	 * do_timer() never invoked. Keep track of the fact that it

	 * was the one which had the do_timer() duty last. If this cpu

	 * is the one which had the do_timer() duty last, we limit the

	 * sleep time to the timekeeping max_deferement value which we

	 * retrieved above. Otherwise we can sleep as long as we want.

	 */

	if (cpu == tick_do_timer_cpu) {

		tick_do_timer_cpu = TICK_DO_TIMER_NONE;
@@ -645,18 +643,16 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, 
	}



#ifdef CONFIG_NO_HZ_FULL

		if (!ts->inidle) {

			time_delta = min(time_delta,

					 scheduler_tick_max_deferment());

		}

	if (!ts->inidle)

		time_delta = min(time_delta, scheduler_tick_max_deferment());

#endif



	/*

	 * calculate the expiry time for the next timer wheel

		 * timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals

		 * that there is no timer pending or at least extremely

		 * far into the future (12 days for HZ=1000). In this

		 * case we set the expiry to the end of time.

	 * timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals that

	 * there is no timer pending or at least extremely far into

	 * the future (12 days for HZ=1000). In this case we set the

	 * expiry to the end of time.

	 */

	if (likely(delta_jiffies < NEXT_TIMER_MAX_DELTA)) {

		/*
@@ -712,11 +708,6 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, 
			      HRTIMER_MODE_ABS_PINNED);

	else

		tick_program_event(expires, 1);

	} else {

		/* Tick is stopped, but required now. Enforce it */

		tick_nohz_restart(ts, now);

	}



out:

	ts->next_jiffies = next_jiffies;

	ts->last_jiffies = last_jiffies;