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tick: Sched: Restructure code

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

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter 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: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner
2015-04-14 21:08:56 +00:00
parent 0ff53d0964
commit 157d29e101
1 changed files with 93 additions and 102 deletions
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55
kernel/time/tick-sched.c
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@ -611,28 +611,26 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
} }
} }
/* if ((long)delta_jiffies <= 1) {
* Do not stop the tick, if we are only one off (or less) if (!ts->tick_stopped)
* or if the cpu is required for RCU:
*/
if (!ts->tick_stopped && delta_jiffies <= 1)
goto out; goto out;
if (delta_jiffies == 0) {
/* Schedule the tick, if we are at least one jiffie off */ /* Tick is stopped, but required now. Enforce it */
if ((long)delta_jiffies >= 1) { tick_nohz_restart(ts, now);
goto out;
}
}
/* /*
* If this cpu is the one which updates jiffies, then * If this cpu is the one which updates jiffies, then give up
* give up the assignment and let it be taken by the * the assignment and let it be taken by the cpu which runs
* cpu which runs the tick timer next, which might be * the tick timer next, which might be this cpu as well. If we
* this cpu as well. If we don't drop this here the * don't drop this here the jiffies might be stale and
* jiffies might be stale and do_timer() never * do_timer() never invoked. Keep track of the fact that it
* invoked. Keep track of the fact that it was the one * was the one which had the do_timer() duty last. If this cpu
* which had the do_timer() duty last. If this cpu is * is the one which had the do_timer() duty last, we limit the
* the one which had the do_timer() duty last, we * sleep time to the timekeeping max_deferement value which we
* limit the sleep time to the timekeeping * retrieved above. Otherwise we can sleep as long as we want.
* max_deferement value which we retrieved
* above. Otherwise we can sleep as long as we want.
*/ */
if (cpu == tick_do_timer_cpu) { if (cpu == tick_do_timer_cpu) {
tick_do_timer_cpu = TICK_DO_TIMER_NONE; 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 #ifdef CONFIG_NO_HZ_FULL
if (!ts->inidle) { if (!ts->inidle)
time_delta = min(time_delta, time_delta = min(time_delta, scheduler_tick_max_deferment());
scheduler_tick_max_deferment());
}
#endif #endif
/* /*
* calculate the expiry time for the next timer wheel * calculate the expiry time for the next timer wheel
* timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals * timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals that
* that there is no timer pending or at least extremely * there is no timer pending or at least extremely far into
* far into the future (12 days for HZ=1000). In this * the future (12 days for HZ=1000). In this case we set the
* case we set the expiry to the end of time. * expiry to the end of time.
*/ */
if (likely(delta_jiffies < NEXT_TIMER_MAX_DELTA)) { 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); HRTIMER_MODE_ABS_PINNED);
else else
tick_program_event(expires, 1); tick_program_event(expires, 1);
} else {
/* Tick is stopped, but required now. Enforce it */
tick_nohz_restart(ts, now);
}
out: out:
ts->next_jiffies = next_jiffies; ts->next_jiffies = next_jiffies;
ts->last_jiffies = last_jiffies; ts->last_jiffies = last_jiffies;