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timers/nohz: Remove pointless tick_nohz_kick_tick() function

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This was a failed attempt to optimize the timer expiry in idle, which was
disabled and never revisited. Remove the cruft.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160704094342.431073782@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Thomas Gleixner 2016-07-04 09:50:35 +00:00 committed by Ingo Molnar
parent 236968383c
commit ff00673292
1 changed files with 1 additions and 32 deletions
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33
kernel/time/tick-sched.c
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@ -1092,35 +1092,6 @@ static void tick_nohz_switch_to_nohz(void)
tick_nohz_activate(ts, NOHZ_MODE_LOWRES);
}
/*
* When NOHZ is enabled and the tick is stopped, we need to kick the
* tick timer from irq_enter() so that the jiffies update is kept
* alive during long running softirqs. That's ugly as hell, but
* correctness is key even if we need to fix the offending softirq in
* the first place.
*
* Note, this is different to tick_nohz_restart. We just kick the
* timer and do not touch the other magic bits which need to be done
* when idle is left.
*/
static void tick_nohz_kick_tick(struct tick_sched *ts, ktime_t now)
{
#if 0
/* Switch back to 2.6.27 behaviour */
ktime_t delta;
/*
* Do not touch the tick device, when the next expiry is either
* already reached or less/equal than the tick period.
*/
delta = ktime_sub(hrtimer_get_expires(&ts->sched_timer), now);
if (delta.tv64 <= tick_period.tv64)
return;
tick_nohz_restart(ts, now);
#endif
}
static inline void tick_nohz_irq_enter(void)
{
struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
@ -1131,10 +1102,8 @@ static inline void tick_nohz_irq_enter(void)
now = ktime_get();
if (ts->idle_active)
tick_nohz_stop_idle(ts, now);
if (ts->tick_stopped) {
if (ts->tick_stopped)
tick_nohz_update_jiffies(now);
tick_nohz_kick_tick(ts, now);
}
}
#else