nohz: reduce jiffies polling overhead

Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar 2008-05-12 15:43:53 +02:00
parent 916941b2bf
commit 7a14ce1d8c

View file

@ -48,6 +48,13 @@ static void tick_do_update_jiffies64(ktime_t now)
unsigned long ticks = 0;
ktime_t delta;
/*
* Do a quick check without holding xtime_lock:
*/
delta = ktime_sub(now, last_jiffies_update);
if (delta.tv64 < tick_period.tv64)
return;
/* Reevalute with xtime_lock held */
write_seqlock(&xtime_lock);