Commit-ID: 4e85876a9d2a977b4a07389da8c07edf76d10825 Gitweb: http://git.kernel.org/tip/4e85876a9d2a977b4a07389da8c07edf76d10825 Author: Thomas Gleixner <[email protected]> AuthorDate: Mon, 4 Jul 2016 09:50:37 +0000 Committer: Ingo Molnar <[email protected]> CommitDate: Thu, 7 Jul 2016 10:35:11 +0200
timers: Only wake softirq if necessary With the wheel forwading in place and with the HZ=1000 4ms folding we can avoid running the softirq at all. Signed-off-by: Thomas Gleixner <[email protected]> Cc: Arjan van de Ven <[email protected]> Cc: Chris Mason <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: George Spelvin <[email protected]> Cc: Josh Triplett <[email protected]> Cc: Len Brown <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- kernel/time/timer.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 9339d71..8d830f1 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1608,7 +1608,18 @@ static void run_timer_softirq(struct softirq_action *h) */ void run_local_timers(void) { + struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]); + hrtimer_run_queues(); + /* Raise the softirq only if required. */ + if (time_before(jiffies, base->clk)) { + if (!IS_ENABLED(CONFIG_NO_HZ_COMMON) || !base->nohz_active) + return; + /* CPU is awake, so check the deferrable base. */ + base++; + if (time_before(jiffies, base->clk)) + return; + } raise_softirq(TIMER_SOFTIRQ); }
