From c1ad348b452aacd784fb97403d03d71723c72ee1 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 14 Apr 2015 21:08:58 +0000 Subject: tick: Nohz: Rework next timer evaluation The evaluation of the next timer in the nohz code is based on jiffies while all the tick internals are nano seconds based. We have also to convert hrtimer nanoseconds to jiffies in the !highres case. That's just wrong and introduces interesting corner cases. Turn it around and convert the next timer wheel timer expiry and the rcu event to clock monotonic and base all calculations on nanoseconds. That identifies the case where no timer is pending clearly with an absolute expiry value of KTIME_MAX. Makes the code more readable and gets rid of the jiffies magic in the nohz code. Signed-off-by: Thomas Gleixner Reviewed-by: Paul E. McKenney Acked-by: Peter Zijlstra Cc: Preeti U Murthy Cc: Viresh Kumar Cc: Marcelo Tosatti Cc: Frederic Weisbecker Cc: Josh Triplett Cc: Lai Jiangshan Cc: John Stultz Cc: Marcelo Tosatti Link: http://lkml.kernel.org/r/20150414203502.184198593@linutronix.de Signed-off-by: Thomas Gleixner --- kernel/time/tick-sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/time/tick-sched.h') diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h index 28b5da3e1a17..42fdf4958bcc 100644 --- a/kernel/time/tick-sched.h +++ b/kernel/time/tick-sched.h @@ -57,7 +57,7 @@ struct tick_sched { ktime_t iowait_sleeptime; ktime_t sleep_length; unsigned long last_jiffies; - unsigned long next_jiffies; + u64 next_timer; ktime_t idle_expires; int do_timer_last; }; -- cgit v1.2.3