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| author | Thomas Gleixner <tglx@linutronix.de> | 2015-04-14 21:08:58 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2015-04-22 17:06:50 +0200 |
| commit | c1ad348b452aacd784fb97403d03d71723c72ee1 (patch) | |
| tree | 8f57456095d7125463a9647701acfe24b9d96ffc /include/linux/timer.h | |
| parent | 157d29e101c7d032e886df067aeea1b21a366cc5 (diff) | |
| download | lwn-c1ad348b452aacd784fb97403d03d71723c72ee1.tar.gz lwn-c1ad348b452aacd784fb97403d03d71723c72ee1.zip | |
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 <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Link: http://lkml.kernel.org/r/20150414203502.184198593@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/timer.h')
| -rw-r--r-- | include/linux/timer.h | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/include/linux/timer.h b/include/linux/timer.h index 8c5a197e1587..fbb80e0030bf 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -188,13 +188,6 @@ extern void set_timer_slack(struct timer_list *time, int slack_hz); #define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1) /* - * Return when the next timer-wheel timeout occurs (in absolute jiffies), - * locks the timer base and does the comparison against the given - * jiffie. - */ -extern unsigned long get_next_timer_interrupt(unsigned long now); - -/* * Timer-statistics info: */ #ifdef CONFIG_TIMER_STATS |