Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [RFC] Introduce greedy hrtimer walk on idle | Date | Fri, 23 Sep 2011 15:59:16 -0700 |
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Venkatesh Pallipadi <venki@google.com> writes: > > But, doing an exhaustive search for all softexpired timers, especially when > CPU is idle, has its advantages: > * it will result in less interruptions later (when CPU may be busy). > * it can reduce number of wakeups in cases where not yet expired timer in above description could be deleted before they expire. > * For timers resulting in task wakeups, doing wakeup on idle can improve the > overall efficiency of the system. It can also bring load balance/migration benefits.
Seems like a good idea in general.
> diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c > index ca6f7ab..8d3e287 100644 > --- a/arch/x86/kernel/process_64.c > +++ b/arch/x86/kernel/process_64.c > @@ -149,6 +149,8 @@ void cpu_idle(void) > preempt_enable_no_resched(); > schedule(); > preempt_disable(); > + if (sysctl_hrtimer_greedy_lookup) > + hrtimer_peek_ahead_timers();
So why is it a sysctl and not default?
-Andi
-- ak@linux.intel.com -- Speaking for myself only
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