Re: [tip:sched/core] sched: Untangle cpu-load and timekeeping code

[Yong Zhang]

On Thu, Jan 27, 2011 at 4:03 AM, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
>> We should not do this checking any more. In normal case,
>> it will always return false.
>> If it indeed returns true for some reason, we will lose the
>> timer forever.
>
> Its needed for the nohz case, arguably we could move it inside
> calc_global_nohz().

I have no idea why we need that checking in  calc_global_nohz().

Before this patch, time_before(jiffies, calc_load_update) is
needed in calc_global_nohz() because it will reduce the ovehead
on dealing with calc_load_fold_idle if we have idle dance in one
LOAD_FREQ.

Now we have calc_global_load() called at every LOAD_FREQ
instead of every tick, that problem is gone.

But maybe I have missed something ;)

Thanks,
Yong


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