Re: [PATCH RESEND] cpufreq: schedutil: Use idle_calls counter of the remote CPU

From: Joel Fernandes
Date: Tue Dec 19 2017 - 14:32:17 EST

On Tue, Dec 19, 2017 at 10:48 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Tue, Dec 19, 2017 at 09:47:12AM -0800, Joel Fernandes wrote:
>> Since the recent remote cpufreq callback work, its possible that a cpufreq
>> update is triggered from a remote CPU. For single policies however, the current
>> code uses the local CPU when trying to determine if the remote sg_cpu entered
>> idle or is busy. This is incorrect. To remedy this, compare with the nohz tick
>> idle_calls counter of the remote CPU.
>> Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
>> Signed-off-by: Joel Fernandes <joelaf@xxxxxxxxxx>
> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>


>> ---
>> Just resending this which is cpufreq-related as requested by Rafael rebased
>> on linus/master.
>> The other 2 patches in my last series which can go in independent of this one are:
>> I'm still waiting on scheduler maintainers to comment on those. Unfortunately,
>> I haven't heard back anything yet since the last repost of those.
> Both of us have been somewhat preoccupied with that whole kaiser/pti
> thing the past few weeks.

I understand, thanks for taking time to look at it! Hopefully you're
Ok with the second one as well
( And this cap aware
one's been pretty beaten to death too: but let me know your
objections if any.

> I have an absolutely stupid backlog :/

I see. :/
I am thinking of spending more time reviewing fwiw and hopefully
helping relieve some of that burden. Happy to help in any other way as
well so let me/us know how we can help.


- Joel