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

From: Peter Zijlstra
Date: Tue Dec 19 2017 - 13:48:33 EST


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:
> https://patchwork.kernel.org/patch/10115395/
> https://patchwork.kernel.org/patch/10115401/
> 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 have an absolutely stupid backlog :/