Re: [PATCH 10/24] sched/uclamg: Handle delayed dequeue

From: Peter Zijlstra
Date: Tue Sep 10 2024 - 10:05:53 EST


On Tue, Sep 10, 2024 at 12:04:11PM +0100, Luis Machado wrote:
> I gave the above patch a try on our Android workload running on the Pixel 6 with a 6.8-based kernel.
>
> First I'd like to confirm that Dietmar's fix that was pushed to tip:sched/core (Fix util_est
> accounting for DELAY_DEQUEUE) helps bring the frequencies and power use down to more sensible levels.
>
> As for the above changes, unfortunately I'm seeing high frequencies and high power usage again. The
> pattern looks similar to what we observed with the uclamp inc/dec imbalance.

:-(

> I haven't investigated this in depth yet, but I'll go stare at some traces and the code, and hopefully
> something will ring bells.

So first thing to do is trace h_nr_delayed I suppose, in my own
(limited) testing that was mostly [0,1] correctly correlating to there
being a delayed task on the runqueue.

I'm assuming that removing the usage sites restores function?