Re: [PATCH v2 00/13] sched/fair/schedutil: Better manage system response time

[Qais Yousef <qyousef@layalina.io>]

On 05/11/26 10:58, John Stultz wrote:
> On Sun, May 3, 2026 at 7:00 PM Qais Yousef <qyousef@layalina.io> wrote:
> >
> > This is the long delayed follow up to the series sent back in August 2024 [1].
> > Life got in the way to some extent (I had a baby, and now my time that I used
> > to do upstream work late at night was stolen :). Apologies for those who
> > replied and I didn't get a chance to respond back.
> >
> ...
> > Open questions:
> >
> > * The details of the QoS interface is the biggest one.
> > * Would debugfs be better for setting the default rampup multiplier instead of sysctl?
> > * Patch 13 makes updating load_avg unconditional not on period boundaries.
> >
> > Patches 1-3 are prepatory patches renaming a function and introducing new ones.
> >
> > Patches 4-5 handle the magic margin problem but making them dynamic based on
> > actual hardware limitations.
> >
> > Patches 6-7 fix the black hole problem and teaches the scheduler how to handle
> > bursty and periodic tasks via extending util_est.
> >
> > Patches 8-9 is where I expect most of the discussion on as I introduce a new
> > sched_qos interface to support the new rampup_multiplier to help manage DVFS.
> >
> > Patches 10-11 introduces a couple of necessary optimizations to counter the
> > power impact of increased responsiveness by disabling some features that we now
> > know how to handle better.
> >
> > Patches 12-13 fix a couple of issues causing util_est and util_avg value to
> > swing for a periodic task. Patch 12 must go via stable.
> 
> Just a minor nit, If 12/13 are fixes, should they not be at the front
> of the series (or possibly sent separately) so they can potentially
> move forward while the bigger changes in this series are discussed?

Yeah  my plan was to split it and repost it with proper Fixes tag. I found it
while verifying my patches so lumped it at the end. Will repost as soon as
I can.