Re: [PATCH 00/19] sched: Core Scheduling

[Peter Zijlstra]

On Thu, Apr 22, 2021 at 09:43:59AM -0700, Don Hiatt wrote:
> On Thu, Apr 22, 2021 at 5:37 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> >
> > Hai,
> >
> > This is an agressive fold of all the core-scheduling work so far. I've stripped
> > a whole bunch of tags along the way (hopefully not too many, please yell if you
> > feel I made a mistake), including tested-by. Please retest.
> >
> > Changes since the last partial post is dropping all the cgroup stuff and
> > PR_SCHED_CORE_CLEAR as well as that exec() behaviour in order to later resolve
> > the cgroup issue.
> >
> Hi Peter,
> 
> Is there a reason that PR_SCHED_CORE_CLEAR got removed? It's handy to
> be able to clear cookies.

I agree, but if we're forced to do cgroup with cookie inherit, when
CLEAR allows a trivial escape.

Until that whole cgroup thing is sorted, it is easiest to not have
CLEAR, lest we have to change/augment CLEAR semantics in unfortunate
ways, which is always harder once an API is out there.

Also, see the entire previous discussion here:

  https://lore.kernel.org/lkml/20210401131012.395311786@xxxxxxxxxxxxx/