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Date: Wed, 15 May 2024 12:13:05 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Mike Galbraith <efault@gmx.de>
Cc: mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org,
	dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com,
	mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com,
	linux-kernel@vger.kernel.org, kprateek.nayak@amd.com,
	wuyun.abel@bytedance.com, tglx@linutronix.de
Subject: Re: [RFC][PATCH 10/10] sched/eevdf: Use sched_attr::sched_runtime to
 set request/slice suggestion
Message-ID: <20240515101305.GG40213@noisy.programming.kicks-ass.net>
References: <20240405102754.435410987@infradead.org>
 <20240405110010.934104715@infradead.org>
 <22b6408d96ce3913121a4a1b80f343657d1f66ae.camel@gmx.de>
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In-Reply-To: <22b6408d96ce3913121a4a1b80f343657d1f66ae.camel@gmx.de>

On Tue, May 07, 2024 at 07:34:54AM +0200, Mike Galbraith wrote:
> On Fri, 2024-04-05 at 12:28 +0200, Peter Zijlstra wrote:
> > 
> > --- a/kernel/sched/core.c
> > +++ b/kernel/sched/core.c
> > @@ -7812,7 +7823,9 @@ static int __sched_setscheduler(struct t
> > ???????? * but store a possible modification of reset_on_fork.
> > ???????? */
> > ????????if (unlikely(policy == p->policy)) {
> > -???????????????if (fair_policy(policy) && attr->sched_nice != task_nice(p))
> > +???????????????if (fair_policy(policy) &&
> > +?????????????????? (attr->sched_nice != task_nice(p) ||
> > +??????????????????? (attr->sched_runtime && attr->sched_runtime != p->se.slice)))
> > ????????????????????????goto change;
> 
> Can we make that only look at attr->sched_runtime != p->se.slice? 
> Doing so lets you clear a custom slice by.. clearing it.. rather than
> making tools rummage about for the proper value to overwrite.

Duh yes. Seems I already did the right thing in __setscheduler_params()
for that.

Done.