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From:   Josh Don <joshdon@google.com>
Date:   Fri, 25 Jun 2021 17:35:57 -0700
Message-ID: <CABk29Ns1mV030CRtidLh42-tc-xZ8=-MWQjZs5+myZVyZpDeuw@mail.gmail.com>
Subject: Re: [PATCH] sched: cgroup SCHED_IDLE support
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Ingo Molnar <mingo@redhat.com>, Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Paul Turner <pjt@google.com>,
        David Rientjes <rientjes@google.com>,
        Oleg Rombakh <olegrom@google.com>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Steve Sistare <steven.sistare@oracle.com>,
        Tejun Heo <tj@kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
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On Fri, Jun 25, 2021 at 1:21 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Tue, Jun 08, 2021 at 04:11:32PM -0700, Josh Don wrote:
> > +static int se_is_idle(struct sched_entity *se)
> > +{
> > +     if (entity_is_task(se))
> > +             return task_has_idle_policy(task_of(se));
> > +     return cfs_rq_is_idle(group_cfs_rq(se));
> > +}
>
> I'm conflicted on this, on the one hand, since we want 'idle' to be a
> sched_entity propery, I'd say, make it a sched_entity field, OTOH,
> that's probably going to be a mess too :/
>
> Let me read more..

Yea, I see both arguments; a field probably wouldn't be that bad. In
any case, this seemed reasonable and avoids more touchpoints in
core.c, so *shrug*.