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From:   Vincent Guittot <vincent.guittot@linaro.org>
Date:   Mon, 23 May 2022 17:36:29 +0200
Message-ID: <CAKfTPtB9gd5M6vvX+h3aZdOBVkWw0d+U5G5kUUtwsWuH_vanZA@mail.gmail.com>
Subject: Re: [External] Re: [RFC PATCH] sched: Enable root level cgroup
 bandwidth control
To:     "Feiran Zheng ." <fam.zheng@bytedance.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        linux-kernel@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        zhouchengming@bytedance.com, fam@euphon.net,
        Mel Gorman <mgorman@suse.de>, Ingo Molnar <mingo@redhat.com>,
        songmuchun@bytedance.com, Juri Lelli <juri.lelli@redhat.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Cristian Marussi <cristian.marussi@arm.com>
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On Wed, 18 May 2022 at 17:55, Feiran Zheng . <fam.zheng@bytedance.com> wrote:
>
> On Wed, May 18, 2022 at 3:31 PM Vincent Guittot
> <vincent.guittot@linaro.org> wrote:
> > there is a DTPM powercap provider in the latest kernel and a scmi
> > power capp provider is under review
>
>
> Thanks, so DTPM can be a good solution for ARM. We could also deal
> with AMD with acpi-cpufreq if powercap is not supported yet.
>
> That aside, I think cpu cgroup has a familiar and simple sysfs
> interface, and is more importantly hardware agnostic so it would be
> really nice to have.

cgroup is about allocating runtime to a group but you want to force a
system idle for power consideration so it looks like abusing the
interface

>
> Alternatively, I assume we can look into a device-independent idle
> injection mechanism?

Yes, idle injection is  device-independent and fit better with your needs

thermal framework already support cpu idle cooling device but I'm not
sure your case is only related to thermal so you might want a more
generic interface like powercap--> dtpm --> idle injection

>
> Fam