From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc: Linux PM <linux-pm@vger.kernel.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Viresh Kumar <viresh.kumar@linaro.org>,
Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: cpufreq - powernv driver
Date: Mon, 26 Sep 2022 15:40:06 +0200 [thread overview]
Message-ID: <CAJZ5v0hpqdX78LWqyMLHWLmy47NiGpuavg-V9D6wrGPekPjMTA@mail.gmail.com> (raw)
In-Reply-To: <12f6625f-bd93-80c2-3a8c-19c63f49ea10@linutronix.de>
On Mon, Sep 26, 2022 at 3:20 PM Anna-Maria Behnsen
<anna-maria@linutronix.de> wrote:
>
> ping?
Sorry, this fell off my radar.
> On Mon, 27 Jun 2022, Anna-Maria Behnsen wrote:
>
> > Hi,
> >
> > during my work on a timer hierarchy I stumbled over powernv cpufreq driver
> > which is using a timer which is deferrable and pinned. This is the only
> > timer in kernel which uses this combination and I would like to get rid of
> > it.
> >
> > Only removing the pinned or deferrable flag could not be the proper
> > solution, right?
> >
> > I'm not familiar with cpufreq. I was wondering if it's possible to rework
> > the powernv cpufreq driver to use cpufreq infrastructure instead handling
> > it's own timer for ramping down? I would be happy if someone could help me
> > with some pointers how this could be solved.
cpufreq drivers need not use timers at all in general.
What they need to do is to register a callback via
cpufreq_add_update_util_hook(), like intel_pstate or the schedutil
governor.
I'll look at the powernv driver later this week.
> > Thanks,
> >
> > Anna-Maria
> >
prev parent reply other threads:[~2022-09-26 15:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-27 13:24 cpufreq - powernv driver Anna-Maria Behnsen
2022-09-26 13:20 ` Anna-Maria Behnsen
2022-09-26 13:40 ` Rafael J. Wysocki [this message]
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