From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>,
Julia Lawall <julia.lawall@inria.fr>,
Mel Gorman <mgorman@suse.de>, Ingo Molnar <mingo@redhat.com>,
kernel-janitors@vger.kernel.org,
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>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
linux-kernel@vger.kernel.org,
Valentin Schneider <valentin.schneider@arm.com>,
Gilles Muller <Gilles.Muller@inria.fr>,
srinivas.pandruvada@linux.intel.com,
Linux PM <linux-pm@vger.kernel.org>,
Len Brown <len.brown@intel.com>
Subject: Re: default cpufreq gov, was: [PATCH] sched/fair: check for idle core
Date: Thu, 22 Oct 2020 14:19:29 +0200 [thread overview]
Message-ID: <1790766.jaFeG3T87Z@kreacher> (raw)
In-Reply-To: <20201022120213.GG2611@hirez.programming.kicks-ass.net>
[CC linux-pm and Len]
On Thursday, October 22, 2020 2:02:13 PM CEST Peter Zijlstra wrote:
> On Thu, Oct 22, 2020 at 01:45:25PM +0200, Rafael J. Wysocki wrote:
> > On Thursday, October 22, 2020 12:47:03 PM CEST Viresh Kumar wrote:
> > > On 22-10-20, 09:11, Peter Zijlstra wrote:
> > > > Well, but we need to do something to force people onto schedutil,
> > > > otherwise we'll get more crap like this thread.
> > > >
> > > > Can we take the choice away? Only let Kconfig select which governors are
> > > > available and then set the default ourselves? I mean, the end goal being
> > > > to not have selectable governors at all, this seems like a good step
> > > > anyway.
> > >
> > > Just to clarify and complete the point a bit here, the users can still
> > > pass the default governor from cmdline using
> > > cpufreq.default_governor=, which will take precedence over the one the
> > > below code is playing with. And later once the kernel is up, they can
> > > still choose a different governor from userspace.
> >
> > Right.
> >
> > Also some people simply set "performance" as the default governor and then
> > don't touch cpufreq otherwise (the idea is to get everything to the max
> > freq right away and stay in that mode forever). This still needs to be
> > possible IMO.
>
> Performance/powersave make sense to keep.
>
> However I do want to retire ondemand, conservative and also very much
> intel_pstate/active mode.
I agree in general, but IMO it would not be prudent to do that without making
schedutil provide the same level of performance in all of the relevant use
cases.
> I also have very little sympathy for userspace.
That I completely agree with.
> We should start by making it hard to use them and eventually just delete
> them outright.
Right, but see above: IMO step 0 should be to ensure that schedutil is a viable
replacement for all users.
next parent reply other threads:[~2020-10-22 12:19 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1603211879-1064-1-git-send-email-Julia.Lawall@inria.fr>
[not found] ` <34115486.YmRjPRKJaA@kreacher>
[not found] ` <20201022120213.GG2611@hirez.programming.kicks-ass.net>
2020-10-22 12:19 ` Rafael J. Wysocki [this message]
2020-10-22 12:29 ` default cpufreq gov, was: [PATCH] sched/fair: check for idle core Peter Zijlstra
2020-10-22 14:52 ` Mel Gorman
2020-10-22 14:58 ` Colin Ian King
2020-10-22 15:12 ` Phil Auld
2020-10-22 16:35 ` Mel Gorman
2020-10-22 17:59 ` Rafael J. Wysocki
2020-10-22 20:32 ` Mel Gorman
2020-10-22 20:39 ` Phil Auld
2020-10-22 15:25 ` Peter Zijlstra
2020-10-22 15:55 ` Rafael J. Wysocki
2020-10-22 16:29 ` Mel Gorman
2020-10-22 20:10 ` Giovanni Gherdovich
2020-10-22 20:16 ` Giovanni Gherdovich
2020-10-23 7:03 ` Peter Zijlstra
2020-10-23 17:46 ` Tom Lendacky
2020-10-26 19:52 ` Fontenot, Nathan
2020-10-22 15:45 ` A L
2020-10-22 15:55 ` Vincent Guittot
2020-10-23 5:11 ` Viresh Kumar
2020-10-22 16:23 ` [PATCH] cpufreq: Avoid configuring old governors as default with intel_pstate Rafael J. Wysocki
2020-10-23 6:17 ` Viresh Kumar
2020-10-23 11:59 ` Rafael J. Wysocki
2020-10-23 15:15 ` [PATCH v2] " Rafael J. Wysocki
2020-10-27 3:01 ` Viresh Kumar
[not found] ` <20201023061246.irzbrl62baoawmqv@vireshk-i7>
2020-10-23 15:06 ` [PATCH] sched/fair: check for idle core Rafael J. Wysocki
2020-10-27 3:01 ` Viresh Kumar
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