From: Juri Lelli <Juri.Lelli@arm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Steve Muckle <steve.muckle@linaro.org>,
Michael Turquette <mturquette@baylibre.com>,
rjw@rjwysocki.net, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org, morten.rasmussen@arm.com,
dietmar.eggemann@arm.com, vincent.guittot@linaro.org,
Michael Turquette <mturquette+renesas@baylibre.com>,
Patrick Bellasi <patrick.bellasi@arm.com>
Subject: Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable
Date: Wed, 16 Mar 2016 10:02:57 +0000 [thread overview]
Message-ID: <20160316100257.GC18212@e106622-lin> (raw)
In-Reply-To: <20160316080503.GS6344@twins.programming.kicks-ass.net>
Hi,
On 16/03/16 09:05, Peter Zijlstra wrote:
> On Tue, Mar 15, 2016 at 08:36:57PM -0700, Steve Muckle wrote:
> > > Then again, maybe this knob will be part of the mythical
> > > power-vs-performance slider?
> >
> > Patrick Bellasi's schedtune series [0] (which I think is the referenced
> > mythical slider) aims to provide a more sophisticated interface for
> > tuning scheduler-driven frequency selection. In addition to a global
> > boost value it includes a cgroup controller as well for per-task tuning.
> >
> > I would definitely expect the margin/boost value to be modified at
> > runtime, for example if the battery is running low, or the user wants
> > 100% performance for a while, or the userspace framework wants to
> > temporarily tailor the performance level for a particular set of tasks, etc.
>
> OK, so how about we start with it as a debug knob, and once we have
> experience and feel like it is indeed a useful runtime knob, we upgrade
> it to ABI.
>
I tend to agree here. To me the margin is something that we need to make
this thing work and to get acceptable performance out of the box. So we
can play with it while debugging, but I consider the schedtune slider as
the way to tune the system at runtime.
Best,
- Juri
next prev parent reply other threads:[~2016-03-16 10:01 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-14 5:22 [PATCH 0/8] schedutil enhancements Michael Turquette
2016-03-14 5:22 ` [PATCH 1/8] sched/cpufreq: remove cpufreq_trigger_update() Michael Turquette
2016-03-15 21:14 ` Peter Zijlstra
[not found] ` <20160315214545.30639.98727@quark.deferred.io>
2016-03-15 21:49 ` Peter Zijlstra
2016-03-16 8:00 ` Peter Zijlstra
2016-03-14 5:22 ` [PATCH 2/8] sched/fair: add margin to utilization update Michael Turquette
2016-03-15 21:16 ` Peter Zijlstra
[not found] ` <20160315212848.30639.38747@quark.deferred.io>
2016-03-15 21:43 ` Peter Zijlstra
2016-03-16 2:52 ` Steve Muckle
2016-03-16 22:12 ` Michael Turquette
2016-03-14 5:22 ` [PATCH 3/8] sched/cpufreq: new cfs capacity margin helpers Michael Turquette
2016-03-15 21:17 ` Peter Zijlstra
2016-03-14 5:22 ` [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable Michael Turquette
2016-03-15 21:20 ` Peter Zijlstra
[not found] ` <20160315214043.30639.75507@quark.deferred.io>
2016-03-15 21:48 ` Peter Zijlstra
[not found] ` <20160315223701.30639.43127@quark.deferred.io>
2016-03-16 3:36 ` Steve Muckle
2016-03-16 8:05 ` Peter Zijlstra
2016-03-16 10:02 ` Juri Lelli [this message]
2016-03-16 17:55 ` Steve Muckle
2016-03-16 22:05 ` Michael Turquette
2016-03-17 9:40 ` Juri Lelli
2016-03-17 13:55 ` Steve Muckle
2016-03-17 15:53 ` Patrick Bellasi
2016-03-17 17:54 ` Juri Lelli
2016-03-17 18:56 ` Michael Turquette
2016-03-17 22:34 ` Rafael J. Wysocki
2016-03-16 12:45 ` Rafael J. Wysocki
2016-03-16 22:03 ` Michael Turquette
2016-03-14 5:22 ` [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util Michael Turquette
2016-03-15 21:25 ` Peter Zijlstra
[not found] ` <20160315220609.30639.67271@quark.deferred.io>
2016-03-16 3:55 ` Steve Muckle
2016-03-16 7:41 ` Peter Zijlstra
2016-03-16 8:29 ` Vincent Guittot
2016-03-16 8:53 ` Peter Zijlstra
2016-03-16 9:16 ` Vincent Guittot
2016-03-16 12:39 ` Rafael J. Wysocki
2016-03-16 13:10 ` Peter Zijlstra
2016-03-16 13:23 ` Rafael J. Wysocki
2016-03-16 13:43 ` Peter Zijlstra
2016-03-14 5:22 ` [PATCH 6/8] cpufreq/schedutil: sum per-sched class utilization Michael Turquette
2016-03-15 21:29 ` Peter Zijlstra
[not found] ` <20160315220951.30639.12872@quark.deferred.io>
2016-03-16 7:38 ` Peter Zijlstra
2016-03-16 18:20 ` Steve Muckle
2016-03-16 18:36 ` Peter Zijlstra
2016-03-16 19:12 ` Steve Muckle
2016-03-14 5:22 ` [PATCH 7/8] cpufreq: Frequency invariant scheduler load-tracking support Michael Turquette
2016-03-15 19:13 ` Dietmar Eggemann
2016-03-15 20:19 ` Michael Turquette
2016-03-15 21:32 ` Peter Zijlstra
2016-03-16 18:33 ` Dietmar Eggemann
2016-03-15 21:34 ` Peter Zijlstra
2016-03-14 5:22 ` [PATCH 8/8] sched: prefer cpufreq_scale_freq_capacity Michael Turquette
2016-03-15 19:13 ` Dietmar Eggemann
2016-03-15 20:46 ` Michael Turquette
2016-03-16 19:44 ` Dietmar Eggemann
2016-03-16 20:07 ` Peter Zijlstra
2016-03-16 21:32 ` Rafael J. Wysocki
2016-03-15 21:37 ` Peter Zijlstra
[not found] ` <20160315222721.30639.28332@quark.deferred.io>
2016-03-16 7:47 ` Peter Zijlstra
2016-03-16 12:41 ` Peter Zijlstra
2016-03-16 0:08 ` [PATCH 0/8] schedutil enhancements Rafael J. Wysocki
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