From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Russell King - ARM Linux <linux@arm.linux.org.uk>,
LAK <linux-arm-kernel@lists.infradead.org>,
Preeti U Murthy <preeti@linux.vnet.ibm.com>,
Morten Rasmussen <Morten.Rasmussen@arm.com>,
Mike Galbraith <efault@gmx.de>,
Nicolas Pitre <nicolas.pitre@linaro.org>,
"linaro-kernel@lists.linaro.org" <linaro-kernel@lists.linaro.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>
Subject: Re: [PATCH v3 08/12] sched: move cfs task on a CPU with higher capacity
Date: Fri, 11 Jul 2014 16:51:38 +0200 [thread overview]
Message-ID: <20140711145138.GC3935@laptop> (raw)
In-Reply-To: <CAKfTPtD=TiURcppZ+oVUmhMf6Ofxbp4BPA0SCFViu0SDb05oRw@mail.gmail.com>
On Thu, Jul 10, 2014 at 04:03:51PM +0200, Vincent Guittot wrote:
> On 10 July 2014 13:18, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Mon, Jun 30, 2014 at 06:05:39PM +0200, Vincent Guittot wrote:
> >> + /*
> >> + * If the CPUs share their cache and the src_cpu's capacity is
> >> + * reduced because of other sched_class or IRQs, we trig an
> >> + * active balance to move the task
> >> + */
> >> + if ((sd->flags & SD_SHARE_PKG_RESOURCES)
> >> + && ((capacity_orig_of(src_cpu) * 100) > (capacity_of(src_cpu) *
> >> + sd->imbalance_pct)))
> >> return 1;
> >
> > Why is this tied to shared caches?
>
> It's just to limit the change of the policy to a level that can have
> benefit without performance regression. I'm not sure that we can do
> that at any level without risk
Similar to the other change; so both details _should_ have been in the
changelogs etc..
In any case, its feels rather arbitrary to me. What about machines where
there's no cache sharing at all (the traditional SMP systems). This
thing you're trying to do still seems to make sense there.
next prev parent reply other threads:[~2014-07-11 14:52 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-30 16:05 [PATCH v3 00/12] sched: consolidation of cpu_power Vincent Guittot
2014-06-30 16:05 ` [PATCH v3 01/12] sched: fix imbalance flag reset Vincent Guittot
2014-07-08 3:13 ` Preeti U Murthy
2014-07-08 10:12 ` Vincent Guittot
2014-07-09 3:54 ` Preeti U Murthy
2014-07-09 8:27 ` Vincent Guittot
2014-07-09 10:43 ` Peter Zijlstra
2014-07-09 11:41 ` Preeti U Murthy
2014-07-09 14:44 ` Peter Zijlstra
2014-07-10 9:14 ` Vincent Guittot
2014-07-10 9:30 ` [PATCH v4 ] " Vincent Guittot
2014-07-10 10:57 ` Preeti U Murthy
2014-07-10 11:04 ` [PATCH v3 01/12] " Preeti U Murthy
2014-07-09 3:05 ` Rik van Riel
2014-07-09 3:36 ` Rik van Riel
2014-07-09 10:14 ` Peter Zijlstra
2014-07-09 10:30 ` Vincent Guittot
2014-06-30 16:05 ` [PATCH v3 02/12] sched: remove a wake_affine condition Vincent Guittot
2014-07-09 3:06 ` Rik van Riel
2014-06-30 16:05 ` [PATCH v3 03/12] sched: fix avg_load computation Vincent Guittot
2014-07-09 3:10 ` Rik van Riel
2014-06-30 16:05 ` [PATCH v3 04/12] sched: Allow all archs to set the power_orig Vincent Guittot
2014-07-09 3:11 ` Rik van Riel
2014-07-09 10:57 ` Peter Zijlstra
2014-07-10 13:42 ` Vincent Guittot
2014-06-30 16:05 ` [PATCH v3 05/12] ARM: topology: use new cpu_power interface Vincent Guittot
2014-07-09 3:11 ` Rik van Riel
2014-07-09 7:49 ` Amit Kucheria
2014-07-09 10:09 ` Vincent Guittot
2014-06-30 16:05 ` [PATCH v3 06/12] sched: add per rq cpu_power_orig Vincent Guittot
2014-07-09 3:11 ` Rik van Riel
2014-07-09 7:50 ` Amit Kucheria
2014-06-30 16:05 ` [PATCH v3 07/12] sched: test the cpu's capacity in wake affine Vincent Guittot
2014-07-09 3:12 ` Rik van Riel
2014-07-10 11:06 ` Peter Zijlstra
2014-07-10 13:58 ` Vincent Guittot
2014-06-30 16:05 ` [PATCH v3 08/12] sched: move cfs task on a CPU with higher capacity Vincent Guittot
2014-07-10 11:18 ` Peter Zijlstra
2014-07-10 14:03 ` Vincent Guittot
2014-07-11 14:51 ` Peter Zijlstra [this message]
2014-07-11 15:17 ` Vincent Guittot
2014-07-14 13:51 ` Peter Zijlstra
2014-07-15 9:21 ` Vincent Guittot
2014-07-10 11:24 ` Peter Zijlstra
2014-07-10 13:59 ` Vincent Guittot
2014-07-10 11:31 ` Peter Zijlstra
2014-06-30 16:05 ` [PATCH v3 09/12] Revert "sched: Put rq's sched_avg under CONFIG_FAIR_GROUP_SCHED" Vincent Guittot
2014-07-10 13:16 ` Peter Zijlstra
2014-07-11 7:51 ` Vincent Guittot
2014-07-11 15:13 ` Peter Zijlstra
2014-07-11 17:39 ` Vincent Guittot
2014-07-11 20:12 ` Peter Zijlstra
2014-07-14 12:55 ` Morten Rasmussen
2014-07-14 13:20 ` Peter Zijlstra
2014-07-14 14:04 ` Morten Rasmussen
2014-07-14 16:22 ` Peter Zijlstra
2014-07-15 9:20 ` Vincent Guittot
2014-07-14 17:54 ` Dietmar Eggemann
2014-07-18 1:27 ` Yuyang Du
2014-07-11 16:13 ` Morten Rasmussen
2014-07-15 9:27 ` Vincent Guittot
2014-07-15 9:32 ` Morten Rasmussen
2014-07-15 9:53 ` Vincent Guittot
2014-06-30 16:05 ` [PATCH v3 10/12] sched: get CPU's utilization statistic Vincent Guittot
2014-06-30 16:05 ` [PATCH v3 11/12] sched: replace capacity_factor by utilization Vincent Guittot
2014-06-30 16:05 ` [PATCH v3 12/12] sched: add SD_PREFER_SIBLING for SMT level Vincent Guittot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20140711145138.GC3935@laptop \
--to=peterz@infradead.org \
--cc=Morten.Rasmussen@arm.com \
--cc=daniel.lezcano@linaro.org \
--cc=dietmar.eggemann@arm.com \
--cc=efault@gmx.de \
--cc=linaro-kernel@lists.linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=mingo@kernel.org \
--cc=nicolas.pitre@linaro.org \
--cc=preeti@linux.vnet.ibm.com \
--cc=vincent.guittot@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox