From: Chris Mason <clm@fb.com>
To: Bastien Bastien Philbert <bastienphilbert@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Matt Fleming <matt@codeblueprint.co.uk>,
Mike Galbraith <mgalbraith@suse.de>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFC] select_idle_sibling experiments
Date: Tue, 5 Apr 2016 15:28:29 -0400 [thread overview]
Message-ID: <20160405192829.vjv7z4xzpr64kcwe@floor.thefacebook.com> (raw)
In-Reply-To: <CACJ9a8R+vi4CeRFkJH-9ymWGHuM_SrV=v6qcmWtqzpQuZHK0yQ@mail.gmail.com>
On Tue, Apr 05, 2016 at 02:43:09PM -0400, Bastien Bastien Philbert wrote:
> On Tue, Apr 5, 2016 at 2:08 PM, Chris Mason <clm@fb.com> wrote:
[ ... ]
> >
> > I tried a few variations on select_idle_sibling() that preserved the
> > underlying goal of returning idle cores before idle SMT threads. They
> > were all horrible in different ways, and none of them were fast.
> >
> > The patch below just makes select_idle_sibling pick the first idle
> > thread it can find. When I ran it through production workloads here, it
> > was faster than the patch we've been carrying around for the last few
> > years.
[ ... ]
> >
> Here is my concern, do you test this on standard scheduler workloads
> or was this just written for Facebook's internal workloads. I am going
> to test this later because frankly this may cause a regression on my
> system which has only 4 cores so a idle CPU is probably less common
> for a small amount of time. I am wondering however if Ingo has any
> complains before I test this to see if it causes a regression or a bug
> on my system. Ingo do you have any thoughts on this or would you like
> me to just test this? Bastien
Pretty much every commit to select_idle_sibling over the last few years
was somehow trying to preserve or improve the select-idle-cores-first
functionality I just ripped out. So, it's safe to assume it'll break
something ;)
-chris
next prev parent reply other threads:[~2016-04-05 19:29 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-05 18:08 [PATCH RFC] select_idle_sibling experiments Chris Mason
2016-04-05 18:43 ` Bastien Bastien Philbert
2016-04-05 19:28 ` Chris Mason [this message]
2016-04-05 20:03 ` Matt Fleming
2016-04-05 21:05 ` Bastien Philbert
2016-04-06 0:44 ` Chris Mason
2016-04-06 7:27 ` Mike Galbraith
2016-04-06 13:36 ` Chris Mason
2016-04-09 17:30 ` Chris Mason
2016-04-12 21:45 ` Matt Fleming
2016-04-13 3:40 ` Mike Galbraith
2016-04-13 15:54 ` Chris Mason
2016-04-28 12:00 ` Peter Zijlstra
2016-04-28 13:17 ` Mike Galbraith
2016-05-02 5:35 ` Mike Galbraith
2016-04-07 15:17 ` Chris Mason
2016-04-09 19:05 ` sched: tweak select_idle_sibling to look for idle threads Chris Mason
2016-04-10 10:04 ` Mike Galbraith
2016-04-10 12:35 ` Chris Mason
2016-04-10 12:46 ` Mike Galbraith
2016-04-10 19:55 ` Chris Mason
2016-04-11 4:54 ` Mike Galbraith
2016-04-12 0:30 ` Chris Mason
2016-04-12 4:44 ` Mike Galbraith
2016-04-12 13:27 ` Chris Mason
2016-04-12 18:16 ` Mike Galbraith
2016-04-12 20:07 ` Chris Mason
2016-04-13 3:18 ` Mike Galbraith
2016-04-13 13:44 ` Chris Mason
2016-04-13 14:22 ` Mike Galbraith
2016-04-13 14:36 ` Chris Mason
2016-04-13 15:05 ` Mike Galbraith
2016-04-13 15:34 ` Mike Galbraith
2016-04-30 12:47 ` Peter Zijlstra
2016-05-01 7:12 ` Mike Galbraith
2016-05-01 8:53 ` Peter Zijlstra
2016-05-01 9:20 ` Mike Galbraith
2016-05-07 1:24 ` Yuyang Du
2016-05-08 8:08 ` Mike Galbraith
2016-05-08 18:57 ` Yuyang Du
2016-05-09 3:45 ` Mike Galbraith
2016-05-08 20:22 ` Yuyang Du
2016-05-09 7:44 ` Mike Galbraith
2016-05-09 1:13 ` Yuyang Du
2016-05-09 9:39 ` Mike Galbraith
2016-05-09 23:26 ` Yuyang Du
2016-05-10 7:49 ` Mike Galbraith
2016-05-10 15:26 ` Mike Galbraith
2016-05-10 19:16 ` Yuyang Du
2016-05-11 4:17 ` Mike Galbraith
2016-05-11 1:23 ` Yuyang Du
2016-05-11 9:56 ` Mike Galbraith
2016-05-18 6:41 ` Mike Galbraith
2016-05-09 3:52 ` Mike Galbraith
2016-05-08 20:31 ` Yuyang Du
2016-05-02 8:46 ` Peter Zijlstra
2016-05-02 14:50 ` Mike Galbraith
2016-05-02 14:58 ` Peter Zijlstra
2016-05-02 15:47 ` Chris Mason
2016-05-03 14:32 ` Peter Zijlstra
2016-05-03 15:11 ` Chris Mason
2016-05-04 10:37 ` Peter Zijlstra
2016-05-04 15:31 ` Peter Zijlstra
2016-05-05 22:03 ` Matt Fleming
2016-05-06 18:54 ` Mike Galbraith
2016-05-09 8:33 ` Peter Zijlstra
2016-05-09 8:56 ` Mike Galbraith
2016-05-04 15:45 ` Peter Zijlstra
2016-05-04 17:46 ` Chris Mason
2016-05-05 9:33 ` Peter Zijlstra
2016-05-05 13:58 ` Chris Mason
2016-05-06 7:12 ` Peter Zijlstra
2016-05-06 17:27 ` Chris Mason
2016-05-06 7:25 ` Peter Zijlstra
2016-05-02 17:30 ` Mike Galbraith
2016-05-02 15:01 ` Peter Zijlstra
2016-05-02 16:04 ` Ingo Molnar
2016-05-03 11:31 ` Peter Zijlstra
2016-05-03 18:22 ` Peter Zijlstra
2016-05-02 15:10 ` Peter Zijlstra
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