From: Peter Zijlstra <peterz@infradead.org>
To: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>, Jiri Olsa <jolsa@redhat.com>,
James Hartsock <hartsjc@redhat.com>,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Kirill Tkhai <ktkhai@parallels.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC] sched: unused cpu in affine workload
Date: Mon, 4 Apr 2016 23:34:50 +0200 [thread overview]
Message-ID: <20160404213450.GE3448@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1459799116.6219.24.camel@redhat.com>
On Mon, Apr 04, 2016 at 03:45:16PM -0400, Rik van Riel wrote:
> An optimal solution is NP hard.
>
> Heuristics that "move tasks with pressure" may be
> much more doable, and lead to perfectly satisfactory
> results, especially if most migrations happen within
> a socket (and the same shared L3 cache).
Right; trick will be finding something that mostly works without making
the regular balance paths increase in complexity.
As per the argument in kernel/sched/fair.c:5694 the current
load-balancing averages out to O(n), and I would very much like to keep
it that way.
next prev parent reply other threads:[~2016-04-04 21:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-04 8:23 Jiri Olsa
2016-04-04 8:44 ` Peter Zijlstra
2016-04-04 8:59 ` Ingo Molnar
2016-04-04 9:19 ` Ingo Molnar
2016-04-04 9:38 ` Ingo Molnar
2016-04-04 13:23 ` Peter Zijlstra
2016-04-04 19:45 ` Rik van Riel
2016-04-04 21:34 ` Peter Zijlstra [this message]
2016-04-05 8:56 ` Jiri Olsa
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=20160404213450.GE3448@twins.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=hartsjc@redhat.com \
--cc=jolsa@redhat.com \
--cc=ktkhai@parallels.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=riel@redhat.com \
--cc=vatsa@linux.vnet.ibm.com \
/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
Powered by JetHome