From: Rik van Riel <riel@surriel.com>
To: Mel Gorman <mgorman@techsingularity.net>,
Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
pauld@redhat.com, valentin.schneider@arm.com,
srikar@linux.vnet.ibm.com, quentin.perret@arm.com,
dietmar.eggemann@arm.com, Morten.Rasmussen@arm.com,
hdanton@sina.com, parth@linux.ibm.com,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] sched, fair: Allow a small degree of load imbalance between SD_NUMA domains
Date: Wed, 18 Dec 2019 21:58:01 -0500 [thread overview]
Message-ID: <37ec5587dbb4035b883e5a69b56da4cc67f0e5ff.camel@surriel.com> (raw)
In-Reply-To: <20191218154402.GF3178@techsingularity.net>
[-- Attachment #1: Type: text/plain, Size: 719 bytes --]
On Wed, 2019-12-18 at 15:44 +0000, Mel Gorman wrote:
> + /*
> + * Ignore imbalance unless busiest sd is close
> to 50%
> + * utilisation. At that point balancing for
> memory
> + * bandwidth and potentially avoiding
> unnecessary use
> + * of HT siblings is as relevant as memory
> locality.
> + */
> + imbalance_max = (busiest->group_weight >> 1) -
> imbalance_adj;
> + if (env->imbalance <= imbalance_adj &&
> + busiest->sum_nr_running < imbalance_max) {
> + env->imbalance = 0;
> + }
> + }
> return;
> }
I can see how the 50% point is often great for HT,
but I wonder if that is also the case for SMT4 and
SMT8 systems...
--
All Rights Reversed.
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
next prev parent reply other threads:[~2019-12-19 2:58 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-18 15:44 Mel Gorman
2019-12-18 18:50 ` Valentin Schneider
2019-12-18 22:50 ` Mel Gorman
2019-12-19 11:56 ` Valentin Schneider
2019-12-19 10:02 ` Peter Zijlstra
2019-12-19 11:46 ` Valentin Schneider
2019-12-19 14:23 ` Valentin Schneider
2019-12-19 15:23 ` Mel Gorman
2019-12-18 18:54 ` Valentin Schneider
2019-12-19 2:58 ` Rik van Riel [this message]
2019-12-19 8:41 ` Mel Gorman
2019-12-19 10:04 ` Peter Zijlstra
2019-12-19 14:45 ` Vincent Guittot
2019-12-19 15:16 ` Valentin Schneider
2019-12-19 15:18 ` Mel Gorman
2019-12-19 15:41 ` Vincent Guittot
2019-12-19 15:58 ` Mel Gorman
2019-12-20 13:00 ` Srikar Dronamraju
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=37ec5587dbb4035b883e5a69b56da4cc67f0e5ff.camel@surriel.com \
--to=riel@surriel.com \
--cc=Morten.Rasmussen@arm.com \
--cc=dietmar.eggemann@arm.com \
--cc=hdanton@sina.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@techsingularity.net \
--cc=mingo@kernel.org \
--cc=parth@linux.ibm.com \
--cc=pauld@redhat.com \
--cc=peterz@infradead.org \
--cc=quentin.perret@arm.com \
--cc=srikar@linux.vnet.ibm.com \
--cc=valentin.schneider@arm.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
Powered by JetHome