From: Mel Gorman <mgorman@techsingularity.net>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Barry Song <song.bao.hua@hisilicon.com>,
Juri Lelli <juri.lelli@redhat.com>,
Peter Ziljstra <peterz@infradead.org>,
Aubrey Li <aubrey.li@linux.intel.com>,
LKML <linux-kernel@vger.kernel.org>,
Valentin Schneider <valentin.schneider@arm.com>,
Ingo Molnar <mingo@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Linux-ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 1/4] sched/fair: Remove SIS_AVG_CPU
Date: Tue, 8 Dec 2020 13:36:50 +0000 [thread overview]
Message-ID: <20201208133650.GI3371@techsingularity.net> (raw)
In-Reply-To: <CAKfTPtBgo5vCrN87fqKjyaowONLMWeUusLmvE4bmGmDq10+Yrw@mail.gmail.com>
On Tue, Dec 08, 2020 at 02:24:32PM +0100, Vincent Guittot wrote:
> > > Nitpick:
> > >
> > > Since now avg_cost and avg_idle are only used w/ SIS_PROP, they could go
> > > completely into the SIS_PROP if condition.
> > >
> >
> > Yeah, I can do that. In the initial prototype, that happened in a
> > separate patch that split out SIS_PROP into a helper function and I
> > never merged it back. It's a trivial change.
>
> while doing this, should you also put the update of
> this_sd->avg_scan_cost under the SIS_PROP feature ?
>
It's outside the scope of the series but why not. This?
--8<--
sched/fair: Move avg_scan_cost calculations under SIS_PROP
As noted by Vincent Guittot, avg_scan_costs are calculated for SIS_PROP
even if SIS_PROP is disabled. Move the time calculations under a SIS_PROP
check and while we are at it, exclude the cost of initialising the CPU
mask from the average scan cost.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 19ca0265f8aa..0fee53b1aae4 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6176,10 +6176,10 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t
nr = 4;
}
- time = cpu_clock(this);
-
cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
+ if (sched_feat(SIS_PROP))
+ time = cpu_clock(this);
for_each_cpu_wrap(cpu, cpus, target) {
if (!--nr)
return -1;
@@ -6187,8 +6187,10 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t
break;
}
- time = cpu_clock(this) - time;
- update_avg(&this_sd->avg_scan_cost, time);
+ if (sched_feat(SIS_PROP)) {
+ time = cpu_clock(this) - time;
+ update_avg(&this_sd->avg_scan_cost, time);
+ }
return cpu;
}
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-12-08 13:38 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-07 9:15 [RFC PATCH 0/4] Reduce worst-case scanning of runqueues in select_idle_sibling Mel Gorman
2020-12-07 9:15 ` [PATCH 1/4] sched/fair: Remove SIS_AVG_CPU Mel Gorman
2020-12-07 15:05 ` Vincent Guittot
2020-12-08 10:07 ` Dietmar Eggemann
2020-12-08 10:59 ` Mel Gorman
2020-12-08 13:24 ` Vincent Guittot
2020-12-08 13:36 ` Mel Gorman [this message]
2020-12-08 13:43 ` Vincent Guittot
2020-12-08 13:53 ` Mel Gorman
2020-12-08 14:47 ` Vincent Guittot
2020-12-08 15:12 ` Mel Gorman
2020-12-08 15:19 ` Vincent Guittot
2020-12-07 9:15 ` [PATCH 2/4] sched/fair: Do not replace recent_used_cpu with the new target Mel Gorman
2020-12-08 9:57 ` Dietmar Eggemann
2020-12-08 11:02 ` Mel Gorman
2020-12-07 9:15 ` [PATCH 3/4] sched/fair: Return an idle cpu if one is found after a failed search for an idle core Mel Gorman
2020-12-07 15:06 ` Vincent Guittot
2020-12-07 9:15 ` [PATCH 4/4] sched/fair: Avoid revisiting CPUs multiple times during select_idle_sibling Mel Gorman
2020-12-07 15:04 ` [RFC PATCH 0/4] Reduce worst-case scanning of runqueues in select_idle_sibling Vincent Guittot
2020-12-07 15:42 ` Mel Gorman
2020-12-08 2:06 ` Li, Aubrey
-- strict thread matches above, loose matches on Subject: below --
2020-12-08 15:34 [PATCH 0/4] Reduce " Mel Gorman
2020-12-08 15:34 ` [PATCH 1/4] sched/fair: Remove SIS_AVG_CPU Mel Gorman
2020-12-08 16:13 ` 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=20201208133650.GI3371@techsingularity.net \
--to=mgorman@techsingularity.net \
--cc=aubrey.li@linux.intel.com \
--cc=dietmar.eggemann@arm.com \
--cc=juri.lelli@redhat.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=song.bao.hua@hisilicon.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;
as well as URLs for NNTP newsgroup(s).