From: tip-bot for Peter Zijlstra <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: luto@kernel.org, efault@gmx.de, mingo@kernel.org,
chris@chris-wilson.co.uk, linux-kernel@vger.kernel.org,
hpa@zytor.com, torvalds@linux-foundation.org,
peterz@infradead.org, tglx@linutronix.de
Subject: [tip:sched/urgent] sched/fair: Fix wake_affine_llc() balancing rules
Date: Thu, 7 Sep 2017 01:16:24 -0700 [thread overview]
Message-ID: <tip-a731ebe6f17bff9e7ca12ef227f9da4d5bdf8425@git.kernel.org> (raw)
In-Reply-To: <20170906105131.gqjmaextmn3u6tj2@hirez.programming.kicks-ass.net>
Commit-ID: a731ebe6f17bff9e7ca12ef227f9da4d5bdf8425
Gitweb: http://git.kernel.org/tip/a731ebe6f17bff9e7ca12ef227f9da4d5bdf8425
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Wed, 6 Sep 2017 12:51:31 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 7 Sep 2017 09:29:31 +0200
sched/fair: Fix wake_affine_llc() balancing rules
Chris Wilson reported that the SMT balance rules got the +1 on the
wrong side, resulting in a bias towards the current LLC; which the
load-balancer would then try and undo.
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: 90001d67be2f ("sched/fair: Fix wake_affine() for !NUMA_BALANCING")
Link: http://lkml.kernel.org/r/20170906105131.gqjmaextmn3u6tj2@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/fair.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8d58687..9dd2ce1 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5435,7 +5435,7 @@ wake_affine_llc(struct sched_domain *sd, struct task_struct *p,
return false;
/* if this cache has capacity, come here */
- if (this_stats.has_capacity && this_stats.nr_running < prev_stats.nr_running+1)
+ if (this_stats.has_capacity && this_stats.nr_running+1 < prev_stats.nr_running)
return true;
/*
prev parent reply other threads:[~2017-09-07 8:21 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-06 5:13 Abysmal scheduler performance in Linus' tree? Andy Lutomirski
2017-09-06 8:25 ` Peter Zijlstra
2017-09-06 8:59 ` Andy Lutomirski
2017-09-06 9:03 ` Peter Zijlstra
2017-09-06 16:14 ` Peter Zijlstra
2017-09-07 6:15 ` Mike Galbraith
2017-09-07 7:31 ` Ingo Molnar
2017-09-07 9:13 ` [PATCH] sched/cpuset/pm: Fix cpuset vs suspend-resume Peter Zijlstra
2017-09-07 9:26 ` Peter Zijlstra
2017-09-07 10:54 ` Rafael J. Wysocki
2017-09-07 20:38 ` Tejun Heo
2017-09-07 10:33 ` [tip:sched/urgent] sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs tip-bot for Peter Zijlstra
2017-09-06 9:15 ` Abysmal scheduler performance in Linus' tree? Chris Wilson
2017-09-06 9:24 ` Peter Zijlstra
[not found] ` <150469312649.28581.17626550155735691534@mail.alporthouse.com>
2017-09-06 10:44 ` Peter Zijlstra
2017-09-06 10:51 ` Peter Zijlstra
2017-09-07 8:16 ` tip-bot for Peter Zijlstra [this message]
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=tip-a731ebe6f17bff9e7ca12ef227f9da4d5bdf8425@git.kernel.org \
--to=tipbot@zytor.com \
--cc=chris@chris-wilson.co.uk \
--cc=efault@gmx.de \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.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).