linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ingo Molnar <mingo@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: [GIT PULL] scheduler fix
Date: Fri, 13 May 2016 20:54:55 +0200	[thread overview]
Message-ID: <20160513185455.GA18742@gmail.com> (raw)

Linus,

Please pull the latest sched-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-urgent-for-linus

   # HEAD: 53d3bc773eaa7ab1cf63585e76af7ee869d5e709 Revert "sched/fair: Fix fairness issue on migration"

This is a revert to fix an interactivity problem. The proper fixes for the 
problems that the reverted commit exposed are now in sched/core (consisting of 3 
patches), but were too risky for v4.6 and will arrive in the v4.7 merge window.

 Thanks,

	Ingo

------------------>
Ingo Molnar (1):
      Revert "sched/fair: Fix fairness issue on migration"


 kernel/sched/fair.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 40748dc8ea3e..e7dd0ec169be 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3188,25 +3188,17 @@ static inline void check_schedstat_required(void)
 static void
 enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 {
-	bool renorm = !(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING);
-	bool curr = cfs_rq->curr == se;
-
 	/*
-	 * If we're the current task, we must renormalise before calling
-	 * update_curr().
+	 * Update the normalized vruntime before updating min_vruntime
+	 * through calling update_curr().
 	 */
-	if (renorm && curr)
+	if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING))
 		se->vruntime += cfs_rq->min_vruntime;
 
-	update_curr(cfs_rq);
-
 	/*
-	 * Otherwise, renormalise after, such that we're placed at the current
-	 * moment in time, instead of some random moment in the past.
+	 * Update run-time statistics of the 'current'.
 	 */
-	if (renorm && !curr)
-		se->vruntime += cfs_rq->min_vruntime;
-
+	update_curr(cfs_rq);
 	enqueue_entity_load_avg(cfs_rq, se);
 	account_entity_enqueue(cfs_rq, se);
 	update_cfs_shares(cfs_rq);
@@ -3222,7 +3214,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 		update_stats_enqueue(cfs_rq, se);
 		check_spread(cfs_rq, se);
 	}
-	if (!curr)
+	if (se != cfs_rq->curr)
 		__enqueue_entity(cfs_rq, se);
 	se->on_rq = 1;
 

             reply	other threads:[~2016-05-13 18:55 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-13 18:54 Ingo Molnar [this message]
  -- strict thread matches above, loose matches on Subject: below --
2023-10-01  8:43 [GIT PULL] scheduler fix Ingo Molnar
2023-10-01 17:08 ` pr-tracker-bot
2023-09-22 10:26 Ingo Molnar
2023-09-22 20:19 ` pr-tracker-bot
2021-06-24  7:06 Ingo Molnar
2021-06-24 16:34 ` pr-tracker-bot
2020-12-27  9:16 Ingo Molnar
2020-12-27 17:27 ` pr-tracker-bot
2020-03-02  7:51 Ingo Molnar
2020-03-03 23:35 ` pr-tracker-bot
2019-12-17 11:54 Ingo Molnar
2019-12-17 19:20 ` pr-tracker-bot
2019-07-14 10:19 Ingo Molnar
2019-07-14 18:45 ` pr-tracker-bot
2019-05-05 11:02 Ingo Molnar
2019-05-05 22:10 ` pr-tracker-bot
2019-04-27 14:39 Ingo Molnar
2019-04-27 18:45 ` pr-tracker-bot
2019-04-12 13:08 Ingo Molnar
2019-04-13  4:05 ` pr-tracker-bot
2018-12-31 14:58 Ingo Molnar
2018-12-31 18:05 ` pr-tracker-bot
2018-11-17 10:57 Ingo Molnar
2018-11-18 20:05 ` pr-tracker-bot
2018-10-11  9:12 Ingo Molnar
2018-10-11 12:32 ` Greg Kroah-Hartman
2018-10-11  9:02 Ingo Molnar
2018-01-17 15:34 Ingo Molnar
2017-10-27 19:16 Ingo Molnar
2016-12-07 18:48 Ingo Molnar
2016-10-28  8:35 Ingo Molnar
2016-10-19 15:52 Ingo Molnar
2016-10-18 11:17 Ingo Molnar
2016-09-13 18:17 Ingo Molnar
2016-07-14 18:56 Ingo Molnar
2016-05-06 11:31 Ingo Molnar
2015-07-18  2:56 Ingo Molnar
2015-03-28 13:45 Ingo Molnar
2014-01-15 18:19 Ingo Molnar
2013-09-28 18:08 Ingo Molnar
2013-09-12 12:58 Ingo Molnar
2012-05-17  8:46 Ingo Molnar
2012-03-02 10:57 Ingo Molnar
2012-02-27 10:29 Ingo Molnar
2011-04-07 17:38 Ingo Molnar
2011-03-18 13:52 Ingo Molnar
2011-03-10  8:01 Ingo Molnar
2011-01-24 13:07 Ingo Molnar
2010-04-08 15:38 Ingo Molnar
2010-04-08 15:42 ` Linus Torvalds
2010-04-08 16:03   ` Andreas Schwab
2010-04-08 18:26     ` Ingo Molnar
2010-04-08 18:36       ` Linus Torvalds
2010-04-08 18:52         ` Ingo Molnar
2009-12-23 16:03 Ingo Molnar
2009-10-08 19:01 Ingo Molnar
2009-05-05  9:35 Ingo Molnar
2009-02-17 16:40 [git pull] " Ingo Molnar
2009-02-04 19:18 Ingo Molnar
2009-01-07 22:26 Ingo Molnar
2009-01-07 23:47 ` Linus Torvalds
2009-01-08  7:50   ` Peter Zijlstra
2008-12-04 19:41 Ingo Molnar
2008-04-14 15:07 Ingo Molnar
2008-01-22 10:33 Ingo Molnar
2007-10-29 20:39 [git pull] scheduler fixes Ingo Molnar
2007-10-29 23:34 ` [git pull] scheduler fix Ingo Molnar
2007-10-30 10:15   ` Guillaume Chazarain
2007-11-01  8:39     ` Ingo Molnar

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=20160513185455.GA18742@gmail.com \
    --to=mingo@kernel.org \
    --cc=a.p.zijlstra@chello.nl \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.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).