From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932421AbaESNMa (ORCPT ); Mon, 19 May 2014 09:12:30 -0400 Received: from terminus.zytor.com ([198.137.202.10]:59518 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932398AbaESNMW (ORCPT ); Mon, 19 May 2014 09:12:22 -0400 Date: Mon, 19 May 2014 06:11:21 -0700 From: tip-bot for Rik van Riel Message-ID: Cc: linux-kernel@vger.kernel.org, riel@redhat.com, hpa@zytor.com, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, riel@redhat.com, linux-kernel@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de In-Reply-To: <20140516001332.67f91af2@annuminas.surriel.com> References: <20140516001332.67f91af2@annuminas.surriel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched,numa: Decay wakee_flips instead of zeroing Git-Commit-ID: 5658b4f43e63f8c7b4a27995dcb2cf43a52ee398 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 5658b4f43e63f8c7b4a27995dcb2cf43a52ee398 Gitweb: http://git.kernel.org/tip/5658b4f43e63f8c7b4a27995dcb2cf43a52ee398 Author: Rik van Riel AuthorDate: Fri, 16 May 2014 00:13:32 -0400 Committer: Thomas Gleixner CommitDate: Mon, 19 May 2014 22:02:43 +0900 sched,numa: Decay wakee_flips instead of zeroing Affine wakeups have the potential to interfere with NUMA placement. If a task wakes up too many other tasks, affine wakeups will get disabled. However, regardless of how many other tasks it wakes up, it gets re-enabled once a second, potentially interfering with NUMA placement of other tasks. By decaying wakee_wakes in half instead of zeroing it, we can avoid that problem for some workloads. Cc: chegu_vinod@hp.com Cc: mingo@kernel.org Cc: umgwanakikbuti@gmail.com Signed-off-by: Rik van Riel Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20140516001332.67f91af2@annuminas.surriel.com Signed-off-by: Thomas Gleixner --- 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 503f750..c9617b7 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4065,7 +4065,7 @@ static void record_wakee(struct task_struct *p) * about the loss. */ if (jiffies > current->wakee_flip_decay_ts + HZ) { - current->wakee_flips = 0; + current->wakee_flips >>= 1; current->wakee_flip_decay_ts = jiffies; }