From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754301AbaEHKnx (ORCPT ); Thu, 8 May 2014 06:43:53 -0400 Received: from terminus.zytor.com ([198.137.202.10]:33189 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753907AbaEHKnv (ORCPT ); Thu, 8 May 2014 06:43:51 -0400 Date: Thu, 8 May 2014 03:42:53 -0700 From: tip-bot for Rik van Riel Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, riel@redhat.com, chegu_vinod@hp.com, mgorman@suse.de, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, riel@redhat.com, chegu_vinod@hp.com, mgorman@suse.de, tglx@linutronix.de In-Reply-To: <1397235629-16328-3-git-send-email-riel@redhat.com> References: <1397235629-16328-3-git-send-email-riel@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/numa: Retry placement more frequently when misplaced Git-Commit-ID: 5085e2a328849bdee6650b32d52c87c3788ab01c 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: 5085e2a328849bdee6650b32d52c87c3788ab01c Gitweb: http://git.kernel.org/tip/5085e2a328849bdee6650b32d52c87c3788ab01c Author: Rik van Riel AuthorDate: Fri, 11 Apr 2014 13:00:28 -0400 Committer: Ingo Molnar CommitDate: Wed, 7 May 2014 13:33:46 +0200 sched/numa: Retry placement more frequently when misplaced When tasks have not converged on their preferred nodes yet, we want to retry fairly often, to make sure we do not migrate a task's memory to an undesirable location, only to have to move it again later. This patch reduces the interval at which migration is retried, when the task's numa_scan_period is small. Signed-off-by: Rik van Riel Tested-by: Vinod Chegu Acked-by: Mel Gorman Signed-off-by: Peter Zijlstra Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1397235629-16328-3-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f6457b6..ecea8d9 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1326,12 +1326,15 @@ static int task_numa_migrate(struct task_struct *p) /* Attempt to migrate a task to a CPU on the preferred node. */ static void numa_migrate_preferred(struct task_struct *p) { + unsigned long interval = HZ; + /* This task has no NUMA fault statistics yet */ if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults_memory)) return; /* Periodically retry migrating the task to the preferred node */ - p->numa_migrate_retry = jiffies + HZ; + interval = min(interval, msecs_to_jiffies(p->numa_scan_period) / 16); + p->numa_migrate_retry = jiffies + interval; /* Success if task is already running on preferred CPU */ if (task_node(p) == p->numa_preferred_nid)