From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751658AbaFDUdf (ORCPT ); Wed, 4 Jun 2014 16:33:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34356 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751405AbaFDUde (ORCPT ); Wed, 4 Jun 2014 16:33:34 -0400 Date: Wed, 4 Jun 2014 16:33:15 -0400 From: Rik van Riel To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, mgorman@suse.de, mingo@kernel.org Subject: [PATCH] sched,numa: always try to migrate to preferred node at task_numa_placement time Message-ID: <20140604163315.1dbc7b56@cuia.bos.redhat.com> Organization: Red Hat, Inc MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is possible that at task_numa_placement time, the task's numa_preferred_nid does not change, but the task is not actually running on the preferred node at the time. In that case, we still want to attempt migration to the preferred node. Signed-off-by: Rik van Riel --- kernel/sched/fair.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 0fdb96d..708c6a9 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1575,11 +1575,13 @@ static void task_numa_placement(struct task_struct *p) spin_unlock_irq(group_lock); } - /* Preferred node as the node with the most faults */ - if (max_faults && max_nid != p->numa_preferred_nid) { - /* Update the preferred nid and migrate task if possible */ - sched_setnuma(p, max_nid); - numa_migrate_preferred(p); + if (max_faults) { + /* Set the new preferred node */ + if (max_nid != p->numa_preferred_nid) + sched_setnuma(p, max_nid); + + if (task_node(p) != p->numa_preferred_nid) + numa_migrate_preferred(p); } }