Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752138Ab3IJJd3 (ORCPT ); Tue, 10 Sep 2013 05:33:29 -0400 Received: from cantor2.suse.de ([195.135.220.15]:57356 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751736Ab3IJJdY (ORCPT ); Tue, 10 Sep 2013 05:33:24 -0400 From: Mel Gorman To: Peter Zijlstra , Rik van Riel Cc: Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML , Mel Gorman Subject: [PATCH 49/50] sched: numa: fix task or group comparison Date: Tue, 10 Sep 2013 10:32:29 +0100 Message-Id: <1378805550-29949-50-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1378805550-29949-1-git-send-email-mgorman@suse.de> References: <1378805550-29949-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3083 Lines: 93 From: Rik van Riel This patch should probably be folded into commit 77e0ecbbc5cf0a84764be88b9de5ff13e4338163 Author: Rik van Riel Date: Tue Aug 27 21:52:47 2013 +0100 sched: numa: Decide whether to favour task or group weights based on swap candidate relationships This patch separately considers task and group affinities when searching for swap candidates during NUMA placement. If tasks are part of the same group, or no group at all, the task weights are considered. Some hysteresis is added to prevent tasks within one group from getting bounced between NUMA nodes due to tiny differences. If tasks are part of different groups, the code compares group weights, in order to favor grouping task groups together. The patch also changes the group weight multiplier to be the same as the task weight multiplier, since the two are no longer added up like before. Signed-off-by: Rik van Riel Signed-off-by: Mel Gorman --- kernel/sched/fair.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index fdb7923..ac7184d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -962,7 +962,7 @@ static inline unsigned long group_weight(struct task_struct *p, int nid) if (!total_faults) return 0; - return 1200 * group_faults(p, nid) / total_faults; + return 1000 * group_faults(p, nid) / total_faults; } static unsigned long weighted_cpuload(const int cpu); @@ -1068,16 +1068,34 @@ static void task_numa_compare(struct task_numa_env *env, /* * If dst and source tasks are in the same NUMA group, or not - * in any group then look only at task weights otherwise give - * priority to the group weights. + * in any group then look only at task weights. */ - if (!cur->numa_group || ! env->p->numa_group || - cur->numa_group == env->p->numa_group) { + if (cur->numa_group == env->p->numa_group) { imp = taskimp + task_weight(cur, env->src_nid) - task_weight(cur, env->dst_nid); + /* + * Add some hysteresis to prevent swapping the + * tasks within a group over tiny differences. + */ + if (cur->numa_group) + imp -= imp/16; } else { - imp = groupimp + group_weight(cur, env->src_nid) - - group_weight(cur, env->dst_nid); + /* + * Compare the group weights. If a task is all by + * itself (not part of a group), use the task weight + * instead. + */ + if (env->p->numa_group) + imp = groupimp; + else + imp = taskimp; + + if (cur->numa_group) + imp += group_weight(cur, env->src_nid) - + group_weight(cur, env->dst_nid); + else + imp += task_weight(cur, env->src_nid) - + task_weight(cur, env->dst_nid); } } -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/