Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752179Ab3IJJdc (ORCPT ); Tue, 10 Sep 2013 05:33:32 -0400 Received: from cantor2.suse.de ([195.135.220.15]:57347 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752117Ab3IJJdY (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 48/50] sched: numa: Decide whether to favour task or group weights based on swap candidate relationships Date: Tue, 10 Sep 2013 10:32:28 +0100 Message-Id: <1378805550-29949-49-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: 5826 Lines: 165 From: Rik van Riel This patch separately considers task and group affinities when searching for swap candidates during task NUMA placement. If tasks are not part of a group or the same group then the task weights are considered. Otherwise the group weights are compared. Not-signed-off-by: Rik van Riel --- kernel/sched/fair.c | 59 ++++++++++++++++++++++++++++++++--------------------- 1 file changed, 36 insertions(+), 23 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 80906fa..fdb7923 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1039,13 +1039,15 @@ static void task_numa_assign(struct task_numa_env *env, * into account that it might be best if task running on the dst_cpu should * be exchanged with the source task */ -static void task_numa_compare(struct task_numa_env *env, long imp) +static void task_numa_compare(struct task_numa_env *env, + long taskimp, long groupimp) { struct rq *src_rq = cpu_rq(env->src_cpu); struct rq *dst_rq = cpu_rq(env->dst_cpu); struct task_struct *cur; long dst_load, src_load; long load; + long imp = (groupimp > 0) ? groupimp : taskimp; rcu_read_lock(); cur = ACCESS_ONCE(dst_rq->curr); @@ -1064,10 +1066,19 @@ static void task_numa_compare(struct task_numa_env *env, long imp) if (!cpumask_test_cpu(env->src_cpu, tsk_cpus_allowed(cur))) goto unlock; - imp += task_weight(cur, env->src_nid) + - group_weight(cur, env->src_nid) - - task_weight(cur, env->dst_nid) - - group_weight(cur, env->dst_nid); + /* + * 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. + */ + if (!cur->numa_group || ! env->p->numa_group || + cur->numa_group == env->p->numa_group) { + imp = taskimp + task_weight(cur, env->src_nid) - + task_weight(cur, env->dst_nid); + } else { + imp = groupimp + group_weight(cur, env->src_nid) - + group_weight(cur, env->dst_nid); + } } if (imp < env->best_imp) @@ -1117,7 +1128,8 @@ unlock: rcu_read_unlock(); } -static void task_numa_find_cpu(struct task_numa_env *env, long imp) +static void task_numa_find_cpu(struct task_numa_env *env, + long taskimp, long groupimp) { int cpu; @@ -1127,7 +1139,7 @@ static void task_numa_find_cpu(struct task_numa_env *env, long imp) continue; env->dst_cpu = cpu; - task_numa_compare(env, imp); + task_numa_compare(env, taskimp, groupimp); } } @@ -1147,9 +1159,9 @@ static int task_numa_migrate(struct task_struct *p) .best_cpu = -1 }; struct sched_domain *sd; - unsigned long weight; + unsigned long taskweight, groupweight; int nid, ret; - long imp; + long taskimp, groupimp; /* * Find the lowest common scheduling domain covering the nodes of both @@ -1164,10 +1176,12 @@ static int task_numa_migrate(struct task_struct *p) } rcu_read_unlock(); - weight = task_weight(p, env.src_nid) + group_weight(p, env.src_nid); + taskweight = task_weight(p, env.src_nid); + groupweight = group_weight(p, env.src_nid); update_numa_stats(&env.src_stats, env.src_nid); env.dst_nid = p->numa_preferred_nid; - imp = task_weight(p, env.dst_nid) + group_weight(p, env.dst_nid) - weight; + taskimp = task_weight(p, env.dst_nid) - taskweight; + groupimp = group_weight(p, env.dst_nid) - groupweight; update_numa_stats(&env.dst_stats, env.dst_nid); /* @@ -1175,20 +1189,21 @@ static int task_numa_migrate(struct task_struct *p) * alternative node with relatively better statistics. */ if (env.dst_stats.has_capacity) { - task_numa_find_cpu(&env, imp); + task_numa_find_cpu(&env, taskimp, groupimp); } else { for_each_online_node(nid) { if (nid == env.src_nid || nid == p->numa_preferred_nid) continue; /* Only consider nodes where both task and groups benefit */ - imp = task_weight(p, nid) + group_weight(p, nid) - weight; - if (imp < 0) + taskimp = task_weight(p, nid) - taskweight; + groupimp = group_weight(p, nid) - groupweight; + if (taskimp < 0 && groupimp < 0) continue; env.dst_nid = nid; update_numa_stats(&env.dst_stats, env.dst_nid); - task_numa_find_cpu(&env, imp); + task_numa_find_cpu(&env, taskimp, groupimp); } } @@ -4627,10 +4642,9 @@ static bool migrate_improves_locality(struct task_struct *p, struct lb_env *env) if (dst_nid == p->numa_preferred_nid) return true; - /* After the task has settled, check if the new node is better. */ - if (p->numa_migrate_seq >= sysctl_numa_balancing_settle_count && - task_weight(p, dst_nid) + group_weight(p, dst_nid) > - task_weight(p, src_nid) + group_weight(p, src_nid)) + /* If both task and group weight improve, this move is a winner. */ + if (task_weight(p, dst_nid) > task_weight(p, src_nid) && + group_weight(p, dst_nid) > group_weight(p, src_nid)) return true; return false; @@ -4657,10 +4671,9 @@ static bool migrate_degrades_locality(struct task_struct *p, struct lb_env *env) if (src_nid == p->numa_preferred_nid) return true; - /* After the task has settled, check if the new node is worse. */ - if (p->numa_migrate_seq >= sysctl_numa_balancing_settle_count && - task_weight(p, dst_nid) + group_weight(p, dst_nid) < - task_weight(p, src_nid) + group_weight(p, src_nid)) + /* If either task or group weight get worse, don't do it. */ + if (task_weight(p, dst_nid) < task_weight(p, src_nid) || + group_weight(p, dst_nid) < group_weight(p, src_nid)) return true; return false; -- 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/