From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753811Ab3GPIXw (ORCPT ); Tue, 16 Jul 2013 04:23:52 -0400 Received: from cantor2.suse.de ([195.135.220.15]:48218 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753219Ab3GPIXt (ORCPT ); Tue, 16 Jul 2013 04:23:49 -0400 Date: Tue, 16 Jul 2013 09:23:42 +0100 From: Mel Gorman To: Peter Zijlstra Cc: Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML Subject: Re: [PATCH 16/18] sched: Avoid overloading CPUs on a preferred NUMA node Message-ID: <20130716082342.GF5055@suse.de> References: <1373901620-2021-1-git-send-email-mgorman@suse.de> <1373901620-2021-17-git-send-email-mgorman@suse.de> <20130715200321.GN17211@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20130715200321.GN17211@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 15, 2013 at 10:03:21PM +0200, Peter Zijlstra wrote: > On Mon, Jul 15, 2013 at 04:20:18PM +0100, Mel Gorman wrote: > > --- > > kernel/sched/fair.c | 105 +++++++++++++++++++++++++++++++++++++++++----------- > > 1 file changed, 83 insertions(+), 22 deletions(-) > > > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > > index 3f0519c..8ee1c8e 100644 > > --- a/kernel/sched/fair.c > > +++ b/kernel/sched/fair.c > > @@ -846,29 +846,92 @@ static inline int task_faults_idx(int nid, int priv) > > return 2 * nid + priv; > > } > > > > -static unsigned long weighted_cpuload(const int cpu); > > +static unsigned long source_load(int cpu, int type); > > +static unsigned long target_load(int cpu, int type); > > +static unsigned long power_of(int cpu); > > +static long effective_load(struct task_group *tg, int cpu, long wl, long wg); > > + > > +static int task_numa_find_cpu(struct task_struct *p, int nid) > > +{ > > + int node_cpu = cpumask_first(cpumask_of_node(nid)); > > + int cpu, src_cpu = task_cpu(p), dst_cpu = src_cpu; > > + unsigned long src_load, dst_load; > > + unsigned long min_load = ULONG_MAX; > > + struct task_group *tg = task_group(p); > > + s64 src_eff_load, dst_eff_load; > > + struct sched_domain *sd; > > + unsigned long weight; > > + bool balanced; > > + int imbalance_pct, idx = -1; > > > > + /* No harm being optimistic */ > > + if (idle_cpu(node_cpu)) > > + return node_cpu; > > > > + /* > > + * Find the lowest common scheduling domain covering the nodes of both > > + * the CPU the task is currently running on and the target NUMA node. > > + */ > > + rcu_read_lock(); > > + for_each_domain(src_cpu, sd) { > > + if (cpumask_test_cpu(node_cpu, sched_domain_span(sd))) { > > + /* > > + * busy_idx is used for the load decision as it is the > > + * same index used by the regular load balancer for an > > + * active cpu. > > + */ > > + idx = sd->busy_idx; > > + imbalance_pct = sd->imbalance_pct; > > + break; > > + } > > + } > > + rcu_read_unlock(); > > > > + if (WARN_ON_ONCE(idx == -1)) > > + return src_cpu; > > > > + /* > > + * XXX the below is mostly nicked from wake_affine(); we should > > + * see about sharing a bit if at all possible; also it might want > > + * some per entity weight love. > > + */ > > + weight = p->se.load.weight; > > > > + src_load = source_load(src_cpu, idx); > > + > > + src_eff_load = 100 + (imbalance_pct - 100) / 2; > > + src_eff_load *= power_of(src_cpu); > > + src_eff_load *= src_load + effective_load(tg, src_cpu, -weight, -weight); > > So did you try with this effective_load() term 'missing'? > Yes, it performed worse in tests. Looking at it, I figured that it would have to perform worse unless effective_load regularly returns negative values. -- Mel Gorman SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx184.postini.com [74.125.245.184]) by kanga.kvack.org (Postfix) with SMTP id 570836B0032 for ; Tue, 16 Jul 2013 04:23:49 -0400 (EDT) Date: Tue, 16 Jul 2013 09:23:42 +0100 From: Mel Gorman Subject: Re: [PATCH 16/18] sched: Avoid overloading CPUs on a preferred NUMA node Message-ID: <20130716082342.GF5055@suse.de> References: <1373901620-2021-1-git-send-email-mgorman@suse.de> <1373901620-2021-17-git-send-email-mgorman@suse.de> <20130715200321.GN17211@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20130715200321.GN17211@twins.programming.kicks-ass.net> Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML On Mon, Jul 15, 2013 at 10:03:21PM +0200, Peter Zijlstra wrote: > On Mon, Jul 15, 2013 at 04:20:18PM +0100, Mel Gorman wrote: > > --- > > kernel/sched/fair.c | 105 +++++++++++++++++++++++++++++++++++++++++----------- > > 1 file changed, 83 insertions(+), 22 deletions(-) > > > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > > index 3f0519c..8ee1c8e 100644 > > --- a/kernel/sched/fair.c > > +++ b/kernel/sched/fair.c > > @@ -846,29 +846,92 @@ static inline int task_faults_idx(int nid, int priv) > > return 2 * nid + priv; > > } > > > > -static unsigned long weighted_cpuload(const int cpu); > > +static unsigned long source_load(int cpu, int type); > > +static unsigned long target_load(int cpu, int type); > > +static unsigned long power_of(int cpu); > > +static long effective_load(struct task_group *tg, int cpu, long wl, long wg); > > + > > +static int task_numa_find_cpu(struct task_struct *p, int nid) > > +{ > > + int node_cpu = cpumask_first(cpumask_of_node(nid)); > > + int cpu, src_cpu = task_cpu(p), dst_cpu = src_cpu; > > + unsigned long src_load, dst_load; > > + unsigned long min_load = ULONG_MAX; > > + struct task_group *tg = task_group(p); > > + s64 src_eff_load, dst_eff_load; > > + struct sched_domain *sd; > > + unsigned long weight; > > + bool balanced; > > + int imbalance_pct, idx = -1; > > > > + /* No harm being optimistic */ > > + if (idle_cpu(node_cpu)) > > + return node_cpu; > > > > + /* > > + * Find the lowest common scheduling domain covering the nodes of both > > + * the CPU the task is currently running on and the target NUMA node. > > + */ > > + rcu_read_lock(); > > + for_each_domain(src_cpu, sd) { > > + if (cpumask_test_cpu(node_cpu, sched_domain_span(sd))) { > > + /* > > + * busy_idx is used for the load decision as it is the > > + * same index used by the regular load balancer for an > > + * active cpu. > > + */ > > + idx = sd->busy_idx; > > + imbalance_pct = sd->imbalance_pct; > > + break; > > + } > > + } > > + rcu_read_unlock(); > > > > + if (WARN_ON_ONCE(idx == -1)) > > + return src_cpu; > > > > + /* > > + * XXX the below is mostly nicked from wake_affine(); we should > > + * see about sharing a bit if at all possible; also it might want > > + * some per entity weight love. > > + */ > > + weight = p->se.load.weight; > > > > + src_load = source_load(src_cpu, idx); > > + > > + src_eff_load = 100 + (imbalance_pct - 100) / 2; > > + src_eff_load *= power_of(src_cpu); > > + src_eff_load *= src_load + effective_load(tg, src_cpu, -weight, -weight); > > So did you try with this effective_load() term 'missing'? > Yes, it performed worse in tests. Looking at it, I figured that it would have to perform worse unless effective_load regularly returns negative values. -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org