Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753998AbaBQB4i (ORCPT ); Sun, 16 Feb 2014 20:56:38 -0500 Received: from mail-pb0-f48.google.com ([209.85.160.48]:53439 "EHLO mail-pb0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753127AbaBQB4d (ORCPT ); Sun, 16 Feb 2014 20:56:33 -0500 From: Alex Shi To: mingo@redhat.com, peterz@infradead.org, morten.rasmussen@arm.com Cc: vincent.guittot@linaro.org, daniel.lezcano@linaro.org, fweisbec@gmail.com, linux@arm.linux.org.uk, tony.luck@intel.com, fenghua.yu@intel.com, james.hogan@imgtec.com, alex.shi@linaro.org, jason.low2@hp.com, viresh.kumar@linaro.org, hanjun.guo@linaro.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, akpm@linux-foundation.org, arjan@linux.intel.com, pjt@google.com, fengguang.wu@intel.com, linaro-kernel@lists.linaro.org, wangyun@linux.vnet.ibm.com Subject: [PATCH v2 04/11] sched: unify imbalance bias for target group Date: Mon, 17 Feb 2014 09:55:10 +0800 Message-Id: <1392602117-20773-5-git-send-email-alex.shi@linaro.org> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1392602117-20773-1-git-send-email-alex.shi@linaro.org> References: <1392602117-20773-1-git-send-email-alex.shi@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Old code considers the bias in source/target_load already. but still use imbalance_pct as last check in idlest/busiest group finding. It is also a kind of redundant job. If we bias imbalance in source/target_load, we'd better not use imbalance_pct again. After cpu_load array removed, it is nice time to unify the target bias consideration. So I remove the imbalance_pct from last check and add the live bias using. Signed-off-by: Alex Shi --- kernel/sched/fair.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index eeffe75..a85a10b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1016,7 +1016,7 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page, static unsigned long weighted_cpuload(const int cpu); static unsigned long source_load(int cpu); -static unsigned long target_load(int cpu); +static unsigned long target_load(int cpu, int imbalance_pct); static unsigned long power_of(int cpu); static long effective_load(struct task_group *tg, int cpu, long wl, long wg); @@ -3967,7 +3967,7 @@ static unsigned long source_load(int cpu) * Return a high guess at the load of a migration-target cpu weighted * according to the scheduling class and "nice" value. */ -static unsigned long target_load(int cpu) +static unsigned long target_load(int cpu, int imbalance_pct) { struct rq *rq = cpu_rq(cpu); unsigned long total = weighted_cpuload(cpu); @@ -3975,6 +3975,11 @@ static unsigned long target_load(int cpu) if (!sched_feat(LB_BIAS)) return total; + /* + * Bias target load with imbalance_pct. + */ + total = total * imbalance_pct / 100; + return max(rq->cpu_load, total); } @@ -4180,6 +4185,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) struct task_group *tg; unsigned long weight; int balanced; + int bias = 100 + (sd->imbalance_pct - 100) / 2; /* * If we wake multiple tasks be careful to not bounce @@ -4191,7 +4197,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) this_cpu = smp_processor_id(); prev_cpu = task_cpu(p); load = source_load(prev_cpu); - this_load = target_load(this_cpu); + this_load = target_load(this_cpu, bias); /* * If sync wakeup then subtract the (maximum possible) @@ -4226,7 +4232,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) this_eff_load *= this_load + effective_load(tg, this_cpu, weight, weight); - prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2; + prev_eff_load = bias; prev_eff_load *= power_of(this_cpu); prev_eff_load *= load + effective_load(tg, prev_cpu, 0, weight); @@ -4247,7 +4253,8 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) if (balanced || (this_load <= load && - this_load + target_load(prev_cpu) <= tl_per_task)) { + this_load + target_load(prev_cpu, sd->imbalance_pct) + <= tl_per_task)) { /* * This domain has SD_WAKE_AFFINE and * p is cache cold in this domain, and @@ -4293,7 +4300,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) if (local_group) load = source_load(i); else - load = target_load(i); + load = target_load(i, imbalance); avg_load += load; } @@ -4309,7 +4316,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) } } while (group = group->next, group != sd->groups); - if (!idlest || 100*this_load < imbalance*min_load) + if (!idlest || this_load < min_load) return NULL; return idlest; } @@ -5745,6 +5752,7 @@ static inline void update_sg_lb_stats(struct lb_env *env, { unsigned long load; int i; + int bias = 100 + (env->sd->imbalance_pct - 100) / 2; memset(sgs, 0, sizeof(*sgs)); @@ -5752,8 +5760,8 @@ static inline void update_sg_lb_stats(struct lb_env *env, struct rq *rq = cpu_rq(i); /* Bias balancing toward cpus of our domain */ - if (local_group) - load = target_load(i); + if (local_group && env->idle != CPU_IDLE) + load = target_load(i, bias); else load = source_load(i); @@ -6193,14 +6201,6 @@ static struct sched_group *find_busiest_group(struct lb_env *env) if ((local->idle_cpus < busiest->idle_cpus) && busiest->sum_nr_running <= busiest->group_weight) goto out_balanced; - } else { - /* - * In the CPU_NEWLY_IDLE, CPU_NOT_IDLE cases, use - * imbalance_pct to be conservative. - */ - if (100 * busiest->avg_load <= - env->sd->imbalance_pct * local->avg_load) - goto out_balanced; } force_balance: -- 1.8.1.2 -- 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/