From patchwork Thu Sep 19 07:33:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincent Guittot X-Patchwork-Id: 174038 Delivered-To: patch@linaro.org Received: by 2002:a92:7e96:0:0:0:0:0 with SMTP id q22csp664010ill; Thu, 19 Sep 2019 00:34:04 -0700 (PDT) X-Google-Smtp-Source: APXvYqwMxI1YYO1ZMWn1HQEPFvNn0d5CYIDZC4a526Bsy++YscwLrx94FMaUu3TvsQy975NerKky X-Received: by 2002:a50:a557:: with SMTP id z23mr14071123edb.99.1568878443941; Thu, 19 Sep 2019 00:34:03 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1568878443; cv=none; d=google.com; s=arc-20160816; b=vEvf68bdnw38opIz4QPK/FfWUjU2nYjGsepP32caP2DxEhNlmEewOX7ZxT877IxVhp Wtql50cLPp/AjtFerBmRpYnzg2ivBcZfP2fAwWlAROtDqJMMbRIWOWhv2j6EnVogo2yW Mzh/0I0myM3+RkIdYZlWPmoaCzcl7BR8AjaJ8ZHiUtyqlZC732Ls7wlwZpIok6pGHSeH 1AoupxO+ETjqrNdLvYGhwPYpx/7PThieMxtFsT2AEZ24N8J+RsM1pOe6WQY/vdh/70UI XIEjwO/vMiZXdYIc3mw3rEi2en0l8b9mH458/xkraxDNuj6Lo3JBRwpp5mT7eeurc9U/ Lo2A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature; bh=Yv6OJ+qJWSUveYSQClIlpg+HtWhIHflpjhPTFDhhWg0=; b=d63Xr/SXJvFwBu47yyiN/Jo88OrWUFsL0Pv3HFgSWW5ZCkv+Rf3BwCTsD5p1Kja8qz LUpbCEMgBsF2cJ5I07UsiTeL6loN8fIZJfJXk6eUDD3RSZiiF0R8WUJZpW67DZtrzvET mzghWM7nEddllWKEWh0n5GCYMI2r8Sor9EcmdGgVJbE1aZu0lPFrQR6nXDvziJuVKXot H86O2siZTLTEIoGN/xN4FQGhzW1wQJb4fP+wEw37HjkVRMdyALyU/RHVTO3aXF30NWhs Is7rIoHgbYI9+W/0UEa77c8/rn4jMYdiFpyKfzcVMZRvZhbrFpfa9vWJkGepqPYsh6ST gtNQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=gU4R5hVl; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id e10si4067126ejf.69.2019.09.19.00.34.03; Thu, 19 Sep 2019 00:34:03 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=gU4R5hVl; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388628AbfISHeC (ORCPT + 26 others); Thu, 19 Sep 2019 03:34:02 -0400 Received: from mail-wm1-f68.google.com ([209.85.128.68]:34669 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387987AbfISHeB (ORCPT ); Thu, 19 Sep 2019 03:34:01 -0400 Received: by mail-wm1-f68.google.com with SMTP id y135so6509467wmc.1 for ; Thu, 19 Sep 2019 00:33:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Yv6OJ+qJWSUveYSQClIlpg+HtWhIHflpjhPTFDhhWg0=; b=gU4R5hVlKT8S03ABoMXLVq+a9wpdo+RCX13F8JEMTiQCW4ZMjIarL6SaDV5qypH8Wd zrhAtU8SDUaELT1tecX1Y+0WNzvBdsPuE47xctMS/zIE7nFrHD/p1uUrkacLbZpXhzHW +JucRgZEomQeGAL/YxQ97GN6gme3eA6WRV0Eo4f1moUCNZCX5cOwE9LBorAbVx0Hp2ft qMX+ngNiNZq4axL611v3eSJ8TU3IH5VowNhLYFmI67gfZOfMdIOPnnLMj0JeTz1i3LJ0 vstNT2HEMmP+Gr/UiNHaAbcvNanVGVCwu6njib1D/bUj4iFie06Q2gULbB0db4t3MpPw fh3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Yv6OJ+qJWSUveYSQClIlpg+HtWhIHflpjhPTFDhhWg0=; b=g4KBgyq0uQo0xLDXlMRroZRVSmvLbd/X/BFLc2pFZBcSTV/toha5Lu1iFevI2a5Rg8 Zgu24xopwEJ7r8QHjrvOY0AiBfCBUClf2tCM75Zgba0stL9LLpn3XLBFegoYM3x2QgKT Plr+K6m4Ia4slL6bOOXuQb1Eg24/bhSJOcQPzvCKDyUyjMJ/m5DVtR9J1gqsR6dhgpij TzIlbQ0Nrveu3lkCpSPaooxUEqlPVsD7rCJzLdMU0SVpJgE5QQSyhuxQTGPbPhmQpCTk kDbeMOJzyYsnw5KAWR1wVRpsUOvhzj2k+nUXwsNMgx1lF6zearA5zVHfHr1VfgWPxQCO V2RA== X-Gm-Message-State: APjAAAW8t0XeBWWhGXeRS8GyJaiJBEOXNXLjeqOXwIzAbBaUospYZk7r lCzpl3miSEKXf9wU5K7YQ86qWxF4ASY= X-Received: by 2002:a1c:f209:: with SMTP id s9mr1614438wmc.60.1568878437850; Thu, 19 Sep 2019 00:33:57 -0700 (PDT) Received: from localhost.localdomain ([2a01:e0a:f:6020:d555:8fca:a19c:222c]) by smtp.gmail.com with ESMTPSA id s12sm13300250wra.82.2019.09.19.00.33.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 19 Sep 2019 00:33:56 -0700 (PDT) From: Vincent Guittot To: linux-kernel@vger.kernel.org, mingo@redhat.com, peterz@infradead.org Cc: pauld@redhat.com, valentin.schneider@arm.com, srikar@linux.vnet.ibm.com, quentin.perret@arm.com, dietmar.eggemann@arm.com, Morten.Rasmussen@arm.com, hdanton@sina.com, Vincent Guittot Subject: [PATCH v3 01/10] sched/fair: clean up asym packing Date: Thu, 19 Sep 2019 09:33:32 +0200 Message-Id: <1568878421-12301-2-git-send-email-vincent.guittot@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1568878421-12301-1-git-send-email-vincent.guittot@linaro.org> References: <1568878421-12301-1-git-send-email-vincent.guittot@linaro.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Clean up asym packing to follow the default load balance behavior: - classify the group by creating a group_asym_packing field. - calculate the imbalance in calculate_imbalance() instead of bypassing it. We don't need to test twice same conditions anymore to detect asym packing and we consolidate the calculation of imbalance in calculate_imbalance(). There is no functional changes. Signed-off-by: Vincent Guittot --- kernel/sched/fair.c | 63 ++++++++++++++--------------------------------------- 1 file changed, 16 insertions(+), 47 deletions(-) -- 2.7.4 Acked-by: Rik van Riel diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 1054d2c..3175fea 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7685,6 +7685,7 @@ struct sg_lb_stats { unsigned int group_weight; enum group_type group_type; int group_no_capacity; + unsigned int group_asym_packing; /* Tasks should be moved to preferred CPU */ unsigned long group_misfit_task_load; /* A CPU has a task too big for its capacity */ #ifdef CONFIG_NUMA_BALANCING unsigned int nr_numa_running; @@ -8139,9 +8140,17 @@ static bool update_sd_pick_busiest(struct lb_env *env, * ASYM_PACKING needs to move all the work to the highest * prority CPUs in the group, therefore mark all groups * of lower priority than ourself as busy. + * + * This is primarily intended to used at the sibling level. Some + * cores like POWER7 prefer to use lower numbered SMT threads. In the + * case of POWER7, it can move to lower SMT modes only when higher + * threads are idle. When in lower SMT modes, the threads will + * perform better since they share less core resources. Hence when we + * have idle threads, we want them to be the higher ones. */ if (sgs->sum_nr_running && sched_asym_prefer(env->dst_cpu, sg->asym_prefer_cpu)) { + sgs->group_asym_packing = 1; if (!sds->busiest) return true; @@ -8283,51 +8292,6 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd } /** - * check_asym_packing - Check to see if the group is packed into the - * sched domain. - * - * This is primarily intended to used at the sibling level. Some - * cores like POWER7 prefer to use lower numbered SMT threads. In the - * case of POWER7, it can move to lower SMT modes only when higher - * threads are idle. When in lower SMT modes, the threads will - * perform better since they share less core resources. Hence when we - * have idle threads, we want them to be the higher ones. - * - * This packing function is run on idle threads. It checks to see if - * the busiest CPU in this domain (core in the P7 case) has a higher - * CPU number than the packing function is being run on. Here we are - * assuming lower CPU number will be equivalent to lower a SMT thread - * number. - * - * Return: 1 when packing is required and a task should be moved to - * this CPU. The amount of the imbalance is returned in env->imbalance. - * - * @env: The load balancing environment. - * @sds: Statistics of the sched_domain which is to be packed - */ -static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds) -{ - int busiest_cpu; - - if (!(env->sd->flags & SD_ASYM_PACKING)) - return 0; - - if (env->idle == CPU_NOT_IDLE) - return 0; - - if (!sds->busiest) - return 0; - - busiest_cpu = sds->busiest->asym_prefer_cpu; - if (sched_asym_prefer(busiest_cpu, env->dst_cpu)) - return 0; - - env->imbalance = sds->busiest_stat.group_load; - - return 1; -} - -/** * fix_small_imbalance - Calculate the minor imbalance that exists * amongst the groups of a sched_domain, during * load balancing. @@ -8411,6 +8375,11 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s local = &sds->local_stat; busiest = &sds->busiest_stat; + if (busiest->group_asym_packing) { + env->imbalance = busiest->group_load; + return; + } + if (busiest->group_type == group_imbalanced) { /* * In the group_imb case we cannot rely on group-wide averages @@ -8515,8 +8484,8 @@ static struct sched_group *find_busiest_group(struct lb_env *env) busiest = &sds.busiest_stat; /* ASYM feature bypasses nice load balance check */ - if (check_asym_packing(env, &sds)) - return sds.busiest; + if (busiest->group_asym_packing) + goto force_balance; /* There is no busy sibling group to pull tasks from */ if (!sds.busiest || busiest->sum_nr_running == 0)