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[209.132.180.67]) by mx.google.com with ESMTP id j14si4683323eda.181.2019.09.19.00.34.10; Thu, 19 Sep 2019 00:34:10 -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=Msd7C7Yg; 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 S2388652AbfISHeJ (ORCPT + 26 others); Thu, 19 Sep 2019 03:34:09 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:45539 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388627AbfISHeH (ORCPT ); Thu, 19 Sep 2019 03:34:07 -0400 Received: by mail-wr1-f67.google.com with SMTP id r5so1880273wrm.12 for ; Thu, 19 Sep 2019 00:34:06 -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=kRzPPO6auHhE/DujuF4oxr11CuUWI/AICc91av/Y9I8=; b=Msd7C7YgcknAK6Jfv3VHjT2ctWoJqZl8q7RbneMRKIIwnsAlECkOyIaISFN18R2H4p Z06DTe5L0CaYseMfh8g1bEgjBTXHlxi5Aij3602uqqrk8IUILjtF/8Mipe9d8aDN7OIq zYeg3bdV7llUY8F3uFIxCaPy6WUAI7PKxkeFx+BMJeaXciBd6Hi3AAon5ILdmycMiXHO aTpN1fz8r6gA128dMW3z1xDtKTztiu90PC7ze+dzmwn3OLIExhbfZxK+hdIwD0Plrh2s a0+ckgV0vOMkT13GBBxADDSC4w0EBQQeSWyKumJMJmGMtI5gt+c5TuD2a9xQr/Gp2lp/ kiow== 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=kRzPPO6auHhE/DujuF4oxr11CuUWI/AICc91av/Y9I8=; b=j10nI44eflN3IpECOYjdJz5VKnynma9qG5Nju4YMaiwSB0oSNCNVRa1+8yuPjzqSYg VCgNw84aOYagQUKPXwYwjlrbE58jlMhLsX9/UwpKNkA2T/F5WcPEtmXjbWVO4zSV6WbN ItpvFv6BoHsc/Fu7WpKaQGfzrSzOrmJN/JDLkogoJlMC9ZlaskqOzON2H8D8MhNK0bqc YtG0vZ5jUMyZ3egEMpy3oWNRVhQKLIaXScv3X9/PdhQhxT5YY52claVSnvbjQm2lIs/S aOmQkVUoFynHNpPh297VsfMzNfoB8Wfrhuh1aYlnzZorG8JmTFSma36qyQ6owFommlJX 7NaQ== X-Gm-Message-State: APjAAAVt1oH0IIpguKlcvvytgmiF2kX37HeZao3t00EsCXGY8I85UOVc yygjhHyIhbemBYpVw4k0uKPi9NBSsgY= X-Received: by 2002:adf:f008:: with SMTP id j8mr6400595wro.75.1568878445082; Thu, 19 Sep 2019 00:34:05 -0700 (PDT) Received: from localhost.localdomain ([2a01:e0a:f:6020:d555:8fca:a19c:222c]) by smtp.gmail.com with ESMTPSA id s12sm13300250wra.82.2019.09.19.00.34.03 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 19 Sep 2019 00:34:03 -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 05/10] sched/fair: use rq->nr_running when balancing load Date: Thu, 19 Sep 2019 09:33:36 +0200 Message-Id: <1568878421-12301-6-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 cfs load_balance only takes care of CFS tasks whereas CPUs can be used by other scheduling class. Typically, a CFS task preempted by a RT or deadline task will not get a chance to be pulled on another CPU because the load_balance doesn't take into account tasks from other classes. Add sum of nr_running in the statistics and use it to detect such situation. Signed-off-by: Vincent Guittot --- kernel/sched/fair.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) -- 2.7.4 diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d33379c..7e74836 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7716,6 +7716,7 @@ struct sg_lb_stats { unsigned long group_load; /* Total load over the CPUs of the group */ unsigned long group_capacity; unsigned long group_util; /* Total utilization of the group */ + unsigned int sum_nr_running; /* Nr of tasks running in the group */ unsigned int sum_h_nr_running; /* Nr of CFS tasks running in the group */ unsigned int idle_cpus; unsigned int group_weight; @@ -7949,7 +7950,7 @@ static inline int sg_imbalanced(struct sched_group *group) static inline bool group_has_capacity(struct lb_env *env, struct sg_lb_stats *sgs) { - if (sgs->sum_h_nr_running < sgs->group_weight) + if (sgs->sum_nr_running < sgs->group_weight) return true; if ((sgs->group_capacity * 100) > @@ -7970,7 +7971,7 @@ group_has_capacity(struct lb_env *env, struct sg_lb_stats *sgs) static inline bool group_is_overloaded(struct lb_env *env, struct sg_lb_stats *sgs) { - if (sgs->sum_h_nr_running <= sgs->group_weight) + if (sgs->sum_nr_running <= sgs->group_weight) return false; if ((sgs->group_capacity * 100) < @@ -8074,6 +8075,8 @@ static inline void update_sg_lb_stats(struct lb_env *env, sgs->sum_h_nr_running += rq->cfs.h_nr_running; nr_running = rq->nr_running; + sgs->sum_nr_running += nr_running; + if (nr_running > 1) *sg_status |= SG_OVERLOAD; @@ -8423,7 +8426,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s * groups. */ env->balance_type = migrate_task; - env->imbalance = (busiest->sum_h_nr_running - local->sum_h_nr_running) >> 1; + env->imbalance = (busiest->sum_nr_running - local->sum_nr_running) >> 1; return; } @@ -8585,7 +8588,7 @@ static struct sched_group *find_busiest_group(struct lb_env *env) /* Try to move all excess tasks to child's sibling domain */ if (sds.prefer_sibling && local->group_type == group_has_spare && - busiest->sum_h_nr_running > local->sum_h_nr_running + 1) + busiest->sum_nr_running > local->sum_nr_running + 1) goto force_balance; if (busiest->group_type != group_overloaded &&