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[209.132.180.67]) by mx.google.com with ESMTP id x9si36383171plo.98.2019.08.02.05.56.23; Fri, 02 Aug 2019 05:56:24 -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=OBpDVFZI; 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 S2390621AbfHBM4V (ORCPT + 29 others); Fri, 2 Aug 2019 08:56:21 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:56083 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390382AbfHBM4S (ORCPT ); Fri, 2 Aug 2019 08:56:18 -0400 Received: by mail-wm1-f66.google.com with SMTP id a15so67867512wmj.5 for ; Fri, 02 Aug 2019 05:56:16 -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=yjEMe5wuk6zRJXQKT5fhkZ+36XC9uZHCWgmdHyE58XY=; b=OBpDVFZIBBIkpNcqE4jGwaWXitaI6CuguZip4iFoAXWKm8LSDhYbAE2Tm8Nm5hOu6L n6+Bj0rHVMZID2sbxyEjT06dzgqarhID7D5J4TgPbZnrR4nLHu85F3T6erUeUBYxWem8 KuR1vdqRSZL0Gcp5K/CRMXc08PUyBFewGyU2a6QjSrX4UN1wDbgskMuq9ZGCAJRO2OCb 7mG0uTSaTgH6rrMb8aEJFxBUZT44+m2tMxAjau92B2RwttZFGM2Hej5S6Ilb8QtoN2r4 XYr3ftU3MdtxrjNUnRv6bXNEddH/aH5QCL3D8x0DyiIaN+rbrwotL4yoHzK5FNpUZEj1 v+Qw== 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=yjEMe5wuk6zRJXQKT5fhkZ+36XC9uZHCWgmdHyE58XY=; b=QzxfZe3JjluSIOXU1usct+ixYTLFeF5uitlk9IXTRuNhsVF0qNciHE6AS8gVEWCi9+ UhG6NunviSOO3qkDoqWiBYPyXa6PzIxKPudV4CrrMVRl2RsiUsr8WR2BbC93AT3VobjG h1AGTq1O7dwgBiEXM6K1EqymHJCgMLyE0FfkfTA+aKtM02p4Zw4cDLnyXa5mvxniQKjJ QjUJOH/mH+hzK3CxaHm1RaSOKcCSayiFpGMW3FwxDQMDMojNH+DNtc4YnmSQrOtcbaou bA131ixGH0ogxkREqok6XRo82j/cMs4SdPKai6FyRupsp5CTsef4V8sPSJTwNxIZL56T FCrA== X-Gm-Message-State: APjAAAWVTc/d25EfN3/I9sIj4HkX2cOAqh8mwp6sf9kt24ZYzBF0gOyb gRk6P9YW3TUdpNd5LDDv4RZ8v/TO5wg= X-Received: by 2002:a1c:3:: with SMTP id 3mr4569287wma.6.1564750575947; Fri, 02 Aug 2019 05:56:15 -0700 (PDT) Received: from localhost.localdomain ([2a01:e0a:f:6020:dfa:cc47:b267:2a71]) by smtp.gmail.com with ESMTPSA id i6sm69543930wrv.47.2019.08.02.05.56.15 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 02 Aug 2019 05:56:15 -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, Vincent Guittot Subject: [PATCH v3] sched/fair: use utilization to select misfit task Date: Fri, 2 Aug 2019 14:56:12 +0200 Message-Id: <1564750572-20251-1-git-send-email-vincent.guittot@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1564670424-26023-9-git-send-email-vincent.guittot@linaro.org> References: <1564670424-26023-9-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 utilization is used to detect a misfit task but the load is then used to select the task on the CPU which can lead to select a small task with high weight instead of the task that triggered the misfit migration. Signed-off-by: Vincent Guittot --- Keep tracking load instead of utilization but check that task doesn't fit CPU's capacity when selecting the task to detach as suggested by Valentin kernel/sched/fair.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) -- 2.7.4 Acked-by: Valentin Schneider diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 53e64a7..8496118 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7487,15 +7487,9 @@ static int detach_tasks(struct lb_env *env) break; case migrate_misfit: - load = task_h_load(p); - - /* - * utilization of misfit task might decrease a bit - * since it has been recorded. Be conservative in the - * condition. - */ - if (load < env->imbalance) - goto next; + /* This is not a misfit task */ + if (task_fits_capacity(p, capacity_of(env->src_cpu))) + goto next; env->imbalance = 0; break;