From patchwork Tue Feb 6 14:41:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick Bellasi X-Patchwork-Id: 127017 Delivered-To: patch@linaro.org Received: by 10.46.124.24 with SMTP id x24csp2981442ljc; Tue, 6 Feb 2018 06:42:23 -0800 (PST) X-Google-Smtp-Source: AH8x227zr+bwsjcnVvxpCpM13s1q4/HFLsHczmzP4JZxFEoSTzI1mtWZaEMRKFJ+bqYw/bOf9SmO X-Received: by 2002:a17:902:49:: with SMTP id 67-v6mr2602266pla.424.1517928143481; Tue, 06 Feb 2018 06:42:23 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1517928143; cv=none; d=google.com; s=arc-20160816; b=V3PTkB5HjdDMnck6ghNiiAQjMIlq+v2sQMRyjED7foF9vYienxvV0lYbSSzta6zuma zol2QiNFfKNpzFEKu8raJECbWhQXGAJvMcOfYqUxKdiMmkfCK8CzpUCcZOoXsjzIHokM /GnHTQQxDq8AYVlMGHgFgtwSnmF1YAGHii4SnnAv8szV0mhO4KnaPWNN/VEEBsLdP2yV pQFQDNHFLN9ey9ELGp7Yj8xfa8s6+fgG4M3eoz9Cu7EypSWJmPb5hJXOi/Dm9/nxN0Qc 8rHLo5jVH+LN9sxAI/dDF4gGnrurmcAQegAyC2uOxeRU0i6JqhDdj7ed1bBRMfg0QbuZ /5fw== 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:arc-authentication-results; bh=SFoiXCZLZJN59JhFFoFn8dAeoYunbtihd3MDS1OoWAA=; b=AZO0OPZqJegvEu+yM1UfVYTQS021eybY3ntClhpAt33UIzB0vtxmdy2vAet9kf7kkl b34vu3Y/ZvRQElx8TmKDL28tiPKs5LkzGzyDrDOn8I+7jLedneEw7ccA9YThSF1snAxr OpQcYKQE28QQ3PfgHKpuSe0V4m12qH1MnCkYdtWfQ4OReGEJMYNmtWG/XNi+bWhoaboX HqRv0HSzhWgqry3FdaWzoPqeL+GrBJWqkGnzQe/g7w4btSnifxm7h5TK7El8IB5E+g7U wAd8xhmfZzwEKYYnKaYXcNd7tYYCDaQ4cHTZIJB6uzCzv7t2hUpiHpgc+htsGCeOGT4f udwg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-pm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-pm-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 10si2500504pfu.318.2018.02.06.06.42.23; Tue, 06 Feb 2018 06:42:23 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-pm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-pm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-pm-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752408AbeBFOmW (ORCPT + 11 others); Tue, 6 Feb 2018 09:42:22 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:38262 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752151AbeBFOlx (ORCPT ); Tue, 6 Feb 2018 09:41:53 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6C6F2164F; Tue, 6 Feb 2018 06:41:52 -0800 (PST) Received: from e110439-lin.cambridge.arm.com (e110439-lin.cambridge.arm.com [10.1.210.68]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E3B713F487; Tue, 6 Feb 2018 06:41:49 -0800 (PST) From: Patrick Bellasi To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Cc: Ingo Molnar , Peter Zijlstra , "Rafael J . Wysocki" , Viresh Kumar , Vincent Guittot , Paul Turner , Dietmar Eggemann , Morten Rasmussen , Juri Lelli , Todd Kjos , Joel Fernandes , Steve Muckle Subject: [PATCH v4 3/3] sched/cpufreq_schedutil: use util_est for OPP selection Date: Tue, 6 Feb 2018 14:41:31 +0000 Message-Id: <20180206144131.31233-4-patrick.bellasi@arm.com> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180206144131.31233-1-patrick.bellasi@arm.com> References: <20180206144131.31233-1-patrick.bellasi@arm.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org When schedutil looks at the CPU utilization, the current PELT value for that CPU is returned straight away. In certain scenarios this can have undesired side effects and delays on frequency selection. For example, since the task utilization is decayed at wakeup time, a long sleeping big task newly enqueued does not add immediately a significant contribution to the target CPU. This introduces some latency before schedutil will be able to detect the best frequency required by that task. Moreover, the PELT signal build-up time is a function of the current frequency, because of the scale invariant load tracking support. Thus, starting from a lower frequency, the utilization build-up time will increase even more and further delays the selection of the actual frequency which better serves the task requirements. In order to reduce this kind of latencies, we integrate the usage of the CPU's estimated utilization in the sugov_get_util function. This allows to properly consider the expected utilization of a CPU which, for example, has just got a big task running after a long sleep period. Ultimately this allows to select the best frequency to run a task right after its wake-up. Signed-off-by: Patrick Bellasi Reviewed-by: Dietmar Eggemann Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Viresh Kumar Cc: Paul Turner Cc: Vincent Guittot Cc: Morten Rasmussen Cc: Dietmar Eggemann Cc: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org --- Changes in v4: - rebased on today's tip/sched/core (commit 460e8c3340a2) - use util_est.enqueued for cfs_rq's util_est (Joel) - simplify cpu_util_cfs() integration (Dietmar) Changes in v3: - rebase on today's tip/sched/core (commit 07881166a892) - moved into Juri's cpu_util_cfs(), which should also address Rafael's suggestion to use a local variable. Changes in v2: - rebase on top of v4.15-rc2 - tested that overhauled PELT code does not affect the util_est Change-Id: I62c01ed90d8ad45b06383be03d39fcf8c9041646 --- kernel/sched/sched.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) -- 2.15.1 Acked-by: Rafael J. Wysocki diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 2e95505e23c6..f3c7b6a83ef4 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2127,7 +2127,12 @@ static inline unsigned long cpu_util_dl(struct rq *rq) static inline unsigned long cpu_util_cfs(struct rq *rq) { - return rq->cfs.avg.util_avg; + if (!sched_feat(UTIL_EST)) + return rq->cfs.avg.util_avg; + + return max_t(unsigned long, + rq->cfs.avg.util_avg, + rq->cfs.avg.util_est.enqueued); } #endif