From patchwork Thu Jun 25 06:46:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Wang X-Patchwork-Id: 11624653 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 81D9214F6 for ; Thu, 25 Jun 2020 06:46:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 68121207FC for ; Thu, 25 Jun 2020 06:46:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Gc4Yxt3I" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390087AbgFYGqX (ORCPT ); Thu, 25 Jun 2020 02:46:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60088 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389962AbgFYGqW (ORCPT ); Thu, 25 Jun 2020 02:46:22 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D36E7C0613ED for ; Wed, 24 Jun 2020 23:46:20 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id e20so4893705ybc.23 for ; Wed, 24 Jun 2020 23:46:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:cc; bh=9en45t/QzNaNM6uWfEIwyjVyBid8D5wBKicPYDDrGpo=; b=Gc4Yxt3I7/UcYTu0bsH1RFH6diu2RtYT0O5GLSOd5lrZmADKnymrdsOeLqV7AlTUZP djUwVJ5/iT8vzS/u1jfong1rtooTiqAFZsJNVZ/160i+YN93vacdCFS1xcNRwfGJX5np BfgeCY4eblYzBNNzloHFyKelqnmsz1OWakPsArY7nfTdJSHMhy1F0VirmZLWRc1m9LVu 5Rb/mm2BR1sZqZ1pSoqr2TPS/SUpYzn3FuzU74kQWex+UPMJZgn0FzjcI9WiuSuEwNNg TiZC21Nfi2SFU+LhECZz9cL8/tcQ4maAyHFNYis0t157qx0PFD3Ewl/A6us03VBPRj5u fv1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:cc; bh=9en45t/QzNaNM6uWfEIwyjVyBid8D5wBKicPYDDrGpo=; b=VGrRX2BX+zpCgVLOuKdSO28GyXK1Y82SO0eRyGhofhnG1J337uMoQSNnChiP3M+aQX fdF9BjrUTZwQcCPdJmv5aoz84uA96qfaHrp7sRmfpkFwtrqNbBHxHKkC9hH/h4uLXvAi CXEIyHjbJhASvo38sytkux0ZNJsUYcWWe6xCOv25Vj96LQ1Yo4XvKvN4lVnGpH1D8uHV Ni6tkNUkkTrcMP06kaBHh8s+0QkzOHvD/EuXYsaf43l3y5MI5fx2NvOTL1TKxR+24aGf SZjGHHijP3ygrveBeOd7Xj+enkXzs/7Jkl6xBBOEXUmQ0byskcNY5Ci9HIuL57npjTs/ 6hAg== X-Gm-Message-State: AOAM531dGTt9iU2bU95kHvmgjMAhvn7pCqLKI29mzevSx/ZRa6DyagCP l6uLyud/SLA6Q/Qq7iEFI6h4CXE= X-Google-Smtp-Source: ABdhPJyvtkM8ik0DG/iBtJ1DhvVo8taVGremx1Ji24BaU8j0zc+CEhOAi7JnDBoNVfaMjxe8JjbuDbE= X-Received: by 2002:a25:be05:: with SMTP id h5mr49833690ybk.131.1593067579604; Wed, 24 Jun 2020 23:46:19 -0700 (PDT) Date: Wed, 24 Jun 2020 23:46:14 -0700 Message-Id: <20200625064614.101183-1-wvw@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.27.0.212.ge8ba1cc988-goog Subject: [PATCH] cpufreq: schedutil: force frequency update when limits change From: Wei Wang Cc: wei.vince.wang@gmail.com, dsmythies@telus.net, viresh.kumar@linaro.org, Wei Wang , "Rafael J. Wysocki" , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , "Joel Fernandes (Google)" , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org To: unlisted-recipients:; (no To-header on input) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org To avoid reducing the frequency of a CPU prematurely, we skip reducing the frequency if the CPU had been busy recently. This should not be done when the limits of the policy are changed, for example due to thermal throttling. We should always get the frequency within the new limits as soon as possible. There was a fix in commit 600f5badb78c ("cpufreq: schedutil: Don't skip freq update when limits change") upstream which introduced another flag. However, the fix didn't address the case when next_freq is the same as previously voted, which is then checked in sugov_update_next_freq. As a result, the frequency would be stuck at low until the high demanding workload quits. test trace: kworker/u19:0-1872 ( 1872) [002] .... 347.878871: cpu_frequency_limits: min=600000 max=2348000 cpu_id=6 dhry64-11525 (11525) [007] d.h2 347.880012: sugov_should_update_freq: thermal limit on policy6 dhry64-11525 (11525) [007] d.h2 347.880012: sugov_deferred_update: policy6 skipped update dhry64-11525 (11525) [007] d.h2 347.884040: sugov_deferred_update: policy6 skipped update ... This patch fixes this by skipping the check and forcing an update in this case. The second flag was kept as the limits_change flag could be updated in thermal kworker from another CPU. Fixes: ecd288429126 ("cpufreq: schedutil: Don't set next_freq to UINT_MAX") Signed-off-by: Wei Wang --- kernel/sched/cpufreq_schedutil.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 7fbaee24c824..dc2cd768022e 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -102,11 +102,12 @@ static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time) static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time, unsigned int next_freq) { - if (sg_policy->next_freq == next_freq) + if (!sg_policy->need_freq_update && sg_policy->next_freq == next_freq) return false; sg_policy->next_freq = next_freq; sg_policy->last_freq_update_time = time; + sg_policy->need_freq_update = false; return true; } @@ -178,7 +179,6 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update) return sg_policy->next_freq; - sg_policy->need_freq_update = false; sg_policy->cached_raw_freq = freq; return cpufreq_driver_resolve_freq(policy, freq); }