From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8E21C433FE for ; Thu, 10 Nov 2022 19:57:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229952AbiKJT5l (ORCPT ); Thu, 10 Nov 2022 14:57:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229688AbiKJT5k (ORCPT ); Thu, 10 Nov 2022 14:57:40 -0500 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4035B7646 for ; Thu, 10 Nov 2022 11:57:39 -0800 (PST) Received: by mail-pg1-x54a.google.com with SMTP id l63-20020a639142000000b0046f5bbb7372so1474545pge.23 for ; Thu, 10 Nov 2022 11:57:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=2Nv/CBgytn69NMqK+TFbyBd+BfQKl+kVHWTnPjJGMMU=; b=pQY6f1vDAT8XHF59ZRKV9GgCCjpwYTun9sBF+RHq6hglBXJnPyTL8xHYMWvQgzxaCL 9+z7GaGdDxpKBWQa62QPd8TVNNsd3d8BLn8yOV1HUPZmNxLB9Sxz8Bt4+nPxruvDIJTd SRvZwNzqJZVLsgqs3RGK1shyvs/ohYPVqBvfQzrzrXiZu/dxQLYAtSsUGGK5mf5/I8o2 qvykPFapJi956aW1SJgg00q+B/cM4pnCB8wuQAG9HoVNK4K9gD0tN0MZKaT2l1rjyd3O t4pi8PCzgjargodRNZ37Z2BiJPOWolc8LJK9mpHraBoFyazSBp7Wg2ubFPp1fovcY5iC gLDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=2Nv/CBgytn69NMqK+TFbyBd+BfQKl+kVHWTnPjJGMMU=; b=mAzP6Q4nzjnK3QnZizRr19UZagzWDWR52TmVn73yI+OyFU0fCnCL/Zw/lrrgNyo6KS zxV4MRTFTgCIpOpWLRugRj3nZGMOSxmeDnEpWThKiAFf8OPYQFCRFrIH/6dE/GGOiu4r QvUXXnBOMSHdOe6vC1fxjkuVaLCDSnUEPOXIwiWan/nMPk7abCOBLg2t5wJVV9sNfayh eWYdyXwbRO78at1KKawOI1CqOODHwbCo6qlAdOdv6Pwon7edCuhtC4QoA/S1Q7/x5Wpf GRRrNuup8IJp6e8KEzI9WY3t5HetNX/0IwMGNwuXV2tReEiX6iL/1KBTp4PMZ+FWXap0 IyMQ== X-Gm-Message-State: ACrzQf3cFj01Y6hEnct2AmaNQe1yfIaw4fqnpLBi8iP7rbybhf+765Ef H1gCHPNFszr+zMIrBH8m100FK7rx0z0l1Q== X-Google-Smtp-Source: AMsMyM4IJBP4wy9Zci9wBJ4eUvEOuR3adcZ5+nJrkztQfesx0mZ98JTf83ulHfu5O7HqA8IV7eurhuJDP2DcxA== X-Received: from wusamuel-special.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2a8c]) (user=wusamuel job=sendgmr) by 2002:a17:902:b586:b0:187:30f0:b16b with SMTP id a6-20020a170902b58600b0018730f0b16bmr1829832pls.14.1668110258701; Thu, 10 Nov 2022 11:57:38 -0800 (PST) Date: Thu, 10 Nov 2022 19:57:32 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog Message-ID: <20221110195732.1382314-1-wusamuel@google.com> Subject: [PATCH v1] Revert "cpufreq: schedutil: Move max CPU capacity to sugov_policy" From: Sam Wu To: "Rafael J. Wysocki" , Viresh Kumar , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , Lukasz Luba Cc: Sam Wu , Saravana Kannan , "Isaac J . Manjarres" , kernel-team@android.com, "Rafael J. Wysocki" , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org This reverts commit 6d5afdc97ea71958287364a1f1d07e59ef151b11. On a Pixel 6 device, it is observed that this commit increases latency by approximately 50ms, or 20%, in migrating a task that requires full CPU utilization from a LITTLE CPU to Fmax on a big CPU. Reverting this change restores the latency back to its original baseline value. Fixes: 6d5afdc97ea7 ("cpufreq: schedutil: Move max CPU capacity to sugov_policy") Cc: Lukasz Luba Cc: Saravana Kannan Cc: Isaac J. Manjarres Signed-off-by: Sam Wu --- kernel/sched/cpufreq_schedutil.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 9161d1136d01..1207c78f85c1 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -25,9 +25,6 @@ struct sugov_policy { unsigned int next_freq; unsigned int cached_raw_freq; - /* max CPU capacity, which is equal for all CPUs in freq. domain */ - unsigned long max; - /* The next fields are only needed if fast switch cannot be used: */ struct irq_work irq_work; struct kthread_work work; @@ -51,6 +48,7 @@ struct sugov_cpu { unsigned long util; unsigned long bw_dl; + unsigned long max; /* The field below is for single-CPU policies only: */ #ifdef CONFIG_NO_HZ_COMMON @@ -160,6 +158,7 @@ static void sugov_get_util(struct sugov_cpu *sg_cpu) { struct rq *rq = cpu_rq(sg_cpu->cpu); + sg_cpu->max = arch_scale_cpu_capacity(sg_cpu->cpu); sg_cpu->bw_dl = cpu_bw_dl(rq); sg_cpu->util = effective_cpu_util(sg_cpu->cpu, cpu_util_cfs(sg_cpu->cpu), FREQUENCY_UTIL, NULL); @@ -254,7 +253,6 @@ static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, */ static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time) { - struct sugov_policy *sg_policy = sg_cpu->sg_policy; unsigned long boost; /* No boost currently required */ @@ -282,8 +280,7 @@ static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time) * sg_cpu->util is already in capacity scale; convert iowait_boost * into the same scale so we can compare. */ - boost = sg_cpu->iowait_boost * sg_policy->max; - boost >>= SCHED_CAPACITY_SHIFT; + boost = (sg_cpu->iowait_boost * sg_cpu->max) >> SCHED_CAPACITY_SHIFT; boost = uclamp_rq_util_with(cpu_rq(sg_cpu->cpu), boost, NULL); if (sg_cpu->util < boost) sg_cpu->util = boost; @@ -340,7 +337,7 @@ static void sugov_update_single_freq(struct update_util_data *hook, u64 time, if (!sugov_update_single_common(sg_cpu, time, flags)) return; - next_f = get_next_freq(sg_policy, sg_cpu->util, sg_policy->max); + next_f = get_next_freq(sg_policy, sg_cpu->util, sg_cpu->max); /* * Do not reduce the frequency if the CPU has not been idle * recently, as the reduction is likely to be premature then. @@ -376,7 +373,6 @@ static void sugov_update_single_perf(struct update_util_data *hook, u64 time, unsigned int flags) { struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); - struct sugov_policy *sg_policy = sg_cpu->sg_policy; unsigned long prev_util = sg_cpu->util; /* @@ -403,8 +399,7 @@ static void sugov_update_single_perf(struct update_util_data *hook, u64 time, sg_cpu->util = prev_util; cpufreq_driver_adjust_perf(sg_cpu->cpu, map_util_perf(sg_cpu->bw_dl), - map_util_perf(sg_cpu->util), - sg_policy->max); + map_util_perf(sg_cpu->util), sg_cpu->max); sg_cpu->sg_policy->last_freq_update_time = time; } @@ -413,19 +408,25 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) { struct sugov_policy *sg_policy = sg_cpu->sg_policy; struct cpufreq_policy *policy = sg_policy->policy; - unsigned long util = 0; + unsigned long util = 0, max = 1; unsigned int j; for_each_cpu(j, policy->cpus) { struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j); + unsigned long j_util, j_max; sugov_get_util(j_sg_cpu); sugov_iowait_apply(j_sg_cpu, time); + j_util = j_sg_cpu->util; + j_max = j_sg_cpu->max; - util = max(j_sg_cpu->util, util); + if (j_util * max > j_max * util) { + util = j_util; + max = j_max; + } } - return get_next_freq(sg_policy, util, sg_policy->max); + return get_next_freq(sg_policy, util, max); } static void @@ -751,7 +752,7 @@ static int sugov_start(struct cpufreq_policy *policy) { struct sugov_policy *sg_policy = policy->governor_data; void (*uu)(struct update_util_data *data, u64 time, unsigned int flags); - unsigned int cpu = cpumask_first(policy->cpus); + unsigned int cpu; sg_policy->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC; sg_policy->last_freq_update_time = 0; @@ -759,7 +760,6 @@ static int sugov_start(struct cpufreq_policy *policy) sg_policy->work_in_progress = false; sg_policy->limits_changed = false; sg_policy->cached_raw_freq = 0; - sg_policy->max = arch_scale_cpu_capacity(cpu); sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS); -- 2.38.1.431.g37b22c650d-goog