From patchwork Wed Feb 1 14:36:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincent Guittot X-Patchwork-Id: 650849 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 56237C636D3 for ; Wed, 1 Feb 2023 14:36:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232401AbjBAOgi (ORCPT ); Wed, 1 Feb 2023 09:36:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231635AbjBAOgg (ORCPT ); Wed, 1 Feb 2023 09:36:36 -0500 Received: from mail-wm1-x332.google.com (mail-wm1-x332.google.com [IPv6:2a00:1450:4864:20::332]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D3CB48639 for ; Wed, 1 Feb 2023 06:36:35 -0800 (PST) Received: by mail-wm1-x332.google.com with SMTP id j32-20020a05600c1c2000b003dc4fd6e61dso1531826wms.5 for ; Wed, 01 Feb 2023 06:36:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=GVFffFUJyNe63P9deX/q/1x3JqOMjHMY9wDsGNLAhQY=; b=nQoLDhX2M8zRGalNQj4VJ9YYRnwMuT93/fFzauSFDXE8V5j21MFrqIsiXzY/Cd85rN aXpBoA3jsl0AdcdAEUsgsgnSc/G635Y3W56OfUWBm895mo12PbpkwPtjI+bIU0kOojIs 4lwTbqripg3IYy0r2o80nccIbYAC2JTt+xNHBDCbrbo6BBDRd7nG6jkkbNbNjpxrAjGp CbpSXyOKZQ/auwrNkK0Zl5IfRmTnwbPVdQSR3aNrm8QCmTDevm31aGcmYF+/OFRGO3PI 2XfrIwStxKDeZsmoG8CIxwy31o3pafq96rIxtXkjXcdpkWtppNEaM1UHeHwsFPu1jFTC EOEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=GVFffFUJyNe63P9deX/q/1x3JqOMjHMY9wDsGNLAhQY=; b=mtzYGEf2XMa5Okw2nwdUlTwF74zLeJUPtO6bWgSPtXKqD9lEcg0pCSGbLN3cTmggak 37/67o4aN30WAaWTrjP/CyHXVtORCXvZOcZ5zoFS9r46DU4KZwUVayu2woUyxuR84aCk ASbJGjjViYshGr+24h1LKYWy6ZqGCwev23+298oe1SwDqAdMQ1YiMkAkwn9s299W4sZc bIzVEhy2MlmqcgVZeme4t9biOP2xmahnivEyxhIrpFnmBDCj6k69MTgbpPP5XvcQencR Bhx3OfcK1YFXmI72SQwLPw/KoO5AiGxu3RClkzYx9KFdHKAiI+YSRoDsIePtDH3uMYQ2 8JkA== X-Gm-Message-State: AO0yUKVvmGsgglc2h86sl/LZBlYqY39xg24TDGKuQNGRYghF8dslklCz nwEM4xEDL5SbbcfGY+pZgpPzQg== X-Google-Smtp-Source: AK7set+9UhvEFpy1FP6pplbRh8OYMuoAMZQGyqF2kQXLig9KudE6eExy1JzXbEoTZm1NbCD15DBTtg== X-Received: by 2002:a05:600c:4f90:b0:3db:419:8d3b with SMTP id n16-20020a05600c4f9000b003db04198d3bmr2401314wmq.39.1675262193423; Wed, 01 Feb 2023 06:36:33 -0800 (PST) Received: from vingu-book.. ([2a01:e0a:f:6020:3db4:bf23:5fd8:a5]) by smtp.gmail.com with ESMTPSA id l19-20020a05600c2cd300b003cf71b1f66csm1846756wmc.0.2023.02.01.06.36.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Feb 2023 06:36:32 -0800 (PST) From: Vincent Guittot To: mingo@kernel.org, peterz@infradead.org, dietmar.eggemann@arm.com, qyousef@layalina.io, rafael@kernel.org, viresh.kumar@linaro.org, vschneid@redhat.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, kajetan.puchalski@arm.com Cc: lukasz.luba@arm.com, wvw@google.com, xuewen.yan94@gmail.com, han.lin@mediatek.com, Jonathan.JMChen@mediatek.com, Vincent Guittot Subject: [PATCH 1/2 v5] sched/fair: unlink misfit task from cpu overutilized Date: Wed, 1 Feb 2023 15:36:27 +0100 Message-Id: <20230201143628.270912-2-vincent.guittot@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230201143628.270912-1-vincent.guittot@linaro.org> References: <20230201143628.270912-1-vincent.guittot@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org By taking into account uclamp_min, the 1:1 relation between task misfit and cpu overutilized is no more true as a task with a small util_avg may not fit a high capacity cpu because of uclamp_min constraint. Add a new state in util_fits_cpu() to reflect the case that task would fit a CPU except for the uclamp_min hint which is a performance requirement. Use -1 to reflect that a CPU doesn't fit only because of uclamp_min so we can use this new value to take additional action to select the best CPU that doesn't match uclamp_min hint. When util_fits_cpu() returns -1, we will continue to look for a possible CPU with better performance, which replaces Capacity Inversion detection with capacity_orig_of() - thermal_load_avg to detect a capacity inversion. Signed-off-by: Vincent Guittot Tested-by: Kajetan Puchalski Reviewed-and-tested-by: Qais Yousef Reviewed-by: Dietmar Eggemann --- Change since v4: - Add more details in commit message - Fix typo - Add Tag kernel/sched/fair.c | 105 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 82 insertions(+), 23 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 7c46485d65d7..074742f107c0 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4561,8 +4561,8 @@ static inline int util_fits_cpu(unsigned long util, * handle the case uclamp_min > uclamp_max. */ uclamp_min = min(uclamp_min, uclamp_max); - if (util < uclamp_min && capacity_orig != SCHED_CAPACITY_SCALE) - fits = fits && (uclamp_min <= capacity_orig_thermal); + if (fits && (util < uclamp_min) && (uclamp_min > capacity_orig_thermal)) + return -1; return fits; } @@ -4572,7 +4572,11 @@ static inline int task_fits_cpu(struct task_struct *p, int cpu) unsigned long uclamp_min = uclamp_eff_value(p, UCLAMP_MIN); unsigned long uclamp_max = uclamp_eff_value(p, UCLAMP_MAX); unsigned long util = task_util_est(p); - return util_fits_cpu(util, uclamp_min, uclamp_max, cpu); + /* + * Return true only if the cpu fully fits the task requirements, which + * include the utilization but also the performance hints. + */ + return (util_fits_cpu(util, uclamp_min, uclamp_max, cpu) > 0); } static inline void update_misfit_status(struct task_struct *p, struct rq *rq) @@ -6138,6 +6142,7 @@ static inline bool cpu_overutilized(int cpu) unsigned long rq_util_min = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MIN); unsigned long rq_util_max = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MAX); + /* Return true only if the utilization doesn't fit CPU's capacity */ return !util_fits_cpu(cpu_util_cfs(cpu), rq_util_min, rq_util_max, cpu); } @@ -6931,6 +6936,7 @@ static int select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target) { unsigned long task_util, util_min, util_max, best_cap = 0; + int fits, best_fits = 0; int cpu, best_cpu = -1; struct cpumask *cpus; @@ -6946,12 +6952,28 @@ select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target) if (!available_idle_cpu(cpu) && !sched_idle_cpu(cpu)) continue; - if (util_fits_cpu(task_util, util_min, util_max, cpu)) + + fits = util_fits_cpu(task_util, util_min, util_max, cpu); + + /* This CPU fits with all requirements */ + if (fits > 0) return cpu; + /* + * Only the min performance hint (i.e. uclamp_min) doesn't fit. + * Look for the CPU with best capacity. + */ + else if (fits < 0) + cpu_cap = capacity_orig_of(cpu) - thermal_load_avg(cpu_rq(cpu)); - if (cpu_cap > best_cap) { + /* + * First, select CPU which fits better (-1 being better than 0). + * Then, select the one with best capacity at same level. + */ + if ((fits < best_fits) || + ((fits == best_fits) && (cpu_cap > best_cap))) { best_cap = cpu_cap; best_cpu = cpu; + best_fits = fits; } } @@ -6964,7 +6986,11 @@ static inline bool asym_fits_cpu(unsigned long util, int cpu) { if (sched_asym_cpucap_active()) - return util_fits_cpu(util, util_min, util_max, cpu); + /* + * Return true only if the cpu fully fits the task requirements + * which include the utilization and the performance hints. + */ + return (util_fits_cpu(util, util_min, util_max, cpu) > 0); return true; } @@ -7331,6 +7357,9 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) unsigned long p_util_max = uclamp_is_used() ? uclamp_eff_value(p, UCLAMP_MAX) : 1024; struct root_domain *rd = this_rq()->rd; int cpu, best_energy_cpu, target = -1; + int prev_fits = -1, best_fits = -1; + unsigned long best_thermal_cap = 0; + unsigned long prev_thermal_cap = 0; struct sched_domain *sd; struct perf_domain *pd; struct energy_env eenv; @@ -7366,6 +7395,7 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) unsigned long prev_spare_cap = 0; int max_spare_cap_cpu = -1; unsigned long base_energy; + int fits, max_fits = -1; cpumask_and(cpus, perf_domain_span(pd), cpu_online_mask); @@ -7415,7 +7445,9 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) util_min = max(rq_util_min, p_util_min); util_max = max(rq_util_max, p_util_max); } - if (!util_fits_cpu(util, util_min, util_max, cpu)) + + fits = util_fits_cpu(util, util_min, util_max, cpu); + if (!fits) continue; lsub_positive(&cpu_cap, util); @@ -7423,7 +7455,9 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) if (cpu == prev_cpu) { /* Always use prev_cpu as a candidate. */ prev_spare_cap = cpu_cap; - } else if (cpu_cap > max_spare_cap) { + prev_fits = fits; + } else if ((fits > max_fits) || + ((fits == max_fits) && (cpu_cap > max_spare_cap))) { /* * Find the CPU with the maximum spare capacity * among the remaining CPUs in the performance @@ -7431,6 +7465,7 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) */ max_spare_cap = cpu_cap; max_spare_cap_cpu = cpu; + max_fits = fits; } } @@ -7449,26 +7484,50 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) if (prev_delta < base_energy) goto unlock; prev_delta -= base_energy; + prev_thermal_cap = cpu_thermal_cap; best_delta = min(best_delta, prev_delta); } /* Evaluate the energy impact of using max_spare_cap_cpu. */ if (max_spare_cap_cpu >= 0 && max_spare_cap > prev_spare_cap) { + /* Current best energy cpu fits better */ + if (max_fits < best_fits) + continue; + + /* + * Both don't fit performance hint (i.e. uclamp_min) + * but best energy cpu has better capacity. + */ + if ((max_fits < 0) && + (cpu_thermal_cap <= best_thermal_cap)) + continue; + cur_delta = compute_energy(&eenv, pd, cpus, p, max_spare_cap_cpu); /* CPU utilization has changed */ if (cur_delta < base_energy) goto unlock; cur_delta -= base_energy; - if (cur_delta < best_delta) { - best_delta = cur_delta; - best_energy_cpu = max_spare_cap_cpu; - } + + /* + * Both fit for the task but best energy cpu has lower + * energy impact. + */ + if ((max_fits > 0) && (best_fits > 0) && + (cur_delta >= best_delta)) + continue; + + best_delta = cur_delta; + best_energy_cpu = max_spare_cap_cpu; + best_fits = max_fits; + best_thermal_cap = cpu_thermal_cap; } } rcu_read_unlock(); - if (best_delta < prev_delta) + if ((best_fits > prev_fits) || + ((best_fits > 0) && (best_delta < prev_delta)) || + ((best_fits < 0) && (best_thermal_cap > prev_thermal_cap))) target = best_energy_cpu; return target; @@ -10271,24 +10330,23 @@ static struct sched_group *find_busiest_group(struct lb_env *env) */ update_sd_lb_stats(env, &sds); - if (sched_energy_enabled()) { - struct root_domain *rd = env->dst_rq->rd; - - if (rcu_dereference(rd->pd) && !READ_ONCE(rd->overutilized)) - goto out_balanced; - } - - local = &sds.local_stat; - busiest = &sds.busiest_stat; - /* There is no busy sibling group to pull tasks from */ if (!sds.busiest) goto out_balanced; + busiest = &sds.busiest_stat; + /* Misfit tasks should be dealt with regardless of the avg load */ if (busiest->group_type == group_misfit_task) goto force_balance; + if (sched_energy_enabled()) { + struct root_domain *rd = env->dst_rq->rd; + + if (rcu_dereference(rd->pd) && !READ_ONCE(rd->overutilized)) + goto out_balanced; + } + /* ASYM feature bypasses nice load balance check */ if (busiest->group_type == group_asym_packing) goto force_balance; @@ -10301,6 +10359,7 @@ static struct sched_group *find_busiest_group(struct lb_env *env) if (busiest->group_type == group_imbalanced) goto force_balance; + local = &sds.local_stat; /* * If the local group is busier than the selected busiest group * don't try and pull any tasks.