From patchwork Thu Jun 10 15:03:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Luba X-Patchwork-Id: 458839 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7B3AC47094 for ; Thu, 10 Jun 2021 15:03:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C932B613E9 for ; Thu, 10 Jun 2021 15:03:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231534AbhFJPFh (ORCPT ); Thu, 10 Jun 2021 11:05:37 -0400 Received: from foss.arm.com ([217.140.110.172]:33974 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230410AbhFJPFg (ORCPT ); Thu, 10 Jun 2021 11:05:36 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4077C1396; Thu, 10 Jun 2021 08:03:40 -0700 (PDT) Received: from e123648.arm.com (unknown [10.57.4.220]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 87FBB3F719; Thu, 10 Jun 2021 08:03:36 -0700 (PDT) From: Lukasz Luba To: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org, peterz@infradead.org, rjw@rjwysocki.net, viresh.kumar@linaro.org, vincent.guittot@linaro.org, qperret@google.com, dietmar.eggemann@arm.com, vincent.donnefort@arm.com, lukasz.luba@arm.com, Beata.Michalska@arm.com, mingo@redhat.com, juri.lelli@redhat.com, rostedt@goodmis.org, segall@google.com, mgorman@suse.de, bristot@redhat.com, thara.gopinath@linaro.org, amit.kachhap@gmail.com, amitk@kernel.org, rui.zhang@intel.com, daniel.lezcano@linaro.org Subject: [PATCH v3 1/3] thermal: cpufreq_cooling: Update also offline CPUs per-cpu thermal_pressure Date: Thu, 10 Jun 2021 16:03:22 +0100 Message-Id: <20210610150324.22919-2-lukasz.luba@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210610150324.22919-1-lukasz.luba@arm.com> References: <20210610150324.22919-1-lukasz.luba@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The thermal pressure signal gives information to the scheduler about reduced CPU capacity due to thermal. It is based on a value stored in a per-cpu 'thermal_pressure' variable. The online CPUs will get the new value there, while the offline won't. Unfortunately, when the CPU is back online, the value read from per-cpu variable might be wrong (stale data). This might affect the scheduler decisions, since it sees the CPU capacity differently than what is actually available. Fix it by making sure that all online+offline CPUs would get the proper value in their per-cpu variable when thermal framework sets capping. Fixes: f12e4f66ab6a3 ("thermal/cpu-cooling: Update thermal pressure in case of a maximum frequency capping") Signed-off-by: Lukasz Luba Acked-by: Viresh Kumar --- drivers/thermal/cpufreq_cooling.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c index eeb4e4b76c0b..43b1ae8a7789 100644 --- a/drivers/thermal/cpufreq_cooling.c +++ b/drivers/thermal/cpufreq_cooling.c @@ -478,7 +478,7 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, ret = freq_qos_update_request(&cpufreq_cdev->qos_req, frequency); if (ret >= 0) { cpufreq_cdev->cpufreq_state = state; - cpus = cpufreq_cdev->policy->cpus; + cpus = cpufreq_cdev->policy->related_cpus; max_capacity = arch_scale_cpu_capacity(cpumask_first(cpus)); capacity = frequency * max_capacity; capacity /= cpufreq_cdev->policy->cpuinfo.max_freq; From patchwork Thu Jun 10 15:03:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Luba X-Patchwork-Id: 458163 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DF1FC48BD1 for ; Thu, 10 Jun 2021 15:03:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60C94613FF for ; Thu, 10 Jun 2021 15:03:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231553AbhFJPFl (ORCPT ); Thu, 10 Jun 2021 11:05:41 -0400 Received: from foss.arm.com ([217.140.110.172]:34002 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231551AbhFJPFk (ORCPT ); Thu, 10 Jun 2021 11:05:40 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 437FD13A1; Thu, 10 Jun 2021 08:03:44 -0700 (PDT) Received: from e123648.arm.com (unknown [10.57.4.220]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 8CD2E3F719; Thu, 10 Jun 2021 08:03:40 -0700 (PDT) From: Lukasz Luba To: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org, peterz@infradead.org, rjw@rjwysocki.net, viresh.kumar@linaro.org, vincent.guittot@linaro.org, qperret@google.com, dietmar.eggemann@arm.com, vincent.donnefort@arm.com, lukasz.luba@arm.com, Beata.Michalska@arm.com, mingo@redhat.com, juri.lelli@redhat.com, rostedt@goodmis.org, segall@google.com, mgorman@suse.de, bristot@redhat.com, thara.gopinath@linaro.org, amit.kachhap@gmail.com, amitk@kernel.org, rui.zhang@intel.com, daniel.lezcano@linaro.org Subject: [PATCH v3 2/3] sched/fair: Take thermal pressure into account while estimating energy Date: Thu, 10 Jun 2021 16:03:23 +0100 Message-Id: <20210610150324.22919-3-lukasz.luba@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210610150324.22919-1-lukasz.luba@arm.com> References: <20210610150324.22919-1-lukasz.luba@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Energy Aware Scheduling (EAS) needs to be able to predict the frequency requests made by the SchedUtil governor to properly estimate energy used in the future. It has to take into account CPUs utilization and forecast Performance Domain (PD) frequency. There is a corner case when the max allowed frequency might be reduced due to thermal. SchedUtil is aware of that reduced frequency, so it should be taken into account also in EAS estimations. SchedUtil, as a CPUFreq governor, knows the maximum allowed frequency of a CPU, thanks to cpufreq_driver_resolve_freq() and internal clamping to 'policy::max'. SchedUtil is responsible to respect that upper limit while setting the frequency through CPUFreq drivers. This effective frequency is stored internally in 'sugov_policy::next_freq' and EAS has to predict that value. In the existing code the raw value of arch_scale_cpu_capacity() is used for clamping the returned CPU utilization from effective_cpu_util(). This patch fixes issue with too big single CPU utilization, by introducing clamping to the allowed CPU capacity. The allowed CPU capacity is a CPU capacity reduced by thermal pressure signal. We rely on this load avg geometric series in similar way as other mechanisms in the scheduler. Thanks to knowledge about allowed CPU capacity, we don't get too big value for a single CPU utilization, which is then added to the util sum. The util sum is used as a source of information for estimating whole PD energy. To avoid wrong energy estimation in EAS (due to capped frequency), make sure that the calculation of util sum is aware of allowed CPU capacity. This thermal pressure might be visible in scenarios where the CPUs are not heavily loaded, but some other component (like GPU) drastically reduced available power budget and increased the SoC temperature. Thus, we still use EAS for task placement and CPUs are not over-utilized. Signed-off-by: Lukasz Luba Reviewed-by: Vincent Guittot --- kernel/sched/fair.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 161b92aa1c79..237726217dad 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6527,8 +6527,12 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd) struct cpumask *pd_mask = perf_domain_span(pd); unsigned long cpu_cap = arch_scale_cpu_capacity(cpumask_first(pd_mask)); unsigned long max_util = 0, sum_util = 0; + unsigned long _cpu_cap, thermal_pressure; int cpu; + thermal_pressure = arch_scale_thermal_pressure(cpumask_first(pd_mask)); + _cpu_cap = cpu_cap - thermal_pressure; + /* * The capacity state of CPUs of the current rd can be driven by CPUs * of another rd if they belong to the same pd. So, account for the @@ -6564,8 +6568,10 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd) * is already enough to scale the EM reported power * consumption at the (eventually clamped) cpu_capacity. */ - sum_util += effective_cpu_util(cpu, util_running, cpu_cap, - ENERGY_UTIL, NULL); + cpu_util = effective_cpu_util(cpu, util_running, cpu_cap, + ENERGY_UTIL, NULL); + + sum_util += min(cpu_util, _cpu_cap); /* * Performance domain frequency: utilization clamping @@ -6576,7 +6582,7 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd) */ cpu_util = effective_cpu_util(cpu, util_freq, cpu_cap, FREQUENCY_UTIL, tsk); - max_util = max(max_util, cpu_util); + max_util = max(max_util, min(cpu_util, _cpu_cap)); } return em_cpu_energy(pd->em_pd, max_util, sum_util); From patchwork Thu Jun 10 15:03:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Luba X-Patchwork-Id: 458838 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01A32C47094 for ; Thu, 10 Jun 2021 15:03:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE0A3613DD for ; Thu, 10 Jun 2021 15:03:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231564AbhFJPFq (ORCPT ); Thu, 10 Jun 2021 11:05:46 -0400 Received: from foss.arm.com ([217.140.110.172]:34028 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231549AbhFJPFo (ORCPT ); Thu, 10 Jun 2021 11:05:44 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 433E913D5; Thu, 10 Jun 2021 08:03:48 -0700 (PDT) Received: from e123648.arm.com (unknown [10.57.4.220]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 8ED4D3F719; Thu, 10 Jun 2021 08:03:44 -0700 (PDT) From: Lukasz Luba To: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org, peterz@infradead.org, rjw@rjwysocki.net, viresh.kumar@linaro.org, vincent.guittot@linaro.org, qperret@google.com, dietmar.eggemann@arm.com, vincent.donnefort@arm.com, lukasz.luba@arm.com, Beata.Michalska@arm.com, mingo@redhat.com, juri.lelli@redhat.com, rostedt@goodmis.org, segall@google.com, mgorman@suse.de, bristot@redhat.com, thara.gopinath@linaro.org, amit.kachhap@gmail.com, amitk@kernel.org, rui.zhang@intel.com, daniel.lezcano@linaro.org Subject: [PATCH v3 3/3] sched/cpufreq: Consider reduced CPU capacity in energy calculation Date: Thu, 10 Jun 2021 16:03:24 +0100 Message-Id: <20210610150324.22919-4-lukasz.luba@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210610150324.22919-1-lukasz.luba@arm.com> References: <20210610150324.22919-1-lukasz.luba@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Energy Aware Scheduling (EAS) needs to predict the decisions made by SchedUtil. The map_util_freq() exists to do that. There are corner cases where the max allowed frequency might be reduced (due to thermal). SchedUtil as a CPUFreq governor, is aware of that but EAS is not. This patch aims to address it. SchedUtil stores the maximum allowed frequency in 'sugov_policy::next_freq' field. EAS has to predict that value, which is the real used frequency. That value is made after a call to cpufreq_driver_resolve_freq() which clamps to the CPUFreq policy limits. In the existing code EAS is not able to predict that real frequency. This leads to energy estimation errors. To avoid wrong energy estimation in EAS (due to frequency miss prediction) make sure that the step which calculates Performance Domain frequency, is also aware of the allowed CPU capacity. Furthermore, modify map_util_freq() to not extend the frequency value. Instead, use map_util_perf() to extend the util value in both places: SchedUtil and EAS, but for EAS clamp it to max allowed CPU capacity. In the end, we achieve the same desirable behavior for both subsystems and alignment in regards to the real CPU frequency. Acked-by: Rafael J. Wysocki (For the schedutil part) Signed-off-by: Lukasz Luba --- include/linux/energy_model.h | 16 +++++++++++++--- include/linux/sched/cpufreq.h | 2 +- kernel/sched/cpufreq_schedutil.c | 1 + kernel/sched/fair.c | 2 +- 4 files changed, 16 insertions(+), 5 deletions(-) diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index 757fc60658fa..3f221dbf5f95 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -91,6 +91,8 @@ void em_dev_unregister_perf_domain(struct device *dev); * @pd : performance domain for which energy has to be estimated * @max_util : highest utilization among CPUs of the domain * @sum_util : sum of the utilization of all CPUs in the domain + * @allowed_cpu_cap : maximum allowed CPU capacity for the @pd, which + might reflect reduced frequency (due to thermal) * * This function must be used only for CPU devices. There is no validation, * i.e. if the EM is a CPU type and has cpumask allocated. It is called from @@ -100,7 +102,8 @@ void em_dev_unregister_perf_domain(struct device *dev); * a capacity state satisfying the max utilization of the domain. */ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, - unsigned long max_util, unsigned long sum_util) + unsigned long max_util, unsigned long sum_util, + unsigned long allowed_cpu_cap) { unsigned long freq, scale_cpu; struct em_perf_state *ps; @@ -112,11 +115,17 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, /* * In order to predict the performance state, map the utilization of * the most utilized CPU of the performance domain to a requested - * frequency, like schedutil. + * frequency, like schedutil. Take also into account that the real + * frequency might be set lower (due to thermal capping). Thus, clamp + * max utilization to the allowed CPU capacity before calculating + * effective frequency. */ cpu = cpumask_first(to_cpumask(pd->cpus)); scale_cpu = arch_scale_cpu_capacity(cpu); ps = &pd->table[pd->nr_perf_states - 1]; + + max_util = map_util_perf(max_util); + max_util = min(max_util, allowed_cpu_cap); freq = map_util_freq(max_util, ps->frequency, scale_cpu); /* @@ -209,7 +218,8 @@ static inline struct em_perf_domain *em_pd_get(struct device *dev) return NULL; } static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, - unsigned long max_util, unsigned long sum_util) + unsigned long max_util, unsigned long sum_util, + unsigned long allowed_cpu_cap) { return 0; } diff --git a/include/linux/sched/cpufreq.h b/include/linux/sched/cpufreq.h index 6205578ab6ee..bdd31ab93bc5 100644 --- a/include/linux/sched/cpufreq.h +++ b/include/linux/sched/cpufreq.h @@ -26,7 +26,7 @@ bool cpufreq_this_cpu_can_update(struct cpufreq_policy *policy); static inline unsigned long map_util_freq(unsigned long util, unsigned long freq, unsigned long cap) { - return (freq + (freq >> 2)) * util / cap; + return freq * util / cap; } static inline unsigned long map_util_perf(unsigned long util) diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 4f09afd2f321..57124614363d 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -151,6 +151,7 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, unsigned int freq = arch_scale_freq_invariant() ? policy->cpuinfo.max_freq : policy->cur; + util = map_util_perf(util); freq = map_util_freq(util, freq, max); if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 237726217dad..3795b96a149b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6585,7 +6585,7 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd) max_util = max(max_util, min(cpu_util, _cpu_cap)); } - return em_cpu_energy(pd->em_pd, max_util, sum_util); + return em_cpu_energy(pd->em_pd, max_util, sum_util, _cpu_cap); } /*