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 839F8C433EF for ; Wed, 12 Jan 2022 16:16:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355070AbiALQPy (ORCPT ); Wed, 12 Jan 2022 11:15:54 -0500 Received: from foss.arm.com ([217.140.110.172]:32980 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355047AbiALQOu (ORCPT ); Wed, 12 Jan 2022 11:14:50 -0500 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 235961FB; Wed, 12 Jan 2022 08:14:50 -0800 (PST) Received: from localhost.localdomain (unknown [10.57.10.212]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A160F3F774; Wed, 12 Jan 2022 08:14:48 -0800 (PST) From: Vincent Donnefort To: peterz@infradead.org, mingo@redhat.com, vincent.guittot@linaro.org Cc: linux-kernel@vger.kernel.org, dietmar.eggemann@arm.com, valentin.schneider@arm.com, morten.rasmussen@arm.com, chris.redpath@arm.com, qperret@google.com, lukasz.luba@arm.com Subject: [PATCH v2 3/7] sched, drivers: Remove max param from effective_cpu_util()/sched_cpu_util() Date: Wed, 12 Jan 2022 16:12:26 +0000 Message-Id: <20220112161230.836326-4-vincent.donnefort@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220112161230.836326-1-vincent.donnefort@arm.com> References: <20220112161230.836326-1-vincent.donnefort@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dietmar Eggemann effective_cpu_util() already has a `int cpu' parameter which allows to retrieve the CPU capacity scale factor (or maximum CPU capacity) inside this function via an arch_scale_cpu_capacity(cpu). A lot of code calling effective_cpu_util() (or the shim sched_cpu_util()) needs the maximum CPU capacity, i.e. it will call arch_scale_cpu_capacity() already. But not having to pass it into effective_cpu_util() will make the EAS wake-up code easier, especially when the maximum CPU capacity reduced by the thermal pressure is passed through the EAS wake-up functions. Due to the asymmetric CPU capacity support of arm/arm64 architectures, arch_scale_cpu_capacity(int cpu) is a per-CPU variable read access via per_cpu(cpu_scale, cpu) on such a system. On all other architectures it is a a compile-time constant (SCHED_CAPACITY_SCALE). Signed-off-by: Dietmar Eggemann diff --git a/drivers/powercap/dtpm_cpu.c b/drivers/powercap/dtpm_cpu.c index b740866b228d..0d57bcf83ae5 100644 --- a/drivers/powercap/dtpm_cpu.c +++ b/drivers/powercap/dtpm_cpu.c @@ -70,34 +70,19 @@ static u64 set_pd_power_limit(struct dtpm *dtpm, u64 power_limit) static u64 scale_pd_power_uw(struct cpumask *pd_mask, u64 power) { - unsigned long max = 0, sum_util = 0; + unsigned long max, sum_util = 0; int cpu; - for_each_cpu_and(cpu, pd_mask, cpu_online_mask) { - - /* - * The capacity is the same for all CPUs belonging to - * the same perf domain, so a single call to - * arch_scale_cpu_capacity() is enough. However, we - * need the CPU parameter to be initialized by the - * loop, so the call ends up in this block. - * - * We can initialize 'max' with a cpumask_first() call - * before the loop but the bits computation is not - * worth given the arch_scale_cpu_capacity() just - * returns a value where the resulting assembly code - * will be optimized by the compiler. - */ - max = arch_scale_cpu_capacity(cpu); - sum_util += sched_cpu_util(cpu, max); - } - /* - * In the improbable case where all the CPUs of the perf - * domain are offline, 'max' will be zero and will lead to an - * illegal operation with a zero division. + * The capacity is the same for all CPUs belonging to + * the same perf domain. */ - return max ? (power * ((sum_util << 10) / max)) >> 10 : 0; + max = arch_scale_cpu_capacity(cpumask_first(pd_mask)); + + for_each_cpu_and(cpu, pd_mask, cpu_online_mask) + sum_util += sched_cpu_util(cpu); + + return (power * ((sum_util << 10) / max)) >> 10; } static u64 get_pd_power_uw(struct dtpm *dtpm) diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c index 43b1ae8a7789..f499f3c0e633 100644 --- a/drivers/thermal/cpufreq_cooling.c +++ b/drivers/thermal/cpufreq_cooling.c @@ -137,11 +137,9 @@ static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev, static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu, int cpu_idx) { - unsigned long max = arch_scale_cpu_capacity(cpu); - unsigned long util; + unsigned long util = sched_cpu_util(cpu); - util = sched_cpu_util(cpu, max); - return (util * 100) / max; + return (util * 100) / arch_scale_cpu_capacity(cpu); } #else /* !CONFIG_SMP */ static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu, diff --git a/include/linux/sched.h b/include/linux/sched.h index d2e261adb8ea..d9e672ab71f8 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2176,7 +2176,7 @@ extern long sched_getaffinity(pid_t pid, struct cpumask *mask); #ifdef CONFIG_SMP /* Returns effective CPU energy utilization, as seen by the scheduler */ -unsigned long sched_cpu_util(int cpu, unsigned long max); +unsigned long sched_cpu_util(int cpu); #endif /* CONFIG_SMP */ #ifdef CONFIG_RSEQ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 11c6aeef4583..668ffae1888e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7086,12 +7086,14 @@ struct task_struct *idle_task(int cpu) * required to meet deadlines. */ unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, - unsigned long max, enum cpu_util_type type, + enum cpu_util_type type, struct task_struct *p) { - unsigned long dl_util, util, irq; + unsigned long dl_util, util, irq, max; struct rq *rq = cpu_rq(cpu); + max = arch_scale_cpu_capacity(cpu); + if (!uclamp_is_used() && type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt)) { return max; @@ -7171,10 +7173,9 @@ unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, return min(max, util); } -unsigned long sched_cpu_util(int cpu, unsigned long max) +unsigned long sched_cpu_util(int cpu) { - return effective_cpu_util(cpu, cpu_util_cfs(cpu), max, - ENERGY_UTIL, NULL); + return effective_cpu_util(cpu, cpu_util_cfs(cpu), ENERGY_UTIL, NULL); } #endif /* CONFIG_SMP */ diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 26778884d9ab..9b88fc8c6ea8 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -164,11 +164,10 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, static void sugov_get_util(struct sugov_cpu *sg_cpu) { struct rq *rq = cpu_rq(sg_cpu->cpu); - unsigned long max = arch_scale_cpu_capacity(sg_cpu->cpu); - sg_cpu->max = max; + 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), max, + sg_cpu->util = effective_cpu_util(sg_cpu->cpu, cpu_util_cfs(sg_cpu->cpu), FREQUENCY_UTIL, NULL); } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 046d5397eb8a..4fc63deda620 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6558,12 +6558,11 @@ static long 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 = cpu_cap; + unsigned long max_util = 0, sum_util = 0, cpu_cap; int cpu; - _cpu_cap -= arch_scale_thermal_pressure(cpumask_first(pd_mask)); + cpu_cap = arch_scale_cpu_capacity(cpumask_first(pd_mask)); + cpu_cap -= arch_scale_thermal_pressure(cpumask_first(pd_mask)); /* * The capacity state of CPUs of the current rd can be driven by CPUs @@ -6600,10 +6599,10 @@ 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. */ - cpu_util = effective_cpu_util(cpu, util_running, cpu_cap, - ENERGY_UTIL, NULL); + cpu_util = effective_cpu_util(cpu, util_running, ENERGY_UTIL, + NULL); - sum_util += min(cpu_util, _cpu_cap); + sum_util += min(cpu_util, cpu_cap); /* * Performance domain frequency: utilization clamping @@ -6612,12 +6611,12 @@ compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd) * NOTE: in case RT tasks are running, by default the * FREQUENCY_UTIL's utilization can be max OPP. */ - cpu_util = effective_cpu_util(cpu, util_freq, cpu_cap, - FREQUENCY_UTIL, tsk); - max_util = max(max_util, min(cpu_util, _cpu_cap)); + cpu_util = effective_cpu_util(cpu, util_freq, FREQUENCY_UTIL, + tsk); + max_util = max(max_util, min(cpu_util, cpu_cap)); } - return em_cpu_energy(pd->em_pd, max_util, sum_util, _cpu_cap); + return em_cpu_energy(pd->em_pd, max_util, sum_util, cpu_cap); } /* diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index fdf2a9e54c0e..135c37358dc0 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2997,7 +2997,7 @@ enum cpu_util_type { }; unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, - unsigned long max, enum cpu_util_type type, + enum cpu_util_type type, struct task_struct *p); static inline unsigned long cpu_bw_dl(struct rq *rq) -- 2.25.1