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[209.132.180.67]) by mx.google.com with ESMTP id r4si8090621edm.100.2019.11.16.05.16.27; Sat, 16 Nov 2019 05:16:27 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-pm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=GirAD+vK; spf=pass (google.com: best guess record for domain of linux-pm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-pm-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727517AbfKPNQX (ORCPT + 10 others); Sat, 16 Nov 2019 08:16:23 -0500 Received: from mail-wr1-f67.google.com ([209.85.221.67]:39948 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727437AbfKPNQX (ORCPT ); Sat, 16 Nov 2019 08:16:23 -0500 Received: by mail-wr1-f67.google.com with SMTP id q15so1121144wrw.7 for ; Sat, 16 Nov 2019 05:16:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=tg11cTivSk8CuEqGhmHmDNWvHOysA3jwYAGlqgKbG4c=; b=GirAD+vKxjyd5OFXVVcD73825caTPpQT3zyFYDhPJmQP2+wOrhtIH3Doi0c7zREGmj p1x6DfxjpOLX2Ec/MslH8bQpMTPbvFPrhqstclENzGsx0jJYmeY5UEyKA6dHgIiY//JO qaPC2I+05TfMDm+138SK6j7be0b1aPpocydbxi9HCLMjnzIn4mMkLZM9ZnCFo5suca69 ACNkNHfQ9WqlB2ALMDyfuZxiVeCeo59RziqRDnhbm2dRmRDJz0+puD1RaeHpMVQqaa7I 8jXOn8UpiFOcHYJF2dF+w3bE/PCL00vm7vWt1xjNkRbUrosteggtbrGXWf3hxv8RpxPS cI2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=tg11cTivSk8CuEqGhmHmDNWvHOysA3jwYAGlqgKbG4c=; b=R1K6SXDb5GZXlGwB9RsGDEKrrD+UPIRW+zNsqtQ9R5z4bKtaaf0bRSt5TKhbiNuo75 NKATATIvo7JdOfSnmXJy7aNHVb9juFcfDc5/EzQOcUicMJSM6jgq6s3Yoi7nwduFVKoJ kRCxvXIni+MR/9QaFHrNr2gx1liMxwa4frXKiJausEV4+cOnAGvDkLAz+ePUqytFrrcL r3HiHv9q/WyYL7JAuO06/7SfZ0h05QQroU64BuJBgY8XJ/DGk8YS7/qVlEvX0VgfHnuu JheVXvPPN5vLpNecVQRrV3cDh2tVH/Gx3/DvBFH1Jn6aTpBWDzWXsee585r3XUOZWlsr B5cw== X-Gm-Message-State: APjAAAU7bgeJvbr8br0k2+eyKrZRW8jCpmWIoqo83hANBBAFmOwtSCvk R74sRfb+WuehmYRpZ9hSB2Avyg== X-Received: by 2002:a05:6000:110a:: with SMTP id z10mr19691490wrw.291.1573910180022; Sat, 16 Nov 2019 05:16:20 -0800 (PST) Received: from localhost.localdomain ([2a01:e34:ed2f:f020:b462:d85e:9aab:bc1d]) by smtp.gmail.com with ESMTPSA id r2sm11128914wma.44.2019.11.16.05.16.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 16 Nov 2019 05:16:19 -0800 (PST) From: Daniel Lezcano To: rafael@kernel.org Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, ulf.hansson@linaro.org Subject: [PATCH V2 1/2] cpuidle: Replace use_deepest_state flag by forced_idle_latency_limit_ns Date: Sat, 16 Nov 2019 14:16:12 +0100 Message-Id: <20191116131613.15733-1-daniel.lezcano@linaro.org> X-Mailer: git-send-email 2.17.1 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org We want to specify a latency constraint when choosing an idle state at play_idle time. Instead of duplicating the information in the structure or propagate the latency in the call stack, change the use_deepest_state by forced_latency_limit_ns to introduce this constraint. The idea being that when it is set, idle is forced (i.e. no governors), but there is a latency limit for the state to use. A zero latency constraint means "do not use the deepest idle state path" as the 'use_deepest_state' boolean was used in the cpuidle_idle_call. In addition add the play_idle_precise() function getting a nanosec base latency constraint as parameter. The play_idle() function becomes a wrapper passing an U64_MAX to play_idle_precise(). Suggested-by: Rafael J. Wysocki Signed-off-by: Daniel Lezcano --- drivers/cpuidle/cpuidle.c | 10 +++++----- include/linux/cpu.h | 6 +++++- include/linux/cpuidle.h | 6 +++--- kernel/sched/idle.c | 14 +++++++------- 4 files changed, 20 insertions(+), 16 deletions(-) -- 2.17.1 diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 44ae39f2b47a..62226fadc02d 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -100,19 +100,19 @@ static int find_deepest_state(struct cpuidle_driver *drv, /** * cpuidle_use_deepest_state - Set/clear governor override flag. - * @enable: New value of the flag. + * @latency_limit_ns: A latency limit constraint * - * Set/unset the current CPU to use the deepest idle state (override governors - * going forward if set). + * Set/unset the current CPU to use the deepest idle state with the exit + * latency within @latency_limit_ns */ -void cpuidle_use_deepest_state(bool enable) +void cpuidle_use_deepest_state(u64 latency_limit_ns) { struct cpuidle_device *dev; preempt_disable(); dev = cpuidle_get_device(); if (dev) - dev->use_deepest_state = enable; + dev->forced_idle_latency_limit_ns = latency_limit_ns; preempt_enable(); } diff --git a/include/linux/cpu.h b/include/linux/cpu.h index d0633ebdaa9c..4c9694e209a5 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -179,7 +179,11 @@ void arch_cpu_idle_dead(void); int cpu_report_state(int cpu); int cpu_check_up_prepare(int cpu); void cpu_set_state_online(int cpu); -void play_idle(unsigned long duration_us); +void play_idle_precise(u64 duration_ns, u64 latency_ns); +static inline void play_idle(unsigned long duration_us) +{ + play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX); +} #ifdef CONFIG_HOTPLUG_CPU bool cpu_wait_death(unsigned int cpu, int seconds); diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index d23a3b1ddcf6..1f3f4dd01e48 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -83,7 +83,6 @@ struct cpuidle_driver_kobj; struct cpuidle_device { unsigned int registered:1; unsigned int enabled:1; - unsigned int use_deepest_state:1; unsigned int poll_time_limit:1; unsigned int cpu; ktime_t next_hrtimer; @@ -91,6 +90,7 @@ struct cpuidle_device { int last_state_idx; int last_residency; u64 poll_limit_ns; + u64 forced_idle_latency_limit_ns; struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX]; struct cpuidle_driver_kobj *kobj_driver; @@ -210,7 +210,7 @@ extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev); extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev); -extern void cpuidle_use_deepest_state(bool enable); +extern void cpuidle_use_deepest_state(u64 latency_limit_ns); #else static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev) @@ -218,7 +218,7 @@ static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev) {return -ENODEV; } -static inline void cpuidle_use_deepest_state(bool enable) +static inline void cpuidle_use_deepest_state(u64 latency_limit_ns) { } #endif diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 8dad5aa600ea..0a817e907192 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -165,7 +165,7 @@ static void cpuidle_idle_call(void) * until a proper wakeup interrupt happens. */ - if (idle_should_enter_s2idle() || dev->use_deepest_state) { + if (idle_should_enter_s2idle() || dev->forced_idle_latency_limit_ns) { if (idle_should_enter_s2idle()) { rcu_idle_enter(); @@ -311,7 +311,7 @@ static enum hrtimer_restart idle_inject_timer_fn(struct hrtimer *timer) return HRTIMER_NORESTART; } -void play_idle(unsigned long duration_us) +void play_idle_precise(u64 duration_ns, u64 latency_ns) { struct idle_timer it; @@ -323,29 +323,29 @@ void play_idle(unsigned long duration_us) WARN_ON_ONCE(current->nr_cpus_allowed != 1); WARN_ON_ONCE(!(current->flags & PF_KTHREAD)); WARN_ON_ONCE(!(current->flags & PF_NO_SETAFFINITY)); - WARN_ON_ONCE(!duration_us); + WARN_ON_ONCE(!duration_ns); rcu_sleep_check(); preempt_disable(); current->flags |= PF_IDLE; - cpuidle_use_deepest_state(true); + cpuidle_use_deepest_state(latency_ns); it.done = 0; hrtimer_init_on_stack(&it.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); it.timer.function = idle_inject_timer_fn; - hrtimer_start(&it.timer, ns_to_ktime(duration_us * NSEC_PER_USEC), + hrtimer_start(&it.timer, ns_to_ktime(duration_ns), HRTIMER_MODE_REL_PINNED); while (!READ_ONCE(it.done)) do_idle(); - cpuidle_use_deepest_state(false); + cpuidle_use_deepest_state(0); current->flags &= ~PF_IDLE; preempt_fold_need_resched(); preempt_enable(); } -EXPORT_SYMBOL_GPL(play_idle); +EXPORT_SYMBOL_GPL(play_idle_precise); void cpu_startup_entry(enum cpuhp_state state) {