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 X-Spam-Level: X-Spam-Status: No, score=-6.4 required=3.0 tests=BODY_QUOTE_MALF_MSGID, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 7AA68C4CEC9 for ; Wed, 18 Sep 2019 19:30:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 427482249C for ; Wed, 18 Sep 2019 19:30:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="oiSbz40s" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727805AbfIRTas (ORCPT ); Wed, 18 Sep 2019 15:30:48 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:43031 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725899AbfIRTas (ORCPT ); Wed, 18 Sep 2019 15:30:48 -0400 Received: by mail-pg1-f195.google.com with SMTP id u72so412598pgb.10 for ; Wed, 18 Sep 2019 12:30:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=HLzPRK3GAXNM5xLTblOxGV9Q6DGatzHoWsFQNs/caP0=; b=oiSbz40siiKmYPogUFoLfuMN4h1aZgbTxVs57nkOvlUW3DUYQirAdI/q3rrV7RiBlf 6rZoqxQ/5q5Szu+tiLtwBhFU+M4Z2In5WsdsOgYNr8ia9WblIefGNEOMY0umzxsQxK2k BdT5DoB7fa/dgNb8GYWnPGhgDcw0F5yVjsTkqR72FR/WNPNLNsdNA+MOLJYEbrdtjfjz KnCEeNTc0DJFWcbzEznLFv7js367/SySemn/nDo/Xwzyh174yd93ef0nXc20jm6pogYl Wsnv8uh8woKpA8sWqB2KmWOPq78n2cicXfjOuuAesbfa/fMCKiWgZ1IIkRIEtMYgcF3z k1hQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=HLzPRK3GAXNM5xLTblOxGV9Q6DGatzHoWsFQNs/caP0=; b=sCjRLBb8Yc/C5PIf2qpKQCRPSm3iY3ITIg2VZqtgJoxeAHk4KyiGweWNiKuhWQSh8C 79pcq9uxo5u58rdh2E7d7iiPn1DN6zgM8UsNj/QZ0cnqAWE6OZoH2bZRzPPo1Edy2+6n GyLiBUDOjpNzi306cUddFjodwhLOmrsN5Yq59ds7vPAWbcw0V2aL0JlPvGxD7Yr79N5F teIzy9cgZnKFE06X8hCygSFN8h5IWMs7IL6zPxvN74FIszTccRhESIplxpD35ycmIBH1 BvKf/EkKjyyv5hy8YafFzZWnRPEbLKJ0iyO7EpoT0MzDZUvwDBKMcfgywjxEyEhfdbaw kq9Q== X-Gm-Message-State: APjAAAVg73avvkWNVvIzFr2NDpwQak82r2zWlhLCdPTjAE3dtyPmomHR s8owDkmGfgn8aQYOe2NIPX3XLg== X-Google-Smtp-Source: APXvYqw4Zn7xmwjEJVqTKdp3MaG8FdSq6t+0JVX5q/nTofC9TRVTEvsIAb7bIdvSCZvV7+mt8DqxJA== X-Received: by 2002:a62:aa0f:: with SMTP id e15mr5846419pff.160.1568835046043; Wed, 18 Sep 2019 12:30:46 -0700 (PDT) Received: from xps15 (S0106002369de4dac.cg.shawcable.net. [68.147.8.254]) by smtp.gmail.com with ESMTPSA id k5sm6029441pgo.45.2019.09.18.12.30.44 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 18 Sep 2019 12:30:45 -0700 (PDT) Date: Wed, 18 Sep 2019 13:30:43 -0600 From: Mathieu Poirier To: Daniel Lezcano Cc: rafael@kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Ingo Molnar , Peter Zijlstra Subject: Re: [PATCH 1/3] cpuidle: play_idle: Make play_idle more flexible Message-ID: <20190918193043.GA24433@xps15> References: <20190909145015.26317-1-daniel.lezcano@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190909145015.26317-1-daniel.lezcano@linaro.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Mon, Sep 09, 2019 at 04:50:13PM +0200, Daniel Lezcano wrote: > The play_idle function has two users, the intel powerclamp and the > idle_injection. > > The idle injection cooling device uses the function via the > idle_injection powercap's APIs. Unfortunately, play_idle is currently > limited by the idle state depth: by default the deepest idle state is > selected. On the ARM[64] platforms, most of the time it is the cluster > idle state, the exit latency and the residency can be very high. That > reduces the scope of the idle injection usage because the impact on > the performances can be very significant. > > If the idle injection cycles can be done with a shallow state like a > retention state, the cooling effect would eventually give similar > results than the cpufreq cooling device. > > In order to prepare the function to receive an idle state parameter, > let's replace the 'use_deepest_state' boolean field with 'use_state' > and use this value to enter the specific idle state. > > The current code keeps the default behavior which is go to the deepest > idle state. > > Signed-off-by: Daniel Lezcano > --- > drivers/cpuidle/cpuidle.c | 21 +++++++++++---------- > include/linux/cpuidle.h | 14 +++++++------- > kernel/sched/idle.c | 10 +++++----- > 3 files changed, 23 insertions(+), 22 deletions(-) > > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c > index 0895b988fa92..f8b54f277589 100644 > --- a/drivers/cpuidle/cpuidle.c > +++ b/drivers/cpuidle/cpuidle.c > @@ -99,31 +99,31 @@ static int find_deepest_state(struct cpuidle_driver *drv, > } > > /** > - * cpuidle_use_deepest_state - Set/clear governor override flag. > - * @enable: New value of the flag. > + * cpuidle_use_state - Force the cpuidle framework to enter an idle state. > + * @state: An integer for an idle state > * > - * Set/unset the current CPU to use the deepest idle state (override governors > - * going forward if set). > + * Specify an idle state the cpuidle framework must step in and bypass > + * the idle state selection process. > */ > -void cpuidle_use_deepest_state(bool enable) > +void cpuidle_use_state(int state) > { > struct cpuidle_device *dev; > > preempt_disable(); > dev = cpuidle_get_device(); > if (dev) > - dev->use_deepest_state = enable; > + dev->use_state = state; > preempt_enable(); > } > > /** > * cpuidle_find_deepest_state - Find the deepest available idle state. > - * @drv: cpuidle driver for the given CPU. > - * @dev: cpuidle device for the given CPU. > */ > -int cpuidle_find_deepest_state(struct cpuidle_driver *drv, > - struct cpuidle_device *dev) > +int cpuidle_find_deepest_state(void) > { > + struct cpuidle_device *dev = cpuidle_get_device(); > + struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); > + > return find_deepest_state(drv, dev, UINT_MAX, 0, false); > } > > @@ -554,6 +554,7 @@ static void __cpuidle_unregister_device(struct cpuidle_device *dev) > static void __cpuidle_device_init(struct cpuidle_device *dev) > { > memset(dev->states_usage, 0, sizeof(dev->states_usage)); > + dev->use_state = CPUIDLE_STATE_NOUSE; > dev->last_residency = 0; > dev->next_hrtimer = 0; > } > diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h > index 1a9f54eb3aa1..a1839122e219 100644 > --- a/include/linux/cpuidle.h > +++ b/include/linux/cpuidle.h > @@ -15,6 +15,7 @@ > #include > #include > > +#define CPUIDLE_STATE_NOUSE -1 > #define CPUIDLE_STATE_MAX 10 > #define CPUIDLE_NAME_LEN 16 > #define CPUIDLE_DESC_LEN 32 > @@ -80,11 +81,12 @@ 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; > + Spurious newline > ktime_t next_hrtimer; > > + int use_state; > int last_state_idx; > int last_residency; > u64 poll_limit_ns; > @@ -200,19 +202,17 @@ static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } > #endif > > #ifdef CONFIG_CPU_IDLE > -extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, > - struct cpuidle_device *dev); > +extern int cpuidle_find_deepest_state(void); > 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_state(int state); > #else > -static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, > - struct cpuidle_device *dev) > +static inline int cpuidle_find_deepest_state(void) > {return -ENODEV; } > 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_state(int state) > { > } > #endif > diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c > index b98283fc6914..17da9cb309e1 100644 > --- a/kernel/sched/idle.c > +++ b/kernel/sched/idle.c > @@ -165,7 +165,8 @@ 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->use_state != CPUIDLE_STATE_NOUSE) { > if (idle_should_enter_s2idle()) { > rcu_idle_enter(); > > @@ -181,8 +182,7 @@ static void cpuidle_idle_call(void) > tick_nohz_idle_stop_tick(); > rcu_idle_enter(); > > - next_state = cpuidle_find_deepest_state(drv, dev); > - call_cpuidle(drv, dev, next_state); > + call_cpuidle(drv, dev, dev->use_state); > } else { > bool stop_tick = true; > > @@ -328,7 +328,7 @@ void play_idle(unsigned long duration_us) > rcu_sleep_check(); > preempt_disable(); > current->flags |= PF_IDLE; > - cpuidle_use_deepest_state(true); > + cpuidle_use_state(cpuidle_find_deepest_state()); > > it.done = 0; > hrtimer_init_on_stack(&it.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); > @@ -339,7 +339,7 @@ void play_idle(unsigned long duration_us) > while (!READ_ONCE(it.done)) > do_idle(); > > - cpuidle_use_deepest_state(false); > + cpuidle_use_state(CPUIDLE_STATE_NOUSE); > current->flags &= ~PF_IDLE; > > preempt_fold_need_resched(); With the above: Acked-by: Mathieu Poirier > -- > 2.17.1 >