From patchwork Thu Aug 25 19:51:40 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lina Iyer X-Patchwork-Id: 9299797 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B2A0F60757 for ; Thu, 25 Aug 2016 20:03:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A2BB2292B1 for ; Thu, 25 Aug 2016 20:03:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9722829384; Thu, 25 Aug 2016 20:03:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 37AF4292B1 for ; Thu, 25 Aug 2016 20:03:31 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bd0rO-0004Hn-8J; Thu, 25 Aug 2016 20:02:46 +0000 Received: from mail-pf0-x231.google.com ([2607:f8b0:400e:c00::231]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bd0hX-0002pn-6I for linux-arm-kernel@lists.infradead.org; Thu, 25 Aug 2016 19:52:37 +0000 Received: by mail-pf0-x231.google.com with SMTP id h186so20605140pfg.3 for ; Thu, 25 Aug 2016 12:52:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=gCuKDtDmHYDLbWXeioHIifudz6JbjkpkXDksVfcJIGk=; b=depZFjbxTN7lJzFeLsXMqYloILiqzC0NBRF87Dr6eAJY4uYAVI9r0kAF3io6cCXbue j+kqL0SMfimjbb4taBCl8aT5bjM1s5Ih1MkHLHNi+ObmXSmmS1/IHQF2CZZDsXsrXZ4E 22+fYEEIJUG0vjiSyjHDpw7Zs8eDehULpFSIA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=gCuKDtDmHYDLbWXeioHIifudz6JbjkpkXDksVfcJIGk=; b=Zz4kMS8CeGoyU4LAKLWFsGSfoPWvEqAy7a0jXh6l9cVhaw5Efwd0Xt590/QrM2fSB6 qEI5ny/skdS3a0AIjQxPGOFtb32Gv4k/RlfYE5rlQFRO2ODKyL2gs6dHRi4+FlUq2vIL w8LtqiSTD2wnKJkD+7w/6VCutJrNDUjownMOFIXKS7xDm6lVzSikaeUjVH4Qso4mMdVW Q4B8F3Z7KKoLYJNryzpPo9Lis1mIUgxiIweCxtkshYmTYm+2mmv8brFEARHxHpRt8iEm ROIm1q3Q1XrioGEpCbQFDLhx9WinLokwQ21f1Ve92w0T/+LlaBB6ElMsRsSxUneySNrb HQhg== X-Gm-Message-State: AE9vXwPr0dicgZLqjecSbEHCRimT3avm5U3dQMQLTJlW2ZIXdC3+4EBez4xB1MyfM2ezcriT X-Received: by 10.98.0.83 with SMTP id 80mr19558484pfa.78.1472154738809; Thu, 25 Aug 2016 12:52:18 -0700 (PDT) Received: from ubuntu.localdomain (i-global254.qualcomm.com. [199.106.103.254]) by smtp.gmail.com with ESMTPSA id i62sm22783375pfg.62.2016.08.25.12.52.16 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 25 Aug 2016 12:52:17 -0700 (PDT) From: Lina Iyer To: ulf.hansson@linaro.org, khilman@kernel.org, rjw@rjwysocki.net, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 10/16] PM / cpu_domains: Add PM Domain governor for CPUs Date: Thu, 25 Aug 2016 13:51:40 -0600 Message-Id: <1472154706-40119-11-git-send-email-lina.iyer@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1472154706-40119-1-git-send-email-lina.iyer@linaro.org> References: <1472154706-40119-1-git-send-email-lina.iyer@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160825_125235_364904_ECEF51DE X-CRM114-Status: GOOD ( 19.45 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lorenzo.pieralisi@arm.com, Juri.Lelli@arm.com, linux-arm-msm@vger.kernel.org, sboyd@codeaurora.org, brendan.jackman@arm.com, sudeep.holla@arm.com, andy.gross@linaro.org, Lina Iyer MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP A PM domain comprising of CPUs may be powered off when all the CPUs in the domain are powered down. Powering down a CPU domain is generally a expensive operation and therefore the power performance trade offs should be considered. The time between the last CPU powering down and the first CPU powering up in a domain, is the time available for the domain to sleep. Ideally, the sleep time of the domain should fulfill the residency requirement of the domains' idle state. To do this effectively, read the time before the wakeup of the cluster's CPUs and ensure that the domain's idle state sleep time guarantees the QoS requirements of each of the CPU, the PM QoS CPU_DMA_LATENCY and the state's residency. Signed-off-by: Lina Iyer --- drivers/base/power/cpu_domains.c | 80 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 79 insertions(+), 1 deletion(-) diff --git a/drivers/base/power/cpu_domains.c b/drivers/base/power/cpu_domains.c index 8bf61e2..79fa4ae 100644 --- a/drivers/base/power/cpu_domains.c +++ b/drivers/base/power/cpu_domains.c @@ -17,9 +17,12 @@ #include #include #include +#include +#include #include #include #include +#include #define CPU_PD_NAME_MAX 36 @@ -51,6 +54,81 @@ static inline struct cpu_pm_domain *to_cpu_pd(struct generic_pm_domain *d) return res; } +static bool cpu_pd_down_ok(struct dev_pm_domain *pd) +{ + struct generic_pm_domain *genpd = pd_to_genpd(pd); + struct cpu_pm_domain *cpu_pd = to_cpu_pd(genpd); + int qos_ns = pm_qos_request(PM_QOS_CPU_DMA_LATENCY); + u64 sleep_ns; + ktime_t earliest, next_wakeup; + int cpu; + int i; + + /* Reset the last set genpd state, default to index 0 */ + genpd->state_idx = 0; + + /* We don't want to power down, if QoS is 0 */ + if (!qos_ns) + return false; + + /* + * Find the sleep time for the cluster. + * The time between now and the first wake up of any CPU that + * are in this domain hierarchy is the time available for the + * domain to be idle. + * + * We only care about the next wakeup for any online CPU in that + * cluster. Hotplug off any of the CPUs that we care about will + * wait on the genpd lock, until we are done. Any other CPU hotplug + * is not of consequence to our sleep time. + */ + earliest = ktime_set(KTIME_SEC_MAX, 0); + for_each_cpu_and(cpu, cpu_pd->cpus, cpu_online_mask) { + next_wakeup = tick_nohz_get_next_wakeup(cpu); + if (earliest.tv64 > next_wakeup.tv64) + earliest = next_wakeup; + } + + sleep_ns = ktime_to_ns(ktime_sub(earliest, ktime_get())); + if (sleep_ns <= 0) + return false; + + /* + * Find the deepest sleep state that satisfies the residency + * requirement and the QoS constraint + */ + for (i = genpd->state_count - 1; i >= 0; i--) { + u64 state_sleep_ns; + + state_sleep_ns = genpd->states[i].power_off_latency_ns + + genpd->states[i].power_on_latency_ns + + genpd->states[i].residency_ns; + + /* + * If we can't sleep to save power in the state, move on + * to the next lower idle state. + */ + if (state_sleep_ns > sleep_ns) + continue; + + /* + * We also don't want to sleep more than we should to + * gaurantee QoS. + */ + if (state_sleep_ns < (qos_ns * NSEC_PER_USEC)) + break; + } + + if (i >= 0) + genpd->state_idx = i; + + return (i >= 0); +} + +static struct dev_power_governor cpu_pd_gov = { + .power_down_ok = cpu_pd_down_ok, +}; + static int cpu_pd_power_on(struct generic_pm_domain *genpd) { struct cpu_pm_domain *pd = to_cpu_pd(genpd); @@ -172,7 +250,7 @@ struct generic_pm_domain *cpu_pd_init(struct generic_pm_domain *genpd, list_add_rcu(&pd->link, &of_cpu_pd_list); mutex_unlock(&cpu_pd_list_lock); - ret = pm_genpd_init(genpd, &simple_qos_governor, false); + ret = pm_genpd_init(genpd, &cpu_pd_gov, false); if (ret) { pr_err("Unable to initialize domain %s\n", genpd->name); goto fail;