From patchwork Wed Jun 22 19:36:44 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lina Iyer X-Patchwork-Id: 9193667 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 2076A6075F for ; Wed, 22 Jun 2016 19:41:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0E19428402 for ; Wed, 22 Jun 2016 19:41:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 01F3928416; Wed, 22 Jun 2016 19:41:10 +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 97BFA28402 for ; Wed, 22 Jun 2016 19:41:10 +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 1bFnzz-0003Ho-08; Wed, 22 Jun 2016 19:39:43 +0000 Received: from mail-pa0-x234.google.com ([2607:f8b0:400e:c03::234]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bFnyO-0001bp-Bs for linux-arm-kernel@lists.infradead.org; Wed, 22 Jun 2016 19:38:06 +0000 Received: by mail-pa0-x234.google.com with SMTP id b13so19609959pat.0 for ; Wed, 22 Jun 2016 12:37:45 -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=qVCBhj5X2XThs+WRt1uNanITOvn9VYLNtJh9zRDX20M=; b=B73ukQljvyJPGiu0wa4FRD2k7SrD2Y8IxGK6Pi63gM2IYG2wYLlQPbI/pu31R6GMmm N9db6AxE5tugccwWTKLLnCul8tNhaeiPBbG+qbdoS+qlC7DD1zbqJklPfUOikZf7UHyU 2S3kos/QlvazaF/0pUUJ28gjQGFr25dgpg87U= 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=qVCBhj5X2XThs+WRt1uNanITOvn9VYLNtJh9zRDX20M=; b=f1A71hEIu4SkHjrUvWKcocSdkfklrdWs30fvSrBk5jpAAQ/dFx3O9voVayC8Z/KfTa ei8LWKID5cIByAFBsBrCj7delLwQkekFWpc2zrUB82xTWRORlomki8wL5LBgRaQqxK4w uzIIHSRYg/O/MhWx1bpOhqcOqAxdm9JnosN2fQUt0VGtPB8Cdhf0FCDXD/aNzqdLvT9J 4Ato6n+fG95DhH3NhBS0VgZD5Ke0No0Byu6k9rIFy+H3gGWuRoFjw2zwgFtY3SPlEVPq nTtuWSuRH16TcuQQXMVcU9irpY11vSgdSVxllWz/14m+WD7QJQi15WSYQT0Lkkydq13O 0Pow== X-Gm-Message-State: ALyK8tK8vkAysvRIizhWmRBRVJqqeAeqtsiDKnWa997Ej8ICCktWdNFZmzZg4v6BJFTqozTE X-Received: by 10.67.23.197 with SMTP id ic5mr11875177pad.127.1466624265066; Wed, 22 Jun 2016 12:37:45 -0700 (PDT) Received: from ubuntu.localdomain ([172.56.9.151]) by smtp.gmail.com with ESMTPSA id t4sm1563368paw.32.2016.06.22.12.37.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 22 Jun 2016 12:37:43 -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 09/14] PM / cpu_domains: Add PM Domain governor for CPUs Date: Wed, 22 Jun 2016 13:36:44 -0600 Message-Id: <1466624209-27432-10-git-send-email-lina.iyer@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1466624209-27432-1-git-send-email-lina.iyer@linaro.org> References: <1466624209-27432-1-git-send-email-lina.iyer@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160622_123804_563667_A5966B48 X-CRM114-Status: GOOD ( 19.36 ) 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: k.kozlowski@samsung.com, lorenzo.pieralisi@arm.com, ahaslam@baylibre.com, linux-arm-msm@vger.kernel.org, sboyd@codeaurora.org, geert@linux-m68k.org, Lina Iyer , andy.gross@linaro.org, mtitinger@baylibre.com 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 63dd45d..1803fde 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 @@ -52,6 +55,81 @@ 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_attach_cpu(struct cpu_pm_domain *cpu_pd, int cpu) { int ret; @@ -144,7 +222,7 @@ static struct generic_pm_domain *of_init_cpu_pm_domain(struct device_node *dn, /* Register the CPU genpd */ pr_debug("adding %s as CPU PM domain\n", pd->genpd->name); - ret = pm_genpd_init(pd->genpd, &simple_qos_governor, false); + ret = pm_genpd_init(pd->genpd, &cpu_pd_gov, false); if (ret) { pr_err("Unable to initialize domain %s\n", dn->full_name); goto fail;