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[209.132.180.67]) by mx.google.com with ESMTP id k126si1404443pfc.180.2016.06.22.12.37.48; Wed, 22 Jun 2016 12:37:50 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-arm-msm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@linaro.org; spf=pass (google.com: best guess record for domain of linux-arm-msm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-arm-msm-owner@vger.kernel.org; dmarc=fail (p=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752034AbcFVThq (ORCPT + 8 others); Wed, 22 Jun 2016 15:37:46 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:36485 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751286AbcFVThp (ORCPT ); Wed, 22 Jun 2016 15:37:45 -0400 Received: by mail-pa0-f52.google.com with SMTP id wo6so19575470pac.3 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=GRA4x1vslCBsmmcMwD/lBf/nxg6araiRvcL2F7FlLQU7M05mRN5EGGG2gIxkj7Jr4e zLlzGkMtZ7n9ZG2UUy1L17R+6eIYXRYAdY5vGdaEdBD+ztoaA/lpPIXRFd2ywJPS5E6/ hwAszqOll8o23y73wBIsJzYJrt43aWjIEhlHUWH1jBojJixmZEXIPwszs0m7nRd63blN 8vMtTUEvGH/Oou21VIQsldT7L+wcIN6xfdA41G85A3nON7QfdvRkMiz2VYDTCgxpj5dT Ey/nga6YvPL4nPH/pROmD9E6/t4XwHo9enqmaJWkQU2N9D0/eWjNo5ba3joTmy5jU/mu HPuA== X-Gm-Message-State: ALyK8tJaSCc3aWXSb5+zMJxsjWEt3Fg+lM3hU7zIo+K9G8k6Hk+0NqkrXF1p7wWE1rpGDAO8 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 Cc: geert@linux-m68k.org, k.kozlowski@samsung.com, andy.gross@linaro.org, sboyd@codeaurora.org, linux-arm-msm@vger.kernel.org, lorenzo.pieralisi@arm.com, ahaslam@baylibre.com, mtitinger@baylibre.com, Lina Iyer 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> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org 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(-) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html 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;