From patchwork Fri Nov 6 16:48:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lina Iyer X-Patchwork-Id: 11887411 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CCD4F15E6 for ; Fri, 6 Nov 2020 16:48:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3477217A0 for ; Fri, 6 Nov 2020 16:48:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="hqiLAP5C" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726139AbgKFQsd (ORCPT ); Fri, 6 Nov 2020 11:48:33 -0500 Received: from m42-4.mailgun.net ([69.72.42.4]:54211 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726415AbgKFQsd (ORCPT ); Fri, 6 Nov 2020 11:48:33 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1604681311; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=vbVqxdfpXgPQ9hKPEOY6L3TJ3+uw4ScU+tZxEf/suMY=; b=hqiLAP5Cwn/DMaEziEY2fe8+bcme/SNPP/QhDOZ7tBHFz73vxoZVdrlAeycREe0vhiIrUuod tll4q3fyvmxvbUdYSgwa7BKddZXzhgUsu2kPSyedwu3/HNPu2wiZydaJ9fBbybNu8ogvXbaj Vd63sBQXwjiDyimXxJ4CFHjx2ec= X-Mailgun-Sending-Ip: 69.72.42.4 X-Mailgun-Sid: WyI5ZDFmMiIsICJsaW51eC1wbUB2Z2VyLmtlcm5lbC5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n03.prod.us-east-1.postgun.com with SMTP id 5fa57e57c6df09e2f22a8c5f (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 06 Nov 2020 16:48:23 GMT Sender: ilina=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 1802AC433FE; Fri, 6 Nov 2020 16:48:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=ALL_TRUSTED,BAYES_00,SPF_FAIL, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from codeaurora.org (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: ilina) by smtp.codeaurora.org (Postfix) with ESMTPSA id E8D93C433C6; Fri, 6 Nov 2020 16:48:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org E8D93C433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=ilina@codeaurora.org From: Lina Iyer To: rjw@rjwysocki.net, ulf.hansson@linaro.org Cc: linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org, Lina Iyer Subject: [PATCH v5 1/2] PM / domains: inform PM domain of a device's next wakeup Date: Fri, 6 Nov 2020 09:48:10 -0700 Message-Id: <20201106164811.3698-2-ilina@codeaurora.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201106164811.3698-1-ilina@codeaurora.org> References: <20201106164811.3698-1-ilina@codeaurora.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Some devices may have a predictable interrupt pattern while executing usecases. An example would be the VSYNC interrupt associated with display devices. A 60 Hz display could cause a interrupt every 16 ms. If the device were in a PM domain, the domain would need to be powered up for device to resume and handle the interrupt. Entering a domain idle state saves power, only if the residency of the idle state is met. Without knowing the idle duration of the domain, the governor would just choose the deepest idle state that matches the QoS requirements. The domain might be powered off just as the device is expecting to wake up. If devices could inform PM frameworks of their next event, the parent PM domain's idle duration can be determined. So let's add the dev_pm_genpd_set_next_wakeup() API for the device to inform PM domains of the impending wakeup. This information will be the domain governor to determine the best idle state given the wakeup. Signed-off-by: Lina Iyer Reviewed-by: Ulf Hansson --- Changes in v5: - Fix commit text as pointed by Ulf - Use -EOPNOTSUPP Changes in v4: - Use PM domain data to store next_wakeup - Drop runtime PM documentation Changes in v3: - Fix unwanted change Changes in v2: - Update documentation - Remove runtime PM enabled check - Update commit text --- drivers/base/power/domain.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/pm_domain.h | 8 ++++++++ 2 files changed, 44 insertions(+) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 743268996336..34b90e77e0cd 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -408,6 +408,41 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state) } EXPORT_SYMBOL_GPL(dev_pm_genpd_set_performance_state); +/** + * dev_pm_genpd_set_next_wakeup - Notify PM framework of an impending wakeup. + * + * @dev: Device to handle + * @next: impending interrupt/wakeup for the device + * + * Allow devices to inform of the next wakeup. But, if the domain were already + * powered off, we will not wakeup the domain to recompute it's idle duration. + */ +int dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next) +{ + struct generic_pm_domain *genpd; + struct generic_pm_domain_data *gpd_data; + int ret = -EINVAL; + + genpd = dev_to_genpd_safe(dev); + if (!genpd) + return -ENODEV; + + if (WARN_ON(!dev->power.subsys_data || + !dev->power.subsys_data->domain_data)) + return ret; + + genpd_lock(genpd); + gpd_data = to_gpd_data(dev->power.subsys_data->domain_data); + if (ktime_before(ktime_get(), next)) { + gpd_data->next_wakeup = next; + ret = 0; + } + genpd_unlock(genpd); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_genpd_set_next_wakeup); + static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed) { unsigned int state_idx = genpd->state_idx; @@ -1431,6 +1466,7 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev) gpd_data->td.constraint_changed = true; gpd_data->td.effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS; gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier; + gpd_data->next_wakeup = KTIME_MAX; spin_lock_irq(&dev->power.lock); diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 1ad0ec481416..d7875bfde7f4 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -9,6 +9,7 @@ #define _LINUX_PM_DOMAIN_H #include +#include #include #include #include @@ -191,6 +192,7 @@ struct generic_pm_domain_data { struct notifier_block *power_nb; int cpu; unsigned int performance_state; + ktime_t next_wakeup; void *data; }; @@ -217,6 +219,7 @@ int pm_genpd_remove(struct generic_pm_domain *genpd); int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state); int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb); int dev_pm_genpd_remove_notifier(struct device *dev); +int dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next); extern struct dev_power_governor simple_qos_governor; extern struct dev_power_governor pm_domain_always_on_gov; @@ -275,6 +278,11 @@ static inline int dev_pm_genpd_remove_notifier(struct device *dev) return -ENOTSUPP; } +static inline int dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next) +{ + return -EOPNOTSUPP; +} + #define simple_qos_governor (*(struct dev_power_governor *)(NULL)) #define pm_domain_always_on_gov (*(struct dev_power_governor *)(NULL)) #endif From patchwork Fri Nov 6 16:48:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lina Iyer X-Patchwork-Id: 11887407 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 16F9A6A2 for ; Fri, 6 Nov 2020 16:48:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E27DE217A0 for ; Fri, 6 Nov 2020 16:48:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="K6L/zfJo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726010AbgKFQsd (ORCPT ); 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spf=fail smtp.mailfrom=ilina@codeaurora.org From: Lina Iyer To: rjw@rjwysocki.net, ulf.hansson@linaro.org Cc: linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org, Lina Iyer Subject: [PATCH v5 2/2] PM / Domains: use device's next wakeup to determine domain idle state Date: Fri, 6 Nov 2020 09:48:11 -0700 Message-Id: <20201106164811.3698-3-ilina@codeaurora.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201106164811.3698-1-ilina@codeaurora.org> References: <20201106164811.3698-1-ilina@codeaurora.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Currently, a PM domain's idle state is determined based on whether the QoS requirements are met. This may not save power, if the idle state residency requirements are not met. CPU PM domains use the next timer wakeup for the CPUs in the domain to determine the sleep duration of the domain. This is compared with the idle state residencies to determine the optimal idle state. For other PM domains, determining the sleep length is not that straight forward. But if the device's next_event is available, we can use that to determine the sleep duration of the PM domain. Let's update the domain governor logic to check for idle state residency based on the next wakeup of devices as well as QoS constraints. Signed-off-by: Lina Iyer --- Changes in v5: - Minor code changes suggested by Rafel Changes in v4: - Update to use next_wakeup from struct generic_pm_domain_data. Changes in v3: - None Changes in v2: - Fix state_idx type to hold negative value. - Update commit text. --- drivers/base/power/domain_governor.c | 81 ++++++++++++++++++++++++++-- include/linux/pm_domain.h | 1 + 2 files changed, 77 insertions(+), 5 deletions(-) diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c index 490ed7deb99a..fee050c6ea6a 100644 --- a/drivers/base/power/domain_governor.c +++ b/drivers/base/power/domain_governor.c @@ -117,6 +117,47 @@ static bool default_suspend_ok(struct device *dev) return td->cached_suspend_ok; } +static void update_domain_next_wakeup(struct generic_pm_domain *genpd, ktime_t now) +{ + ktime_t domain_wakeup = KTIME_MAX; + ktime_t next_wakeup; + struct pm_domain_data *pdd; + struct gpd_link *link; + + /* Find the earliest wakeup for all devices in the domain */ + list_for_each_entry(pdd, &genpd->dev_list, list_node) { + next_wakeup = to_gpd_data(pdd)->next_wakeup; + if (next_wakeup != KTIME_MAX && !ktime_before(next_wakeup, now)) + if (ktime_before(next_wakeup, domain_wakeup)) + domain_wakeup = next_wakeup; + } + + /* Then find the earliest wakeup of from all the child domains */ + list_for_each_entry(link, &genpd->parent_links, parent_node) { + next_wakeup = link->child->next_wakeup; + if (next_wakeup != KTIME_MAX && !ktime_before(next_wakeup, now)) + if (ktime_before(next_wakeup, domain_wakeup)) + domain_wakeup = next_wakeup; + } + + genpd->next_wakeup = domain_wakeup; +} + +static bool next_wakeup_allows_state(struct generic_pm_domain *genpd, + unsigned int state, ktime_t now) +{ + ktime_t domain_wakeup = genpd->next_wakeup; + s64 idle_time_ns, min_sleep_ns; + + min_sleep_ns = genpd->states[state].power_off_latency_ns + + genpd->states[state].power_on_latency_ns + + genpd->states[state].residency_ns; + + idle_time_ns = ktime_to_ns(ktime_sub(domain_wakeup, now)); + + return idle_time_ns >= min_sleep_ns; +} + static bool __default_power_down_ok(struct dev_pm_domain *pd, unsigned int state) { @@ -209,8 +250,34 @@ static bool __default_power_down_ok(struct dev_pm_domain *pd, static bool default_power_down_ok(struct dev_pm_domain *pd) { struct generic_pm_domain *genpd = pd_to_genpd(pd); + int state_idx = genpd->state_count - 1; + ktime_t now = ktime_get(); struct gpd_link *link; + /* + * Find the next wakeup from devices that can determine their own wakeup + * to find when the domain would wakeup and do it for every device down + * the hierarchy. It is not worth while to sleep if the state's residency + * cannot be met. + */ + update_domain_next_wakeup(genpd, now); + if (genpd->next_wakeup != KTIME_MAX) { + /* Let's find out the deepest domain idle state, the devices prefer */ + while (state_idx >= 0) { + if (next_wakeup_allows_state(genpd, state_idx, now)) { + genpd->max_off_time_changed = true; + break; + } + state_idx--; + } + + if (state_idx < 0) { + state_idx = 0; + genpd->cached_power_down_ok = false; + goto done; + } + } + if (!genpd->max_off_time_changed) { genpd->state_idx = genpd->cached_power_down_state_idx; return genpd->cached_power_down_ok; @@ -228,17 +295,21 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) genpd->max_off_time_ns = -1; genpd->max_off_time_changed = false; genpd->cached_power_down_ok = true; - genpd->state_idx = genpd->state_count - 1; - /* Find a state to power down to, starting from the deepest. */ - while (!__default_power_down_ok(pd, genpd->state_idx)) { - if (genpd->state_idx == 0) { + /* + * Find a state to power down to, starting from the state + * determined by the next wakeup. + */ + while (!__default_power_down_ok(pd, state_idx)) { + if (state_idx == 0) { genpd->cached_power_down_ok = false; break; } - genpd->state_idx--; + state_idx--; } +done: + genpd->state_idx = state_idx; genpd->cached_power_down_state_idx = genpd->state_idx; return genpd->cached_power_down_ok; } diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index d7875bfde7f4..49982cd58bfd 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -130,6 +130,7 @@ struct generic_pm_domain { unsigned int state); struct gpd_dev_ops dev_ops; s64 max_off_time_ns; /* Maximum allowed "suspended" time. */ + ktime_t next_wakeup; /* Maintained by the domain governor */ bool max_off_time_changed; bool cached_power_down_ok; bool cached_power_down_state_idx;