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: 11887405 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 1ED88921 for ; Fri, 6 Nov 2020 16:48:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E294E22227 for ; Fri, 6 Nov 2020 16:48:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="Qy8eC1wf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725868AbgKFQsc (ORCPT ); Fri, 6 Nov 2020 11:48:32 -0500 Received: from m42-4.mailgun.net ([69.72.42.4]:15987 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726010AbgKFQsc (ORCPT ); Fri, 6 Nov 2020 11:48:32 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1604681310; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=2Mx7Wwy0iehpdTNmIVKBBjVvQlP2FvvqKcAd5GEGnjU=; b=Qy8eC1wfod7uqc2l4R9dwfv+njym+9p7O89IRwC9Ov1QIYpQFBxABTZwPjNtYdxpPs+iCVMu SVfGAeiMgM0+7aOXCi70J7a8bnyuDKtxhVXGV5AzfGUIkaiH5+boFQllY+pMmdrJQAZpkSw/ StxaBWiodTOEQy+nvpbHcRCi5hg= X-Mailgun-Sending-Ip: 69.72.42.4 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n07.prod.us-east-1.postgun.com with SMTP id 5fa57e58b82e1b98c66c5d8a (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 06 Nov 2020 16:48:24 GMT Sender: ilina=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id DC983C433C6; 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 D2F5BC433C8; Fri, 6 Nov 2020 16:48:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D2F5BC433C8 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 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-arm-msm@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;