From patchwork Wed Sep 2 23:25:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lina Iyer X-Patchwork-Id: 256862 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0859C433E2 for ; Wed, 2 Sep 2020 23:27:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F52720C56 for ; Wed, 2 Sep 2020 23:27:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="iXiYlrCG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726877AbgIBX1F (ORCPT ); Wed, 2 Sep 2020 19:27:05 -0400 Received: from mail29.static.mailgun.info ([104.130.122.29]:35991 "EHLO mail29.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726821AbgIBX1D (ORCPT ); Wed, 2 Sep 2020 19:27:03 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1599089222; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=34yRl6SFaHTyY3yXT+BcH3cX7lVCd0YuybGYSb/eyPw=; b=iXiYlrCGSJH2n0Q0HSi6yHWW8qsqiz8iCiac5iG/YTRhG2Mldg032Ucl10FntBL+PSdiYcD/ t6dt3j3+CFSnb+vMDlb8rMbG4mUJg2zb2jZTqr9YEQLgaorNWnHdLHAWmvAMxG0iOo64DEUn O+gvTPuLmlXjnf2uK+EOgYNGQ74= X-Mailgun-Sending-Ip: 104.130.122.29 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-n01.prod.us-east-1.postgun.com with SMTP id 5f502a3b73afa3417eb8cc80 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 02 Sep 2020 23:26:51 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 49EC4C433A1; Wed, 2 Sep 2020 23:26:50 +0000 (UTC) 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 5A748C43391; Wed, 2 Sep 2020 23:26:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 5A748C43391 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=none smtp.mailfrom=ilina@codeaurora.org From: Lina Iyer To: rjw@rjwysocki.net, ulf.hansson@linaro.org, linux-pm@vger.kernel.org Cc: linux-arm-msm@vger.kernel.org, Lina Iyer Subject: [RFC PATCH 2/2] PM / Domains: use device's next wakeup to determine domain idle state Date: Wed, 2 Sep 2020 17:25:46 -0600 Message-Id: <20200902232546.31240-3-ilina@codeaurora.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200902232546.31240-1-ilina@codeaurora.org> References: <20200902232546.31240-1-ilina@codeaurora.org> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org If the device's next event is known, determine if it is worthwhile entering a domain idle state. To find the next wakeup, traverse a domain for all child devices and find out the earliest wakeup value. A parent domain's next wakeup is the earliest of all its child devices and domains. The next wakeup is specified by devices in the domains before they devices are suspended. Update the domain governor logic to determine if it is worthwhile to enter an idle state based on the next wakeup for the domain along with other existing constraints. Signed-off-by: Lina Iyer --- drivers/base/power/domain_governor.c | 87 ++++++++++++++++++++++++++-- include/linux/pm_domain.h | 1 + 2 files changed, 82 insertions(+), 6 deletions(-) diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c index 490ed7deb99a..a71d7281e9c1 100644 --- a/drivers/base/power/domain_governor.c +++ b/drivers/base/power/domain_governor.c @@ -117,6 +117,56 @@ 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) { + if (pdd->dev->power.next_event != KTIME_MAX && + !ktime_before(pdd->dev->power.next_event, now)) { + next_wakeup = READ_ONCE(pdd->dev->power.next_event); + 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) { + struct generic_pm_domain *sd = link->child; + + next_wakeup = sd->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) +{ + s64 idle_time_ns, min_sleep_ns; + ktime_t domain_wakeup = genpd->next_wakeup; + + if (domain_wakeup == KTIME_MAX) + return true; + + 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)); + if (idle_time_ns < min_sleep_ns) + return false; + + return true; +} + static bool __default_power_down_ok(struct dev_pm_domain *pd, unsigned int state) { @@ -210,6 +260,29 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) { struct generic_pm_domain *genpd = pd_to_genpd(pd); struct gpd_link *link; + unsigned int state_idx; + ktime_t now = ktime_get(); + + /* + * 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); + + /* Let's find out what domain idle state, the devices prefer */ + genpd->state_idx = state_idx = genpd->state_count - 1; + while (!next_wakeup_allows_state(genpd, state_idx, now)) { + if (!state_idx) { + genpd->cached_power_down_ok = false; + return false; + } + state_idx--; + } + + genpd->max_off_time_changed = + (state_idx == genpd->cached_power_down_state_idx); if (!genpd->max_off_time_changed) { genpd->state_idx = genpd->cached_power_down_state_idx; @@ -228,18 +301,20 @@ 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--; } - genpd->cached_power_down_state_idx = genpd->state_idx; + genpd->state_idx = state_idx; + genpd->cached_power_down_state_idx = state_idx; return genpd->cached_power_down_ok; } diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index ee11502a575b..9ea6f666967b 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -119,6 +119,7 @@ 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; bool max_off_time_changed; bool cached_power_down_ok; bool cached_power_down_state_idx;