From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 71E9ACA9EBB for ; Thu, 24 Oct 2019 16:36:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 517FB21906 for ; Thu, 24 Oct 2019 16:36:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2503465AbfJXQgQ (ORCPT ); Thu, 24 Oct 2019 12:36:16 -0400 Received: from foss.arm.com ([217.140.110.172]:56038 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2503451AbfJXQdR (ORCPT ); Thu, 24 Oct 2019 12:33:17 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C7B5832B; Thu, 24 Oct 2019 09:33:01 -0700 (PDT) Received: from bogus (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DE9223F71F; Thu, 24 Oct 2019 09:32:59 -0700 (PDT) Date: Thu, 24 Oct 2019 17:32:57 +0100 From: Sudeep Holla To: Ulf Hansson Cc: "Rafael J . Wysocki" , Daniel Lezcano , Lorenzo Pieralisi , Mark Rutland , Lina Iyer , linux-pm@vger.kernel.org, Rob Herring , Vincent Guittot , Stephen Boyd , Sudeep Holla , Bjorn Andersson , Kevin Hilman , linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH 12/13] cpuidle: psci: Manage runtime PM in the idle path Message-ID: <20191024163257.GC22036@bogus> References: <20191010113937.15962-1-ulf.hansson@linaro.org> <20191010113937.15962-13-ulf.hansson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191010113937.15962-13-ulf.hansson@linaro.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Thu, Oct 10, 2019 at 01:39:36PM +0200, Ulf Hansson wrote: > In case we have succeeded to attach a CPU to its PM domain, let's deploy > runtime PM support for the corresponding attached device, to allow the CPU > to be powered-managed accordingly. > > To set the triggering point for when runtime PM reference counting should > be done, let's store the index of deepest idle state for the CPU in the per > CPU struct. Then use this index to compare the selected idle state index > when entering idle, as to understand whether runtime PM reference counting > is needed or not. > > Note that, from the hierarchical point view, there may be good reasons to > do runtime PM reference counting even on shallower idle states, but at this > point this isn't supported, mainly due to limitations set by the generic PM > domain. > > Signed-off-by: Ulf Hansson > --- > drivers/cpuidle/cpuidle-psci.c | 21 +++++++++++++++++++-- > 1 file changed, 19 insertions(+), 2 deletions(-) > > diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c > index 1510422c7a53..0919b40c1a85 100644 > --- a/drivers/cpuidle/cpuidle-psci.c > +++ b/drivers/cpuidle/cpuidle-psci.c > @@ -16,6 +16,7 @@ > #include > #include > #include > +#include > #include > > #include > @@ -25,6 +26,7 @@ > > struct psci_cpuidle_data { > u32 *psci_states; > + u32 rpm_state_id; > struct device *dev; > }; > > @@ -50,14 +52,28 @@ static int psci_enter_idle_state(struct cpuidle_device *dev, > struct cpuidle_driver *drv, int idx) > { > int ret; > - u32 *states = __this_cpu_read(psci_cpuidle_data.psci_states); > - u32 state = psci_get_domain_state(); > + struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data); > + u32 *states = data->psci_states; > + struct device *pd_dev = data->dev; > + bool runtime_pm = (pd_dev && data->rpm_state_id == idx); > + u32 state; Wonder if we can have separate psci_enter_idle_state for OSI mode so that all these runtime extra check can be reduced ? It will also make sure there's no additional latency for PC mode because of OSI. -- Regards, Sudeep