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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 903EBC433DF for ; Wed, 3 Jun 2020 07:04:39 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 54CBD20674 for ; Wed, 3 Jun 2020 07:04:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 54CBD20674 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D94E66E05A; Wed, 3 Jun 2020 07:04:29 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id C399F6E169 for ; Tue, 2 Jun 2020 11:31:38 +0000 (UTC) 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 B08A931B; Tue, 2 Jun 2020 04:31:37 -0700 (PDT) Received: from [10.37.12.87] (unknown [10.37.12.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 54B5E3F52E; Tue, 2 Jun 2020 04:31:27 -0700 (PDT) Subject: Re: [PATCH v8 4/8] PM / EM: add support for other devices than CPUs in Energy Model To: Daniel Lezcano , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-omap@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-imx@nxp.com References: <20200527095854.21714-1-lukasz.luba@arm.com> <20200527095854.21714-5-lukasz.luba@arm.com> From: Lukasz Luba Message-ID: <7201e161-6952-6e28-4036-bd0f0353ec30@arm.com> Date: Tue, 2 Jun 2020 12:31:25 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Mailman-Approved-At: Wed, 03 Jun 2020 07:04:29 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nm@ti.com, juri.lelli@redhat.com, peterz@infradead.org, viresh.kumar@linaro.org, liviu.dudau@arm.com, bjorn.andersson@linaro.org, bsegall@google.com, mka@chromium.org, amit.kucheria@verdurent.com, lorenzo.pieralisi@arm.com, vincent.guittot@linaro.org, khilman@kernel.org, steven.price@arm.com, cw00.choi@samsung.com, mingo@redhat.com, mgorman@suse.de, rui.zhang@intel.com, alyssa.rosenzweig@collabora.com, orjan.eide@arm.com, b.zolnierkie@samsung.com, s.hauer@pengutronix.de, rostedt@goodmis.org, matthias.bgg@gmail.com, Dietmar.Eggemann@arm.com, airlied@linux.ie, tomeu.vizoso@collabora.com, qperret@google.com, sboyd@kernel.org, rdunlap@infradead.org, rjw@rjwysocki.net, agross@kernel.org, kernel@pengutronix.de, sudeep.holla@arm.com, patrick.bellasi@matbug.net, shawnguo@kernel.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Daniel, On 6/1/20 10:44 PM, Daniel Lezcano wrote: > On 27/05/2020 11:58, Lukasz Luba wrote: >> Add support for other devices than CPUs. The registration function >> does not require a valid cpumask pointer and is ready to handle new >> devices. Some of the internal structures has been reorganized in order to >> keep consistent view (like removing per_cpu pd pointers). >> >> Signed-off-by: Lukasz Luba >> --- > > [ ... ] > >> } >> EXPORT_SYMBOL_GPL(em_register_perf_domain); >> + >> +/** >> + * em_dev_unregister_perf_domain() - Unregister Energy Model (EM) for a device >> + * @dev : Device for which the EM is registered >> + * >> + * Try to unregister the EM for the specified device (but not a CPU). >> + */ >> +void em_dev_unregister_perf_domain(struct device *dev) >> +{ >> + if (IS_ERR_OR_NULL(dev) || !dev->em_pd) >> + return; >> + >> + if (_is_cpu_device(dev)) >> + return; >> + >> + mutex_lock(&em_pd_mutex); > > Is the mutex really needed? I just wanted to align this unregister code with register. Since there is debugfs dir lookup and the device's EM existence checks I thought it wouldn't harm just to lock for a while and make sure the registration path is not used. These two paths shouldn't affect each other, but with modules loading/unloading I wanted to play safe. I can change it maybe to just dmb() and the end of the function if it's a big performance problem in this unloading path. What do you think? > > If this function is called that means there is no more user of the > em_pd, no? True, that EM users should already be unregistered i.e. thermal cooling. > >> + em_debug_remove_pd(dev); >> + >> + kfree(dev->em_pd->table); >> + kfree(dev->em_pd); >> + dev->em_pd = NULL; >> + mutex_unlock(&em_pd_mutex); >> +} >> +EXPORT_SYMBOL_GPL(em_dev_unregister_perf_domain); >> > > Thank you for reviewing this. Regards, Lukasz _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel