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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 31090C433F5 for ; Wed, 9 Mar 2022 09:55:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=kGU2ESiO1//7fs2x4bBbiKNwZET0r2nzwfSy9ROn13g=; b=m46TnRF+iu9SNM StxbVR2Z4EN986221i68QJg9IFav0BOdo7z/vT2uWOXJ9MlJw+UeWcE/cVqhjBr82Le/hyPs5kzbu e5MMgEMStNc/4x7d6/yMCWiJDum0yaEj1roWtgJCxvOUdiWE1a/aiYRrsuB54E4Skj4L1uiLlFeFa uD4UgSytQxDVZfFzLpHQ7FsMJWpiaRmBbA00Fbp8MuwDEjk8mnJyO0q1/9iQ3S5fn4c+UEJ0/EEXF xNF2do7lnKZ0SrA79SoD/IsO/YJC8+iitXUwxmMdKGUxJZxv1yYCG7tYtTRlCaa16YbdtzmaKT0Yv NiAsfH1Uc5NJD3sjXfJw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRt1e-0080LC-P6; Wed, 09 Mar 2022 09:54:35 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRt1a-0080Jf-Ui for linux-arm-kernel@lists.infradead.org; Wed, 09 Mar 2022 09:54:32 +0000 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 554C31650; Wed, 9 Mar 2022 01:54:28 -0800 (PST) Received: from bogus (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 720D43FA4D; Wed, 9 Mar 2022 01:54:26 -0800 (PST) Date: Wed, 9 Mar 2022 09:54:24 +0000 From: Sudeep Holla To: Ionela Voinescu Cc: "Rafael J . Wysocki" , Sudeep Holla , Thomas Gleixner , Ingo Molnar , Giovanni Gherdovich , Catalin Marinas , Will Deacon , Valentin Schneider , Dietmar Eggemann , Sean Kelley , Pierre Gondois , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 2/3] arch_topology: obtain cpu capacity using information from CPPC Message-ID: References: <20220302180913.13229-1-ionela.voinescu@arm.com> <20220302180913.13229-3-ionela.voinescu@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220302180913.13229-3-ionela.voinescu@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220309_015431_079252_2F28ECB0 X-CRM114-Status: GOOD ( 16.05 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Mar 02, 2022 at 06:09:12PM +0000, Ionela Voinescu wrote: > Define topology_init_cpu_capacity_cppc() to use highest performance > values from _CPC objects to obtain and set maximum capacity information > for each CPU. acpi_cppc_processor_probe() is a good point at which to > trigger the initialization of CPU (u-arch) capacity values, as at this > point the highest performance values can be obtained from each CPU's > _CPC objects. Architectures can therefore use this functionality > through arch_init_invariance_cppc(). > > The performance scale used by CPPC is a unified scale for all CPUs in > the system. Therefore, by obtaining the raw highest performance values > from the _CPC objects, and normalizing them on the [0, 1024] capacity > scale, used by the task scheduler, we obtain the CPU capacity of each > CPU. > > While an ACPI Notify(0x85) could alert about a change in the highest > performance value, which should in turn retrigger the CPU capacity > computations, this notification is not currently handled by the ACPI > processor driver. When supported, a call to arch_init_invariance_cppc() > would perform the update. > > Signed-off-by: Ionela Voinescu > Tested-by: Valentin Schneider > Cc: Sudeep Holla Looks good to me. FWIW, Acked-by: Sudeep Holla -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel