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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 489D3EED620 for ; Fri, 15 Sep 2023 17:17:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235529AbjIORR0 (ORCPT ); Fri, 15 Sep 2023 13:17:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234978AbjIORQv (ORCPT ); Fri, 15 Sep 2023 13:16:51 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id DAFA883 for ; Fri, 15 Sep 2023 10:16:46 -0700 (PDT) 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 DE8EC1FB; Fri, 15 Sep 2023 10:17:23 -0700 (PDT) Received: from [10.1.197.60] (eglon.cambridge.arm.com [10.1.197.60]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F08143F5A1; Fri, 15 Sep 2023 10:16:44 -0700 (PDT) Message-ID: <6682c765-9d7f-dd21-af85-e83cee435a89@arm.com> Date: Fri, 15 Sep 2023 18:16:43 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [EXT] Re: resctrl2 - status Content-Language: en-GB To: Jonathan Cameron , Amit Singh Tomar Cc: Reinette Chatre , "Luck, Tony" , "Yu, Fenghua" , George Cherian , "robh@kernel.org" , "peternewman@google.com" , Drew Fustini , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" References: <35f05064-a412-ad29-5352-277fb147bbc4@intel.com> <20230829112321.00002b55@Huawei.com> <20230830114731.00003590@Huawei.com> From: James Morse In-Reply-To: <20230830114731.00003590@Huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi guys, On 30/08/2023 11:47, Jonathan Cameron wrote: > On Tue, 29 Aug 2023 17:18:53 +0000 > Amit Singh Tomar wrote: >> From: Jonathan Cameron >> James probably also has views on this, but I wouldn't expect userspace to go anywhere near ACPI parsing. I agree wholeheartedly! Parsing the ACPI tables also wouldn't work: the firmware tables describe where the MPAM hardware is, but the features that are supported are described by the hardware, then grouped to find the common features we can make use of. >> If the description of what MPAM features are supported (before resctrl is running) is necessary, then we >> should add it to the existing description of the various caches etc. Maybe somewhere in >> /sys/bus/node/devices/nodeX/cpuY/cache/indexZ/ >> for the caches >> and >> /sys/bus/node/devices/nodeX for the DRAM controllers. >> [>>] Or may be all the MPAM features list is unified at one place, something like this ? >> https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/commit/?h=mpam/snapshot/v6.5-rc1&id=c32874cd1d68241c481a9d0c32c8c65d019c247e > > Fine for debug, not for generic tooling. Yeah, this is really just for folk reporting bugs to me so we can work out what their firmware table described, and what the driver found. Thanks, James