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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 267F0CE79AC for ; Wed, 20 Sep 2023 09:24:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8DC036B0139; Wed, 20 Sep 2023 05:24:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 88B816B013A; Wed, 20 Sep 2023 05:24:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 77AE66B013B; Wed, 20 Sep 2023 05:24:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 657E16B0139 for ; Wed, 20 Sep 2023 05:24:10 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 205CDB34E6 for ; Wed, 20 Sep 2023 09:24:10 +0000 (UTC) X-FDA: 81256439460.25.2FEE370 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf20.hostedemail.com (Postfix) with ESMTP id EB59E1C0005 for ; Wed, 20 Sep 2023 09:24:07 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf20.hostedemail.com: domain of sudeep.holla@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=sudeep.holla@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1695201848; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3AQ4u5gKVFWHAggiWCOYdkgxl/vl4naNMDSuOe19NDg=; b=XUlBczwFtGePyQnAuaoeEFHjA5e1wF7eSiWe3s5LSY6HF1ClDCiepXS3112fiz7qQekc73 kbdewIHlwtHtLud7iMEYNrPoyMRDTm/eTJAcn7qeqJsQo38G+BYWTJA5Zi70h8nF5cx8dw ivgifJppTYEEmY3HthorF/fZUUb6FYk= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf20.hostedemail.com: domain of sudeep.holla@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=sudeep.holla@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1695201848; a=rsa-sha256; cv=none; b=8ZbUXVa4K7deQNtAx0rBow7J9zQbZRFOFPJQwD+gddCzRNlsBqVtrYBjlFm06LyffRPr2j mjCUpgqjOvznbDtWuu3nnucedaFhwrxqqXcdZLgzwB52BPPoBXrHeAMs/s7QI4+ngKtAw0 xTToZh6O1BKW9/KnS7eZ6zScNzy7TTM= 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 3A5031FB; Wed, 20 Sep 2023 02:24:44 -0700 (PDT) Received: from bogus (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 131FA3F5A1; Wed, 20 Sep 2023 02:24:04 -0700 (PDT) Date: Wed, 20 Sep 2023 10:24:02 +0100 From: Sudeep Holla To: Huang Ying Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Sudeep Holla , Arjan Van De Ven , Andrew Morton , Mel Gorman , Vlastimil Babka , David Hildenbrand , Johannes Weiner , Dave Hansen , Michal Hocko , Pavel Tatashin , Matthew Wilcox , Christoph Lameter Subject: Re: [PATCH 02/10] cacheinfo: calculate per-CPU data cache size Message-ID: <20230920092402.pvqju4knnqkzqfiq@bogus> References: <20230920061856.257597-1-ying.huang@intel.com> <20230920061856.257597-3-ying.huang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230920061856.257597-3-ying.huang@intel.com> X-Rspamd-Queue-Id: EB59E1C0005 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: 6u6enet9bz4qsa7e6mr1krbyr56hd3bk X-HE-Tag: 1695201847-101120 X-HE-Meta: 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 BR95txiT 1kV1cjlcsXVYh3Im97sKkRYx4OvTUlfBSaQh+dxWGeNJQAVeArCH81gnx+2OqC++aNwpa7cU5l5nBS6zRqGwxmaOldDHnr/Vh1Nyni0aaPALbzyKE6IUm0ueOMPS6iFH990+sREv9THmwUla5kze5jd2Jmb0EBgP03NoTSy/sWBjPFMOW20PvC4y0wQr3FgAU4eolqwceI7iOntZy+hrSgqHUyw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Sep 20, 2023 at 02:18:48PM +0800, Huang Ying wrote: > Per-CPU data cache size is useful information. For example, it can be > used to determine per-CPU cache size. So, in this patch, the data > cache size for each CPU is calculated via data_cache_size / > shared_cpu_weight. > > A brute-force algorithm to iterate all online CPUs is used to avoid > to allocate an extra cpumask, especially in offline callback. > You have not mentioned who will use this information ? Looking at the change, it is not exposed to the user-space. Also I see this is actually part of the series [1]. Is this info used in any of those patches ? Can you point me to the same ? Not all architecture use cacheinfo yet. How will the mm changes affect those platforms ? -- Regards, Sudeep [1] https://lore.kernel.org/all/20230920061856.257597-1-ying.huang@intel.com/