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 3EAB6C433EF for ; Fri, 20 May 2022 12:33:46 +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:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=HMfJEdfjbq/JFGf3t1fWp3wC6555dDbxMaLeCscOyJM=; b=4Mnus7s250aD59 ngAXUvC1Cf7aZ+i8Q9AZUnspzJVncJOdfykapoMCEulncFyHxDYGJy8J68jCpq/RCaEz1Sqvdss3U KK2KZqdDJlJQufeVzlic/Cc0omOTGWB2U9yJ4BDcUMwWsXTPR6HXEURzW0CEa0tmVwhpYjOSUtlOR Z1y2x3R8xWaJYBKrMX8QyPkynRtkb9oi8Z6Td/SVjF5rpBDlE4W2G5f2oLV19pGcVr5hUztMO0a31 vVaQ7oPckuLfxZHkJu5BBIF6pyU/NsPn2CdDQBEJdSsbfqgXIZChFif0lzkZCHhN6vyschRkg5++B Lct2PMtRGbi0GdjNebvA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ns1o4-00CL2w-Qx; Fri, 20 May 2022 12:32:36 +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 1ns1o1-00CL1j-CL; Fri, 20 May 2022 12:32:34 +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 4A7EF1477; Fri, 20 May 2022 05:32:32 -0700 (PDT) Received: from [172.29.1.145] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BC9513F718; Fri, 20 May 2022 05:32:29 -0700 (PDT) Message-ID: Date: Fri, 20 May 2022 14:32:19 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH v2 2/8] arch_topology: Set thread sibling cpumask only within the cluster Content-Language: en-US To: Sudeep Holla , Atish Patra , linux-kernel@vger.kernel.org Cc: Atish Patra , Vincent Guittot , Morten Rasmussen , Qing Wang , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, Rob Herring References: <20220518093325.2070336-1-sudeep.holla@arm.com> <20220518093325.2070336-3-sudeep.holla@arm.com> From: Dietmar Eggemann In-Reply-To: <20220518093325.2070336-3-sudeep.holla@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220520_053233_488970_3FE0D58C X-CRM114-Status: GOOD ( 10.52 ) 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 18/05/2022 11:33, Sudeep Holla wrote: > Currently the cluster identifier is not set on the DT based platforms. > The reset or default value is -1 for all the CPUs. Once we assign the > cluster identifier values correctly that imay result in getting the thread > siblings wrongs as the core identifiers can be same for 2 different CPUs > belonging to 2 different cluster. > > So, in order to get the thread sibling cpumasks correct, we need to > update them only if the cores they belong are in the same cluster within > the socket. Let us skip updation of the thread sibling cpumaks if the > cluster identifier doesn't match. So this issue should be there on ACPI systems as well then. Kunpeng920 and Ampere Altra don't have SMT, so very likely nobody has noticed this so far. [...] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel