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 2BEE8C433F5 for ; Fri, 20 May 2022 12:32:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349269AbiETMcj (ORCPT ); Fri, 20 May 2022 08:32:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52478 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243910AbiETMcd (ORCPT ); Fri, 20 May 2022 08:32:33 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7BD6B985A6 for ; Fri, 20 May 2022 05:32:32 -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 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> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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. [...]