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 BAB1DC433EF for ; Tue, 26 Apr 2022 06:42:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245759AbiDZGoO (ORCPT ); Tue, 26 Apr 2022 02:44:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245641AbiDZGoG (ORCPT ); Tue, 26 Apr 2022 02:44:06 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 097701B784 for ; Mon, 25 Apr 2022 23:40:59 -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 C686623A; Mon, 25 Apr 2022 23:40:58 -0700 (PDT) Received: from bogus (unknown [10.57.11.83]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8CC343F5A1; Mon, 25 Apr 2022 23:40:57 -0700 (PDT) Date: Tue, 26 Apr 2022 07:40:53 +0100 From: Sudeep Holla To: =?utf-8?B?546L5pOO?= Cc: Catalin Marinas , Will Deacon , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "vincent.guittot@linaro.org" , "peterz@infradead.org" , "dietmar.eggemann@arm.com" Subject: Re: [PATCH V2] arm64: add SCHED_CLUSTER's dependency on ACPI Message-ID: <20220426064053.h4rwvcdvmwxj2hmt@bogus> References: <1650855303-91388-1-git-send-email-wangqing@vivo.com> <20220425100635.ig4dxvlflglfagpx@bogus> <20220425165946.qb6xilgmjahdh4pa@bogus> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 26, 2022 at 02:23:25AM +0000, 王擎 wrote: > > >> > >> >> From: Wang Qing > >> >> > >> >> cluster sched_domain configured by cpu_topology[].cluster_sibling, > >> >> which is set by cluster_id, cluster_id can only get from ACPI. > >> >> > >> >> If the system does not enable ACPI, cluster_id is always -1, even enable > >> >> SCHED_CLUSTER is invalid, this is misleading. > >> >> > >> >> So we add SCHED_CLUSTER's dependency on ACPI here. > >> >> > >> > > >> >Any reason why this can't be extended to support DT based systems via > >> >cpu-map in the device tree. IMO we almost have everything w.r.t topology > >> >in DT and no reason to deviate this feature between ACPI and DT. > >> > > >> That's the problem, we parse out "cluster" info according to the > >> description in cpu-map, but do assign it to package_id, which used to > >> configure the MC sched domain, not cluster sched domain. > >> > > > >Right, we haven't updated the code after updating the bindings to match > >ACPI sockets which are the physical package boundaries. Clusters are not > >the physical boundaries and the current topology code is not 100% aligned > >with the bindings after Commit 849b384f92bc ("Documentation: DT: arm: add > >support for sockets defining package boundaries") > > I see, but this commit is a long time ago, why hasn't it been used widely. > Maybe I can help about it if you need. > I assume no one cared or had a requirement for the same. -- Regards, Sudeep