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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6DCE1C43141 for ; Fri, 29 Jun 2018 10:29:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24CE5255AB for ; Fri, 29 Jun 2018 10:29:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24CE5255AB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754981AbeF2K3l (ORCPT ); Fri, 29 Jun 2018 06:29:41 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:59332 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754814AbeF2K3k (ORCPT ); Fri, 29 Jun 2018 06:29:40 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CFDCB18A; Fri, 29 Jun 2018 03:29:39 -0700 (PDT) Received: from e107155-lin (unknown [10.1.210.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 34C123F266; Fri, 29 Jun 2018 03:29:38 -0700 (PDT) Date: Fri, 29 Jun 2018 11:29:27 +0100 From: Sudeep Holla To: Andrew Jones Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, jeremy.linton@arm.com, ard.biesheuvel@linaro.org, shunyong.yang@hxt-semitech.com, yu.zheng@hxt-semitech.com, catalin.marinas@arm.com, will.deacon@arm.com Subject: Re: [PATCH] arm64: acpi: reenumerate topology ids Message-ID: <20180629102927.GA18043@e107155-lin> References: <20180628145128.10057-1-drjones@redhat.com> <20180628173243.obydzakh2stfs26w@kamzik.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180628173243.obydzakh2stfs26w@kamzik.brq.redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 28, 2018 at 07:32:43PM +0200, Andrew Jones wrote: > On Thu, Jun 28, 2018 at 05:30:51PM +0100, Sudeep Holla wrote: > > I am not sure if we can ever guarantee that DT and ACPI will get the > > same ids whatever counter we use as it depends on the order presented in > > the firmware(DT or ACPI). So I am not for generating ids for core and > > threads in that way. > > I don't believe we have to guarantee that the exact (package,core,thread) > triplet describing a PE with DT matches ACPI. We just need to guarantee > that each triplet we select properly puts a PE in the same group as its > peers. So, as long as we keep the grouping described by DT or ACPI, then > the (package,core,thread) IDs assigned are pretty arbitrary. > If that's the requirement, we already do that. The IDs are just too arbitrary :) > I could change the commit message to state we can generate IDs *like* > DT does (i.e. with counters), even if they may not result in identical > triplet to PE mappings. > Why we need to make it *like DT* ? > > > > So I would like to keep it simple and just have this counters for > > package ids as demonstrated in Shunyong's patch. > > > > If we don't also handle cores when there are threads, then the cores > will also end up having weird IDs. > Yes, but if PPTT says it has valid ID, I would prefer that over DT like generated. -- Regards, Sudeep