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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 8A5F6C32771 for ; Thu, 9 Jan 2020 10:52:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 66A52206ED for ; Thu, 9 Jan 2020 10:52:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729608AbgAIKwd (ORCPT ); Thu, 9 Jan 2020 05:52:33 -0500 Received: from foss.arm.com ([217.140.110.172]:56962 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729287AbgAIKwc (ORCPT ); Thu, 9 Jan 2020 05:52:32 -0500 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 E3F8831B; Thu, 9 Jan 2020 02:52:31 -0800 (PST) Received: from e105550-lin.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E472C3F703; Thu, 9 Jan 2020 02:52:30 -0800 (PST) Date: Thu, 9 Jan 2020 10:52:28 +0000 From: Morten Rasmussen To: Valentin Schneider Cc: "Zengtao (B)" , Sudeep Holla , Linuxarm , Greg Kroah-Hartman , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] cpu-topology: warn if NUMA configurations conflicts with lower layer Message-ID: <20200109105228.GB10914@e105550-lin.cambridge.arm.com> References: <1577088979-8545-1-git-send-email-prime.zeng@hisilicon.com> <20191231164051.GA4864@bogus> <678F3D1BB717D949B966B68EAEB446ED340AE1D3@dggemm526-mbx.china.huawei.com> <20200102112955.GC4864@bogus> <678F3D1BB717D949B966B68EAEB446ED340AEB67@dggemm526-mbx.china.huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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, Jan 02, 2020 at 01:22:19PM +0000, Valentin Schneider wrote: > On 02/01/2020 12:47, Zengtao (B) wrote: > >> > >> As I said, wrong configurations need to be detected when generating > >> DT/ACPI if possible. The above will print warning on systems with NUMA > >> within package. > >> > >> NUMA: 0-7, 8-15 > >> core_siblings: 0-15 > >> > >> The above is the example where the die has 16 CPUs and 2 NUMA nodes > >> within a package, your change throws error to the above config which is > >> wrong. > >> > > From your example, the core 7 and core 8 has got different LLC but the same Low > > Level cache? > > AFAIA what matters here is memory controllers, less so LLCs. Cores within > a single die could have private LLCs and separate memory controllers, or > shared LLC and separate memory controllers. Don't confuse cache boundaries, packages and nodes :-) core_siblings are cpus in the same package and doesn't say anything about cache boundaries. It is not given that there is sched_domain that matches the core_sibling span. The MC sched_domain is supposed to match the LLC span which might different for core_siblings. So the about example should be valid for a NUMA-in-package system with one package containing two nodes. Morten