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_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 E4AC7C2D0C2 for ; Thu, 2 Jan 2020 19:31:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B2B0D20848 for ; Thu, 2 Jan 2020 19:31:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728420AbgABTbC (ORCPT ); Thu, 2 Jan 2020 14:31:02 -0500 Received: from foss.arm.com ([217.140.110.172]:49508 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728135AbgABTbB (ORCPT ); Thu, 2 Jan 2020 14:31:01 -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 03130328; Thu, 2 Jan 2020 11:31:01 -0800 (PST) Received: from [192.168.0.7] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B9F863F703; Thu, 2 Jan 2020 11:30:59 -0800 (PST) Subject: Re: [PATCH] cpu-topology: warn if NUMA configurations conflicts with lower layer To: Valentin Schneider , "Zengtao (B)" , Sudeep Holla Cc: Linuxarm , Greg Kroah-Hartman , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , Morten Rasmussen 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> From: Dietmar Eggemann Message-ID: Date: Thu, 2 Jan 2020 20:30:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/01/2020 14:22, Valentin Schneider wrote: > On 02/01/2020 12:47, Zengtao (B) wrote: [...] >> From schedule view of point, lower level sched domain should be a subset of higher >> Level sched domain. >> > > Right, and that is checked when you have sched_debug on the cmdline > (or write 1 to /sys/kernel/debug/sched_debug & regenerate the sched domains) You should even get informed in case CONFIG_SCHED_DEBUG is not set. BUG: arch topology borken With CONFIG_SCHED_DEBUG (and a CPU removed from the cpu_mask (DIE level) on an Arm64 Juno board) you get extra information: BUG: arch topology borken the MC domain not a subset of the DIE domain > Now, I don't know how this plays out for the numa-in-package topologies like > the one suggested by Sudeep. x86 and AMD had to play some games to get > numa-in-package topologies working, see e.g. > > cebf15eb09a2 ("x86, sched: Add new topology for multi-NUMA-node CPUs") > Yeah, the reason why we need this change would be interesting. [...]