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 5F0E5C10DCE for ; Wed, 18 Mar 2020 18:59:00 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B9BED20724 for ; Wed, 18 Mar 2020 18:58:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B9BED20724 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48jK811wQNzDqxj for ; Thu, 19 Mar 2020 05:58:57 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=softfail (domain owner discourages use of this host) smtp.mailfrom=linux.com (client-ip=3.19.106.255; helo=gentwo.org; envelope-from=cl@linux.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.com Received: from gentwo.org (gentwo.org [3.19.106.255]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48jK5z08tZzDqwl for ; Thu, 19 Mar 2020 05:57:10 +1100 (AEDT) Received: by gentwo.org (Postfix, from userid 1002) id 1FEAA3EF51; Wed, 18 Mar 2020 18:57:07 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by gentwo.org (Postfix) with ESMTP id 1DA593EF50; Wed, 18 Mar 2020 18:57:07 +0000 (UTC) Date: Wed, 18 Mar 2020 18:57:07 +0000 (UTC) From: Christopher Lameter X-X-Sender: cl@www.lameter.com To: Michal Hocko Subject: Re: [PATCH 3/3] mm/page_alloc: Keep memoryless cpuless node 0 offline In-Reply-To: <20200316085425.GB11482@dhcp22.suse.cz> Message-ID: References: <20200311110237.5731-1-srikar@linux.vnet.ibm.com> <20200311110237.5731-4-srikar@linux.vnet.ibm.com> <20200316085425.GB11482@dhcp22.suse.cz> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Srikar Dronamraju , Linus Torvalds , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mel Gorman , "Kirill A. Shutemov" , Andrew Morton , linuxppc-dev@lists.ozlabs.org, Vlastimil Babka Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, 16 Mar 2020, Michal Hocko wrote: > > We can dynamically number the nodes right? So just make sure that the > > firmware properly creates memory on node 0? > > Are you suggesting that the OS would renumber NUMA nodes coming > from FW just to satisfy node 0 existence? If yes then I believe this is > really a bad idea because it would make HW/LPAR configuration matching > to the resulting memory layout really hard to follow. NUMA nodes are created by the OS based on information provided by the firmware. Either the FW would need to ensure that a viable node 0 exists or the bootstrap arch code could setup things to the same effect.