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 6FC3CC10DCE for ; Sun, 15 Mar 2020 14:22:00 +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 C2255205C9 for ; Sun, 15 Mar 2020 14:21:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C2255205C9 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 48gM7m5t1BzDqP1 for ; Mon, 16 Mar 2020 01:21:56 +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 48gM5h60JbzDqN3 for ; Mon, 16 Mar 2020 01:20:08 +1100 (AEDT) Received: by gentwo.org (Postfix, from userid 1002) id 1BDDF3F7A9; Sun, 15 Mar 2020 14:20:05 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by gentwo.org (Postfix) with ESMTP id 19C4C3F6EC; Sun, 15 Mar 2020 14:20:05 +0000 (UTC) Date: Sun, 15 Mar 2020 14:20:05 +0000 (UTC) From: Christopher Lameter X-X-Sender: cl@www.lameter.com To: Srikar Dronamraju Subject: Re: [PATCH 3/3] mm/page_alloc: Keep memoryless cpuless node 0 offline In-Reply-To: <20200311110237.5731-4-srikar@linux.vnet.ibm.com> Message-ID: References: <20200311110237.5731-1-srikar@linux.vnet.ibm.com> <20200311110237.5731-4-srikar@linux.vnet.ibm.com> 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: Michal Hocko , 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 Wed, 11 Mar 2020, Srikar Dronamraju wrote: > Currently Linux kernel with CONFIG_NUMA on a system with multiple > possible nodes, marks node 0 as online at boot. However in practice, > there are systems which have node 0 as memoryless and cpuless. Would it not be better and simpler to require that node 0 always has memory (and processors)? A mininum operational set? We can dynamically number the nodes right? So just make sure that the firmware properly creates memory on node 0?