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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 32636C4332E for ; Thu, 19 Mar 2020 07:44:43 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0E6232071C for ; Thu, 19 Mar 2020 07:44:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E6232071C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 771876B0003; Thu, 19 Mar 2020 03:44:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 721026B0005; Thu, 19 Mar 2020 03:44:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 636246B0006; Thu, 19 Mar 2020 03:44:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0200.hostedemail.com [216.40.44.200]) by kanga.kvack.org (Postfix) with ESMTP id 4A0276B0003 for ; Thu, 19 Mar 2020 03:44:42 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id E9BA78245571 for ; Thu, 19 Mar 2020 07:44:41 +0000 (UTC) X-FDA: 76611324762.23.mind74_804b7a6e78d4e X-HE-Tag: mind74_804b7a6e78d4e X-Filterd-Recvd-Size: 2282 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Thu, 19 Mar 2020 07:44:41 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 0E7E9AE3A; Thu, 19 Mar 2020 07:44:38 +0000 (UTC) Date: Thu, 19 Mar 2020 08:44:36 +0100 From: Michal Hocko To: Christopher Lameter Cc: Srikar Dronamraju , Andrew Morton , linux-mm@kvack.org, Mel Gorman , Michael Ellerman , Sachin Sant , linuxppc-dev@lists.ozlabs.org, Joonsoo Kim , Kirill Tkhai , Vlastimil Babka , Bharata B Rao , Nathan Lynch Subject: Re: [PATCH v2 3/4] mm: Implement reset_numa_mem Message-ID: <20200319074436.GX21362@dhcp22.suse.cz> References: <20200318072810.9735-1-srikar@linux.vnet.ibm.com> <20200318072810.9735-4-srikar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed 18-03-20 19:20:41, Cristopher Lameter wrote: > On Wed, 18 Mar 2020, Srikar Dronamraju wrote: > > > For a memoryless or offline nodes, node_numa_mem refers to a N_MEMORY > > fallback node. Currently kernel has an API set_numa_mem that sets > > node_numa_mem for memoryless node. However this API cannot be used for > > offline nodes. Hence all offline nodes will have their node_numa_mem set > > to 0. However systems can themselves have node 0 as offline i.e > > That is a significant change to the basic assumptions for memory less > nodes. Node 0 needed to have memory and processors. Not sure what else > may break. This assumption is simply incorrect. There many examples but just one from top of my head 3e8589963773 ("memcg: make it work on sparse non-0-node systems"). We simply have to forget that some nodes are special. -- Michal Hocko SUSE Labs