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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 14093C433DF for ; Fri, 7 Aug 2020 04:32:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A62C322CAF for ; Fri, 7 Aug 2020 04:32:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="PivBxqhp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A62C322CAF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1390F6B0003; Fri, 7 Aug 2020 00:32:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0C4036B0005; Fri, 7 Aug 2020 00:32:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EA6486B0007; Fri, 7 Aug 2020 00:32:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0060.hostedemail.com [216.40.44.60]) by kanga.kvack.org (Postfix) with ESMTP id D011F6B0003 for ; Fri, 7 Aug 2020 00:32:14 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 621A23634 for ; Fri, 7 Aug 2020 04:32:14 +0000 (UTC) X-FDA: 77122500588.08.party71_0f015d626fbd Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id 2616E1819E766 for ; Fri, 7 Aug 2020 04:32:14 +0000 (UTC) X-HE-Tag: party71_0f015d626fbd X-Filterd-Recvd-Size: 3342 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Fri, 7 Aug 2020 04:32:13 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 14E3621744; Fri, 7 Aug 2020 04:32:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596774732; bh=Fz8huZnhhkLwSX05aWzvKoou0vXMR2d8SOky+EI3hfo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=PivBxqhpKW9l29vGnuwJI6ZUtWS9wpMsCHjc3KbEXRi35qRfLW8Eq2I51dbr5v5Vp y3VzXxjiHFgoz6S8sgt5uLnP49+A9eUa4zcnMZ/AqMf9nlm3iLtG2OtSbKmVazwCkQ qIQ0b2z/plBFKHgHrgl8VXcnraRUyFBRX5ksLUqQ= Date: Thu, 6 Aug 2020 21:32:11 -0700 From: Andrew Morton To: Srikar Dronamraju Cc: Michal Hocko , Michal Such?nek , David Hildenbrand , Gautham R Shenoy , Linus Torvalds , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Satheesh Rajendran , Mel Gorman , "Kirill A. Shutemov" , linuxppc-dev@lists.ozlabs.org, Christopher Lameter , Vlastimil Babka , Andi Kleen Subject: Re: [PATCH v5 3/3] mm/page_alloc: Keep memoryless cpuless node 0 offline Message-Id: <20200806213211.6a6a56037fe771836e5abbe9@linux-foundation.org> In-Reply-To: <20200703125823.GA26243@linux.vnet.ibm.com> References: <20200701084200.GN2369@dhcp22.suse.cz> <20200701100442.GB17918@linux.vnet.ibm.com> <184102af-ecf2-c834-db46-173ab2e66f51@redhat.com> <20200701110145.GC17918@linux.vnet.ibm.com> <0468f965-8762-76a3-93de-3987cf859927@redhat.com> <12945273-d788-710d-e8d7-974966529c7d@redhat.com> <20200701122110.GT2369@dhcp22.suse.cz> <20200703091001.GJ21462@kitsune.suse.cz> <20200703092414.GR18446@dhcp22.suse.cz> <20200703105944.GS18446@dhcp22.suse.cz> <20200703125823.GA26243@linux.vnet.ibm.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 2616E1819E766 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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 Fri, 3 Jul 2020 18:28:23 +0530 Srikar Dronamraju wrote: > > The memory hotplug changes that somehow because you can hotremove numa > > nodes and therefore make the nodemask sparse but that is not a common > > case. I am not sure what would happen if a completely new node was added > > and its corresponding node was already used by the renumbered one > > though. It would likely conflate the two I am afraid. But I am not sure > > this is really possible with x86 and a lack of a bug report would > > suggest that nobody is doing that at least. > > > > JFYI, > Satheesh copied in this mailchain had opened a bug a year on crash with vcpu > hotplug on memoryless node. > > https://bugzilla.kernel.org/show_bug.cgi?id=202187 So... do we merge this patch or not? Seems that the overall view is "risky but nobody is likely to do anything better any time soon"?