From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id 58BAC6B027A for ; Thu, 10 Nov 2016 04:07:24 -0500 (EST) Received: by mail-wm0-f70.google.com with SMTP id m203so5391523wma.2 for ; Thu, 10 Nov 2016 01:07:24 -0800 (PST) Received: from outbound-smtp04.blacknight.com (outbound-smtp04.blacknight.com. [81.17.249.35]) by mx.google.com with ESMTPS id yn1si3994106wjc.162.2016.11.10.01.07.23 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 10 Nov 2016 01:07:23 -0800 (PST) Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp04.blacknight.com (Postfix) with ESMTPS id CC1499922D for ; Thu, 10 Nov 2016 09:07:22 +0000 (UTC) Date: Thu, 10 Nov 2016 09:07:22 +0000 From: Mel Gorman Subject: Re: [RFC] mem-hotplug: shall we skip unmovable node when doing numa balance? Message-ID: <20161110090722.yyznotwqqxz3v6uo@techsingularity.net> References: <582157E5.8000106@huawei.com> <20161109115827.GD3614@techsingularity.net> <5823E6AF.8040600@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <5823E6AF.8040600@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: Xishi Qiu Cc: Vlastimil Babka , Andrew Morton , Tang Chen , Linux MM , LKML , "robert.liu@huawei.com" On Thu, Nov 10, 2016 at 11:17:03AM +0800, Xishi Qiu wrote: > On 2016/11/9 19:58, Mel Gorman wrote: > > > On Tue, Nov 08, 2016 at 12:43:17PM +0800, Xishi Qiu wrote: > >> On mem-hotplug system, there is a problem, please see the following case. > >> > >> memtester xxG, the memory will be alloced on a movable node. And after numa > >> balancing, the memory may be migrated to the other node, it may be a unmovable > >> node. This will reduce the free memory of the unmovable node, and may be oom > >> later. > >> > > > > How would it OOM later? It's movable memmory that is moving via > > automatic NUMA balancing so at the very least it can be reclaimed. If > > the memory is mlocked or unable to migrate then it's irrelevant if > > automatic balancing put it there. > > > > memtester will mlock the memory, so we can not reclaim, then maybe oom, right? > So let the manager set some numa policies to prevent the above case, right? > Deal with it using policies. -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org