From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id E4EB46B02FD for ; Thu, 15 Jun 2017 04:16:16 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id y19so1796683wrc.8 for ; Thu, 15 Jun 2017 01:16:16 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id u50si2582400wrc.328.2017.06.15.01.16.15 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 15 Jun 2017 01:16:15 -0700 (PDT) Date: Thu, 15 Jun 2017 10:16:11 +0200 From: Michal Hocko Subject: Re: [PATCH] mm, memory_hotplug: support movable_node for hotplugable nodes Message-ID: <20170615081611.GD1486@dhcp22.suse.cz> References: <20170608122318.31598-1-mhocko@kernel.org> <20170612042832.GA7429@WeideMBP.lan> <20170612064502.GD4145@dhcp22.suse.cz> <20170615031354.GC16833@WeideMacBook-Pro.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170615031354.GC16833@WeideMacBook-Pro.local> Sender: owner-linux-mm@kvack.org List-ID: To: Wei Yang Cc: Andrew Morton , linux-mm@kvack.org, Mel Gorman , Vlastimil Babka , Andrea Arcangeli , Reza Arbab , Yasuaki Ishimatsu , qiuxishi@huawei.com, Kani Toshimitsu , slaoub@gmail.com, Joonsoo Kim , Andi Kleen , David Rientjes , Daniel Kiper , Igor Mammedov , Vitaly Kuznetsov , LKML On Thu 15-06-17 11:13:54, Wei Yang wrote: > On Mon, Jun 12, 2017 at 08:45:02AM +0200, Michal Hocko wrote: > >On Mon 12-06-17 12:28:32, Wei Yang wrote: > >> On Thu, Jun 08, 2017 at 02:23:18PM +0200, Michal Hocko wrote: > >> >From: Michal Hocko > >> > > >> >movable_node kernel parameter allows to make hotplugable NUMA > >> >nodes to put all the hotplugable memory into movable zone which > >> >allows more or less reliable memory hotremove. At least this > >> >is the case for the NUMA nodes present during the boot (see > >> >find_zone_movable_pfns_for_nodes). > >> > > >> > >> When movable_node is enabled, we would have overlapped zones, right? > > > >It won't based on this patch. See movable_pfn_range > > > > Ok, I went through the code and here maybe a question not that close related > to this patch. Please start a new thread with unrelated questions > I did some experiment with qemu+kvm and see this. > > Guest config: 8G RAM, 2 nodes with 4G on each > Guest kernel: 4.11 > Guest kernel command: kernelcore=1G > > The log message in kernel is: > > [ 0.000000] Zone ranges: > [ 0.000000] DMA [mem 0x0000000000001000-0x0000000000ffffff] > [ 0.000000] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] > [ 0.000000] Normal [mem 0x0000000100000000-0x000000023fffffff] > [ 0.000000] Movable zone start for each node > [ 0.000000] Node 0: 0x0000000100000000 > [ 0.000000] Node 1: 0x0000000140000000 > > We see on node 2, ZONE_NORMAL overlap with ZONE_MOVABLE. > [0x0000000140000000 - 0x000000023fffffff] belongs to both ZONE. Not really. The above output is just confusing a bit. Zone ranges print arch_zone_{lowest,highest}_possible_pfn range while the Movable zone is excluded from that in adjust_zone_range_for_zone_movable -- Michal Hocko 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