From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754343AbdDEGmq (ORCPT ); Wed, 5 Apr 2017 02:42:46 -0400 Received: from mx2.suse.de ([195.135.220.15]:44669 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753840AbdDEGmo (ORCPT ); Wed, 5 Apr 2017 02:42:44 -0400 Date: Wed, 5 Apr 2017 08:42:39 +0200 From: Michal Hocko To: Reza Arbab Cc: Mel Gorman , linux-mm@kvack.org, Andrew Morton , Vlastimil Babka , Andrea Arcangeli , Yasuaki Ishimatsu , Tang Chen , qiuxishi@huawei.com, Kani Toshimitsu , slaoub@gmail.com, Joonsoo Kim , Andi Kleen , Zhang Zhen , David Rientjes , Daniel Kiper , Igor Mammedov , Vitaly Kuznetsov , LKML , Chris Metcalf , Dan Williams , Heiko Carstens , Lai Jiangshan , Martin Schwidefsky Subject: Re: [PATCH 0/6] mm: make movable onlining suck less Message-ID: <20170405064239.GB6035@dhcp22.suse.cz> References: <20170403202337.GA12482@dhcp22.suse.cz> <20170403204213.rs7k2cvsnconel2z@arbab-laptop> <20170404072329.GA15132@dhcp22.suse.cz> <20170404073412.GC15132@dhcp22.suse.cz> <20170404082302.GE15132@dhcp22.suse.cz> <20170404160239.ftvuxklioo6zvuxl@arbab-laptop> <20170404164452.GQ15132@dhcp22.suse.cz> <20170404183012.a6biape5y7vu6cjm@arbab-laptop> <20170404194122.GS15132@dhcp22.suse.cz> <20170404214339.6o4c4uhwudyhzbbo@arbab-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170404214339.6o4c4uhwudyhzbbo@arbab-laptop> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 04-04-17 16:43:39, Reza Arbab wrote: > On Tue, Apr 04, 2017 at 09:41:22PM +0200, Michal Hocko wrote: > >On Tue 04-04-17 13:30:13, Reza Arbab wrote: > >>I think I found another edge case. You > >>get an oops when removing all of a node's memory: > >> > >>__nr_to_section > >>__pfn_to_section > >>find_biggest_section_pfn > >>shrink_pgdat_span > >>__remove_zone > >>__remove_section > >>__remove_pages > >>arch_remove_memory > >>remove_memory > > > >Is this something new or an old issue? I believe the state after the > >online should be the same as before. So if you onlined the full node > >then there shouldn't be any difference. Let me have a look... > > It's new. Without this patchset, I can repeatedly > add_memory()->online_movable->offline->remove_memory() all of a node's > memory. This is quite unexpected because the code obviously cannot handle the first memory section. Could you paste /proc/zoneinfo and grep . -r /sys/devices/system/memory/auto_online_blocks/memory*, after onlining for both patched and unpatched kernels? > >From 1b08ecef3e8ebcef585fe8f2b23155be54cce335 Mon Sep 17 00:00:00 2001 > >From: Michal Hocko > >Date: Tue, 4 Apr 2017 21:09:00 +0200 > >Subject: [PATCH] mm, hotplug: get rid of zone/node shrinking > > > ...%<... > >--- > >mm/memory_hotplug.c | 207 ---------------------------------------------------- > >1 file changed, 207 deletions(-) > > Okay, getting further. With this I can again repeatedly add and remove, but > now I'm seeing a weird variation of that earlier issue: > > 1. add_memory(), online_movable > /sys/devices/system/node/nodeX/memoryY symlinks are created. > > 2. offline, remove_memory() > The node is offlined, since all memory has been removed, so all of > /sys/devices/system/node/nodeX is gone. This is normal. > > 3. add_memory(), online_movable > The node is onlined, so /sys/devices/system/node/nodeX is recreated, > and the memory is added, but just like earlier in this email thread, > the memoryY links are not there. Could you add some printks to see why the sysfs creation failed please? -- Michal Hocko SUSE Labs 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 57E1A6B03A1 for ; Wed, 5 Apr 2017 02:42:45 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id u77so388604wrb.6 for ; Tue, 04 Apr 2017 23:42:45 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id l13si21972098wrl.51.2017.04.04.23.42.43 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 04 Apr 2017 23:42:44 -0700 (PDT) Date: Wed, 5 Apr 2017 08:42:39 +0200 From: Michal Hocko Subject: Re: [PATCH 0/6] mm: make movable onlining suck less Message-ID: <20170405064239.GB6035@dhcp22.suse.cz> References: <20170403202337.GA12482@dhcp22.suse.cz> <20170403204213.rs7k2cvsnconel2z@arbab-laptop> <20170404072329.GA15132@dhcp22.suse.cz> <20170404073412.GC15132@dhcp22.suse.cz> <20170404082302.GE15132@dhcp22.suse.cz> <20170404160239.ftvuxklioo6zvuxl@arbab-laptop> <20170404164452.GQ15132@dhcp22.suse.cz> <20170404183012.a6biape5y7vu6cjm@arbab-laptop> <20170404194122.GS15132@dhcp22.suse.cz> <20170404214339.6o4c4uhwudyhzbbo@arbab-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170404214339.6o4c4uhwudyhzbbo@arbab-laptop> Sender: owner-linux-mm@kvack.org List-ID: To: Reza Arbab Cc: Mel Gorman , linux-mm@kvack.org, Andrew Morton , Vlastimil Babka , Andrea Arcangeli , Yasuaki Ishimatsu , Tang Chen , qiuxishi@huawei.com, Kani Toshimitsu , slaoub@gmail.com, Joonsoo Kim , Andi Kleen , Zhang Zhen , David Rientjes , Daniel Kiper , Igor Mammedov , Vitaly Kuznetsov , LKML , Chris Metcalf , Dan Williams , Heiko Carstens , Lai Jiangshan , Martin Schwidefsky On Tue 04-04-17 16:43:39, Reza Arbab wrote: > On Tue, Apr 04, 2017 at 09:41:22PM +0200, Michal Hocko wrote: > >On Tue 04-04-17 13:30:13, Reza Arbab wrote: > >>I think I found another edge case. You > >>get an oops when removing all of a node's memory: > >> > >>__nr_to_section > >>__pfn_to_section > >>find_biggest_section_pfn > >>shrink_pgdat_span > >>__remove_zone > >>__remove_section > >>__remove_pages > >>arch_remove_memory > >>remove_memory > > > >Is this something new or an old issue? I believe the state after the > >online should be the same as before. So if you onlined the full node > >then there shouldn't be any difference. Let me have a look... > > It's new. Without this patchset, I can repeatedly > add_memory()->online_movable->offline->remove_memory() all of a node's > memory. This is quite unexpected because the code obviously cannot handle the first memory section. Could you paste /proc/zoneinfo and grep . -r /sys/devices/system/memory/auto_online_blocks/memory*, after onlining for both patched and unpatched kernels? > >From 1b08ecef3e8ebcef585fe8f2b23155be54cce335 Mon Sep 17 00:00:00 2001 > >From: Michal Hocko > >Date: Tue, 4 Apr 2017 21:09:00 +0200 > >Subject: [PATCH] mm, hotplug: get rid of zone/node shrinking > > > ...%<... > >--- > >mm/memory_hotplug.c | 207 ---------------------------------------------------- > >1 file changed, 207 deletions(-) > > Okay, getting further. With this I can again repeatedly add and remove, but > now I'm seeing a weird variation of that earlier issue: > > 1. add_memory(), online_movable > /sys/devices/system/node/nodeX/memoryY symlinks are created. > > 2. offline, remove_memory() > The node is offlined, since all memory has been removed, so all of > /sys/devices/system/node/nodeX is gone. This is normal. > > 3. add_memory(), online_movable > The node is onlined, so /sys/devices/system/node/nodeX is recreated, > and the memory is added, but just like earlier in this email thread, > the memoryY links are not there. Could you add some printks to see why the sysfs creation failed please? -- 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