From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754329AbdDMOFY (ORCPT ); Thu, 13 Apr 2017 10:05:24 -0400 Received: from mx2.suse.de ([195.135.220.15]:54103 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753433AbdDMOFU (ORCPT ); Thu, 13 Apr 2017 10:05:20 -0400 Subject: Re: [PATCH 5/9] mm, memory_hotplug: split up register_one_node To: Michal Hocko , linux-mm@kvack.org References: <20170410110351.12215-1-mhocko@kernel.org> <20170410110351.12215-6-mhocko@kernel.org> Cc: Andrew Morton , Mel Gorman , Andrea Arcangeli , Jerome Glisse , 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 , Michal Hocko From: Vlastimil Babka Message-ID: Date: Thu, 13 Apr 2017 16:05:17 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170410110351.12215-6-mhocko@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/10/2017 01:03 PM, Michal Hocko wrote: > From: Michal Hocko > > Memory hotplug (add_memory_resource) has to reinitialize node > infrastructure if the node is offline (one which went through the > complete add_memory(); remove_memory() cycle). That involves node > registration to the kobj infrastructure (register_node), the proper > association with cpus (register_cpu_under_node) and finally creation of > node<->memblock symlinks (link_mem_sections). > > The last part requires to know node_start_pfn and node_spanned_pages > which we currently have but a leter patch will postpone this > initialization to the onlining phase which happens later. In fact we do > not need to rely on the early pgdat initialization even now because the > currently hot added pfn range is currently known. > > Split register_one_node into core which does all the common work for > the boot time NUMA initialization and the hotplug (__register_one_node). > register_one_node keeps the full initialization while hotplug calls > __register_one_node and manually calls link_mem_sections for the proper > range. > > This shouldn't introduce any functional change. > > Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka nit: > @@ -1387,7 +1387,22 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) > node_set_online(nid); > > if (new_node) { > - ret = register_one_node(nid); > + unsigned long start_pfn = start >> PAGE_SHIFT; > + unsigned long nr_pages = size >> PAGE_SHIFT; > + > + ret = __register_one_node(nid); > + if (ret) > + goto register_fail; > + > + /* > + * link memory sections under this node. This is already > + * done when creatig memory section in register_new_memory > + * but that depends to have the node registered so offline > + * nodes have to go through register_node. > + * TODO clean up this mess. Is this a work-in-progress or final TODO? :) > + */ > + ret = link_mem_sections(nid, start_pfn, nr_pages); > +register_fail: > /* > * If sysfs file of new node can't create, cpu on the node > * can't be hot-added. There is no rollback way now. >