Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753283AbdCPRmA (ORCPT ); Thu, 16 Mar 2017 13:42:00 -0400 Received: from mx2.suse.de ([195.135.220.15]:48288 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752179AbdCPRly (ORCPT ); Thu, 16 Mar 2017 13:41:54 -0400 Date: Thu, 16 Mar 2017 18:40:51 +0100 From: Michal Hocko To: "Kani, Toshimitsu" Cc: "zhenzhang.zhang@huawei.com" , "tangchen@cn.fujitsu.com" , "arbab@linux.vnet.ibm.com" , "vkuznets@redhat.com" , "linux-mm@kvack.org" , "daniel.kiper@oracle.com" , "xieyisheng1@huawei.com" , "linux-kernel@vger.kernel.org" , "iamjoonsoo.kim@lge.com" , "qiuxishi@huawei.com" , "yasu.isimatu@gmail.com" , "akpm@linux-foundation.org" , "aarcange@redhat.com" , "vbabka@suse.cz" , "imammedo@redhat.com" , "rientjes@google.com" , "mgorman@suse.de" , "ak@linux.intel.com" , "slaoub@gmail.com" Subject: Re: [RFC PATCH] rework memory hotplug onlining Message-ID: <20170316174050.GA13654@dhcp22.suse.cz> References: <20170315091347.GA32626@dhcp22.suse.cz> <1489622542.9118.8.camel@hpe.com> <20170316085404.GE30501@dhcp22.suse.cz> <1489688018.9118.14.camel@hpe.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1489688018.9118.14.camel@hpe.com> 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 Content-Length: 1180 Lines: 29 On Thu 16-03-17 17:19:34, Kani, Toshimitsu wrote: > On Thu, 2017-03-16 at 09:54 +0100, Michal Hocko wrote: > > On Wed 15-03-17 23:08:14, Kani, Toshimitsu wrote: > > > On Wed, 2017-03-15 at 10:13 +0100, Michal Hocko wrote: > : > > > > - zone = page_zone(pfn_to_page(valid_start)); > > > > > > Please do not remove the fix made in a96dfddbcc043. zone needs to > > > be set from valid_start, not from start_pfn. > > > > Thanks for pointing this out. I was scratching my head about this > > part but was too tired from previous git archeology so I didn't check > > the history of this particular part. > > > > I will restore the original behavior but before I do that I am really > > curious whether partial memblocks are even supported for onlining. > > Maybe I am missing something but I do not see any explicit checks for > > NULL struct page when we set zone boundaries or online a memblock. Is > > it possible those memblocks are just never hotplugable? > > check_hotplug_memory_range() checks if a given range is aligned by the > section size. Ohh, right you are! I have completely missed check_hotplug_memory_range. Thanks for pointing it out. -- Michal Hocko SUSE Labs