From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f41.google.com (mail-oi0-f41.google.com [209.85.218.41]) by kanga.kvack.org (Postfix) with ESMTP id C525A6B0032 for ; Sun, 19 Apr 2015 22:15:00 -0400 (EDT) Received: by oica37 with SMTP id a37so111199550oic.0 for ; Sun, 19 Apr 2015 19:15:00 -0700 (PDT) Received: from szxga03-in.huawei.com (szxga03-in.huawei.com. [119.145.14.66]) by mx.google.com with ESMTP id gq13si11119495obb.82.2015.04.19.19.14.45 for ; Sun, 19 Apr 2015 19:15:00 -0700 (PDT) Message-ID: <55345756.40902@huawei.com> Date: Mon, 20 Apr 2015 09:33:10 +0800 From: Xishi Qiu MIME-Version: 1.0 Subject: Re: [PATCH 1/2 V2] memory-hotplug: fix BUG_ON in move_freepages() References: <5530E578.9070505@huawei.com> <5531679d.4642ec0a.1beb.3569@mx.google.com> In-Reply-To: <5531679d.4642ec0a.1beb.3569@mx.google.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Yasuaki Ishimatsu Cc: Andrew Morton , Yasuaki Ishimatsu , Kamezawa Hiroyuki , izumi.taku@jp.fujitsu.com, Tang Chen , Gu Zheng , Xiexiuqi , Mel Gorman , David Rientjes , Linux MM , LKML , yasu.ishimatsu@gmail.com On 2015/4/18 4:05, Yasuaki Ishimatsu wrote: > > Your patches will fix your issue. > But, if BIOS reports memory first at node hot add, pgdat can > not be initialized. > > Memory hot add flows are as follows: > > add_memory > ... > -> hotadd_new_pgdat() > ... > -> node_set_online(nid) > > When calling hotadd_new_pgdat() for a hot added node, the node is > offline because node_set_online() is not called yet. So if applying > your patches, the pgdat is not initialized in this case. > > Thanks, > Yasuaki Ishimatsu > Hi Yasuaki, I'm not quite understand, when BIOS reports memory first, why pgdat can not be initialized? When hotadd a new node, hotadd_new_pgdat() will be called too, and when hotadd memory to a existent node, it's no need to call hotadd_new_pgdat(), right? Thanks, Xishi Qiu -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753091AbbDTB5z (ORCPT ); Sun, 19 Apr 2015 21:57:55 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:41304 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751942AbbDTB5x (ORCPT ); Sun, 19 Apr 2015 21:57:53 -0400 Message-ID: <55345756.40902@huawei.com> Date: Mon, 20 Apr 2015 09:33:10 +0800 From: Xishi Qiu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Yasuaki Ishimatsu CC: Andrew Morton , Yasuaki Ishimatsu , Kamezawa Hiroyuki , , Tang Chen , Gu Zheng , Xiexiuqi , Mel Gorman , David Rientjes , Linux MM , LKML , Subject: Re: [PATCH 1/2 V2] memory-hotplug: fix BUG_ON in move_freepages() References: <5530E578.9070505@huawei.com> <5531679d.4642ec0a.1beb.3569@mx.google.com> In-Reply-To: <5531679d.4642ec0a.1beb.3569@mx.google.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020201.55345764.003C,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 77543297141c0bf8bd5cacd7bbb27712 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/4/18 4:05, Yasuaki Ishimatsu wrote: > > Your patches will fix your issue. > But, if BIOS reports memory first at node hot add, pgdat can > not be initialized. > > Memory hot add flows are as follows: > > add_memory > ... > -> hotadd_new_pgdat() > ... > -> node_set_online(nid) > > When calling hotadd_new_pgdat() for a hot added node, the node is > offline because node_set_online() is not called yet. So if applying > your patches, the pgdat is not initialized in this case. > > Thanks, > Yasuaki Ishimatsu > Hi Yasuaki, I'm not quite understand, when BIOS reports memory first, why pgdat can not be initialized? When hotadd a new node, hotadd_new_pgdat() will be called too, and when hotadd memory to a existent node, it's no need to call hotadd_new_pgdat(), right? Thanks, Xishi Qiu