Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753110AbbDTDAD (ORCPT ); Sun, 19 Apr 2015 23:00:03 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:19904 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752780AbbDTDAA (ORCPT ); Sun, 19 Apr 2015 23:00:00 -0400 Message-ID: <55346B99.2060602@huawei.com> Date: Mon, 20 Apr 2015 10:59:37 +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: Gu Zheng CC: Yasuaki Ishimatsu , Andrew Morton , Yasuaki Ishimatsu , Kamezawa Hiroyuki , , Tang Chen , 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> <55345756.40902@huawei.com> <5534603a.36208c0a.4784.6286@mx.google.com> <55345FC4.4070404@cn.fujitsu.com> In-Reply-To: <55345FC4.4070404@cn.fujitsu.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1392 Lines: 44 On 2015/4/20 10:09, Gu Zheng wrote: > Hi Ishimatsu, Xishi, > > On 04/20/2015 10:11 AM, Yasuaki Ishimatsu wrote: > >> >>> When hot adding memory and creating new node, the node is offline. >>> And after calling node_set_online(), the node becomes online. >>> >>> Oh, sorry. I misread your ptaches. >>> >> >> Please ignore it... > > Seems also a misread to me. > I clear it (my worry) here: > If we set the node size to 0 here, it may hidden more things than we experted. > All the init chunks around with the size (spanned/present/managed...) will > be non-sense, and the user/caller will not get a summary of the hot added node > because of the changes here. > I am not sure the worry is necessary, please correct me if I missing something. > > Regards, > Gu > Hi Gu, My patch is just set size to 0 when hotadd a node(old or new). I know your worry, but I think it is not necessary. When we calculate the size, it uses "arch_zone_lowest_possible_pfn[]" and "memblock", and they are both from boot time. If we hotadd a new node, the calculated size is 0 too. When add momery, __add_zone() will grow the size and start. Thanks, Xishi Qiu -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/