From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx153.postini.com [74.125.245.153]) by kanga.kvack.org (Postfix) with SMTP id 65B5F6B009B for ; Tue, 27 Nov 2012 05:00:23 -0500 (EST) Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 8BB9F3EE0C0 for ; Tue, 27 Nov 2012 19:00:21 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 7176745DEC3 for ; Tue, 27 Nov 2012 19:00:21 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 5518D45DEBA for ; Tue, 27 Nov 2012 19:00:21 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 4777A1DB8045 for ; Tue, 27 Nov 2012 19:00:21 +0900 (JST) Received: from g01jpexchkw30.g01.fujitsu.local (g01jpexchkw30.g01.fujitsu.local [10.0.193.113]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id EBDC51DB8047 for ; Tue, 27 Nov 2012 19:00:20 +0900 (JST) Message-ID: <50B48F0B.60704@jp.fujitsu.com> Date: Tue, 27 Nov 2012 18:59:39 +0900 From: Yasuaki Ishimatsu MIME-Version: 1.0 Subject: Re: [PATCH v2 0/5] Add movablecore_map boot option References: <1353667445-7593-1-git-send-email-tangchen@cn.fujitsu.com> <50B479FA.6010307@cn.fujitsu.com> <50B47EB7.20000@zytor.com> In-Reply-To: <50B47EB7.20000@zytor.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "H. Peter Anvin" , Tang Chen Cc: Bob Liu , akpm@linux-foundation.org, rob@landley.net, laijs@cn.fujitsu.com, wency@cn.fujitsu.com, linfeng@cn.fujitsu.com, jiang.liu@huawei.com, yinghai@kernel.org, kosaki.motohiro@jp.fujitsu.com, minchan.kim@gmail.com, mgorman@suse.de, rientjes@google.com, rusty@rustcorp.com.au, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org Hi HPA and Tang, 2012/11/27 17:49, H. Peter Anvin wrote: > On 11/27/2012 12:29 AM, Tang Chen wrote: >> Another approach is like the following: >> movable_node = 1,3-5,8 >> This could set all the memory on the nodes to be movable. And the rest >> of memory works as usual. But movablecore_map is more flexible. > > ... but *much* harder for users, so movable_node is better in most cases. It seems that movable_node is easier to use than movablecore_map. But I do not think movable_node is better because the node number is set by OS and changed easily. For exmaple: If system has 4 nodes and we set moveble_node=2, we can hot remove node2. node0 node1 node2 node3 +-----+ +-----+ +-----+ +-----+ | | | | |/////| | | | | | | |/////| | | | | | | |/////| | | | | | | |/////| | | +-----+ +-----+ +-----+ +-----+ movable node But if we hot remove node2 and reboot the system, node3 is changed to node2 and set to movable node. node0 node1 node2 +-----+ +-----+ +-----+ | | | | |/////| | | | | |/////| | | | | |/////| | | | | |/////| +-----+ +-----+ +-----+ movable node Originally, node3 is not movable node. Changing the node attribution to movable node is not intended. So if user uses movable_node, user must confirm whether boot option is correctly set at hotplug. But memory range is set by firmware and not changed. So if we set node2 as movable node by movablecore_map, the issue does not occur. Thanks, Yasuaki Ishimatsu > > -hpa > -- 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