Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933353Ab2K0KA3 (ORCPT ); Tue, 27 Nov 2012 05:00:29 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:49539 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933260Ab2K0KAZ (ORCPT ); Tue, 27 Nov 2012 05:00:25 -0500 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <50B48F0B.60704@jp.fujitsu.com> Date: Tue, 27 Nov 2012 18:59:39 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:16.0) Gecko/20121026 Thunderbird/16.0.2 MIME-Version: 1.0 To: "H. Peter Anvin" , Tang Chen CC: Bob Liu , , , , , , , , , , , , , , , 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1978 Lines: 62 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 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/