From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752038AbaHRNNI (ORCPT ); Mon, 18 Aug 2014 09:13:08 -0400 Received: from mail-yk0-f175.google.com ([209.85.160.175]:63837 "EHLO mail-yk0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750709AbaHRNNG (ORCPT ); Mon, 18 Aug 2014 09:13:06 -0400 Date: Mon, 18 Aug 2014 09:13:01 -0400 From: Tejun Heo To: Xishi Qiu Cc: tangchen , Andrew Morton , Zhang Yanfei , Wen Congyang , "H. Peter Anvin" , Linux MM , LKML Subject: Re: [PATCH] mem-hotplug: let memblock skip the hotpluggable memory regions in __next_mem_range() Message-ID: <20140818131301.GA16425@mtj.dyndns.org> References: <53E8C5AA.5040506@huawei.com> <20140816130456.GH9305@htj.dyndns.org> <53EF6C79.3000603@huawei.com> <20140817110821.GM9305@htj.dyndns.org> <53F15330.5070606@cn.fujitsu.com> <53F17068.5000005@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53F17068.5000005@huawei.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 Hello, Xishi, Tang. On Mon, Aug 18, 2014 at 11:18:00AM +0800, Xishi Qiu wrote: > If all the nodes are marked hotpluggable flag, alloc node data will fail. > Because __next_mem_range_rev() will skip the hotpluggable memory regions. > numa_register_memblks() > setup_node_data() > memblock_find_in_range_node() > __memblock_find_range_top_down() > for_each_mem_range_rev() > __next_mem_range_rev() I'm not sure clearing hotplug flag for all memory is the best approach here. The problem is that there are places where we want to be selectively ignoring the hotplug status and apparently we may want it back later. Why not add an agument to memblock allocation / iteration functions so that hotplug area can be skipped selectively? Thanks. -- tejun