Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934604Ab0KQIQy (ORCPT ); Wed, 17 Nov 2010 03:16:54 -0500 Received: from smtp-out.google.com ([74.125.121.35]:12152 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934594Ab0KQIQx (ORCPT ); Wed, 17 Nov 2010 03:16:53 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version:content-type; b=cjXjXQgR60EIPmfCmWpKL58QrEeWVk9BbWi8JgG3VsAeAXV91GM7MMqAxPyhpxje36 9nqS5mz3ap/vNRr9QDZA== Date: Wed, 17 Nov 2010 00:16:47 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Shaohui Zheng cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, haicheng.li@linux.intel.com, lethal@linux-sh.org, ak@linux.intel.com, shaohui.zheng@linux.intel.com, Yinghai Lu , Haicheng Li Subject: Re: [2/8,v3] NUMA Hotplug Emulator: infrastructure of NUMA hotplug emulation In-Reply-To: <20101117021000.568681101@intel.com> Message-ID: References: <20101117020759.016741414@intel.com> <20101117021000.568681101@intel.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1365 Lines: 32 On Wed, 17 Nov 2010, shaohui.zheng@intel.com wrote: > From: Haicheng Li > > NUMA hotplug emulator introduces a new node state N_HIDDEN to > identify the fake offlined node. It firstly hides RAM via E820 > table and then emulates fake offlined nodes with the hidden RAM. > Hmm, why can't you use numa=hide to hide a specified quantity of memory from the kernel and then use the add_memory() interface to hot-add the offlined memory in the desired quantity? In other words, why do you need to track the offlined nodes with a state? The userspace interface would take a desired size of hidden memory to hot-add and the node id would be the first_unset_node(node_online_map). > After system bootup, user is able to hotplug-add these offlined > nodes, which is just similar to a real hardware hotplug behavior. > > Using boot option "numa=hide=N*size" to fake offlined nodes: > - N is the number of hidden nodes > - size is the memory size (in MB) per hidden node. > size should be parsed with memparse() so users can specify 'M' or 'G', it would even make your parsing code simpler. -- 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/