From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id E8A596B004A for ; Thu, 18 Nov 2010 16:19:34 -0500 (EST) Received: from wpaz37.hot.corp.google.com (wpaz37.hot.corp.google.com [172.24.198.101]) by smtp-out.google.com with ESMTP id oAILJWfT009665 for ; Thu, 18 Nov 2010 13:19:32 -0800 Received: from yxm34 (yxm34.prod.google.com [10.190.4.34]) by wpaz37.hot.corp.google.com with ESMTP id oAILJVk4032183 for ; Thu, 18 Nov 2010 13:19:31 -0800 Received: by yxm34 with SMTP id 34so2571879yxm.2 for ; Thu, 18 Nov 2010 13:19:30 -0800 (PST) Date: Thu, 18 Nov 2010 13:19:27 -0800 (PST) From: David Rientjes Subject: Re: [2/8,v3] NUMA Hotplug Emulator: infrastructure of NUMA hotplug emulation In-Reply-To: <20101118041407.GA2408@shaohui> Message-ID: References: <20101117020759.016741414@intel.com> <20101117021000.568681101@intel.com> <20101117075128.GA30254@shaohui> <20101118041407.GA2408@shaohui> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org 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 List-ID: On Thu, 18 Nov 2010, Shaohui Zheng wrote: > On Wed, Nov 17, 2010 at 01:10:50PM -0800, David Rientjes wrote: > > I don't understand why that's a requirement, NUMA emulation is a seperate > > feature. Although both are primarily used to test and instrument other VM > > and kernel code, NUMA emulation is restricted to only being used at boot > > to fake nodes on smaller machines and can be used to test things like the > > slab allocator. The NUMA hotplug emulator that you're developing here is > > primarily used to test the hotplug callbacks; for that use-case, it seems > > particularly helpful if nodes can be hotplugged of various sizes and node > > ids rather than having static characteristics that cannot be changed with > > a reboot. > > > I agree with you. the early emulator do the same thing as you said, but there > is already NUMA emulation to create fake node, our emulator also creates > fake nodes. We worried about that we will suffer the critiques from the community, > so we drop the original degsin. > > I did not know whether other engineers have the same attitude with you. I think > that I can publish both codes, and let the community to decide which one is prefered. > > In my personal opinion, both methods are acceptable for me. > The way that I've proposed it in my email to Dave was different: we use the memory hotplug interface to add and online the memory only after an interface has been added that will change the node mappings to first_unset_node(node_online_map). The memory hotplug interface may create a new pgdat, so this is the node creation mechanism that should be used as opposed to those in NUMA emulation. -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org