From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 112D36B0088 for ; Mon, 22 Nov 2010 11:01:07 -0500 (EST) Received: by gyh3 with SMTP id 3so4617425gyh.14 for ; Mon, 22 Nov 2010 08:01:06 -0800 (PST) Date: Tue, 23 Nov 2010 00:04:12 +0800 From: =?utf-8?Q?Am=C3=A9rico?= Wang Subject: Re: [8/8,v3] NUMA Hotplug Emulator: documentation Message-ID: <20101122160412.GE4137@hack> References: <20101117020759.016741414@intel.com> <20101117021000.985643862@intel.com> <20101121150344.GK9099@hack> <20101121233351.GA7626@shaohui> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20101121233351.GA7626@shaohui> Sender: owner-linux-mm@kvack.org To: Shaohui Zheng Cc: =?utf-8?Q?Am=C3=A9rico?= Wang , akpm@linux-foundation.org, 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, Haicheng Li List-ID: On Mon, Nov 22, 2010 at 07:33:51AM +0800, Shaohui Zheng wrote: >On Sun, Nov 21, 2010 at 11:03:45PM +0800, AmA(C)rico Wang wrote: >> >> >From your documentation above, it looks like you are trying >> to move one CPU between nodes? >Yes, you are correct. With cpu probe/release interface, you can hot-remove a >CPU from a node, and hot-add it to another node. Can I also move the CPU to another node _after_ it is hot-added? Or I have to hot-remove it first and then hot-add it again? >> >> >+ cpu_hpe=on/off >> >+ Enable/disable cpu hotplug emulation with software method. when cpu_hpe=on, >> >+ sysfs provides probe/release interface to hot add/remove cpu dynamically. >> >+ this option is disabled in default. >> >+ >> >> Why not just a CONFIG? IOW, why do we need to make another boot >> parameter for this? >Only the developer or QA will use the emulator, we did not want to change the >default action for common user who does not care the hotplug emulator, so we >use a kernel parameter as a switch. The common user is not aware the existence >of the emulator. > I think it is also useful to other Linux users, e.g. after I boot with "maxcpus=1", I can still bring the rest 3 CPU's back without reboot. Thanks. -- Live like a child, think like the god. -- 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