From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 982C46B0087 for ; Sun, 21 Nov 2010 10:17:21 -0500 (EST) From: "Li, Haicheng" Date: Sun, 21 Nov 2010 23:16:57 +0800 Subject: RE: [8/8,v3] NUMA Hotplug Emulator: documentation Message-ID: <789F9655DD1B8F43B48D77C5D30659732FE95E71@shsmsx501.ccr.corp.intel.com> References: <20101117020759.016741414@intel.com> <20101117021000.985643862@intel.com> <20101121150344.GK9099@hack> In-Reply-To: <20101121150344.GK9099@hack> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org To: =?iso-8859-1?Q?Am=E9rico_Wang?= , "Zheng, Shaohui" Cc: "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" List-ID: Am=E9rico Wang wrote: > On Wed, Nov 17, 2010 at 10:08:07AM +0800, shaohui.zheng@intel.com > wrote:=20 >> +2) CPU hotplug emulation: >> + >> +The emulator reserve CPUs throu grub parameter, the reserved CPUs >> can be +hot-add/hot-remove in software method, it emulates the >> process of physical +cpu hotplug. + >> +When hotplug a CPU with emulator, we are using a logical CPU to >> emulate the CPU +socket hotplug process. For the CPU supported SMT, >> some logical CPUs are in the +same socket, but it may located in >> different NUMA node after we have emulator. +We put the logical CPU >> into a fake CPU socket, and assign it an unique +phys_proc_id. For >> the fake socket, we put one logical CPU in only. + + - to hide CPUs >> + - Using boot option "maxcpus=3DN" hide CPUs >> + N is the number of initialize CPUs >> + - Using boot option "cpu_hpe=3Don" to enable cpu hotplug emulation >> + when cpu_hpe is enabled, the rest CPUs will not be >> initialized + + - to hot-add CPU to node >> + $ echo nid > cpu/probe >> + >> + - to hot-remove CPU >> + $ echo nid > cpu/release >> + >=20 > Again, we already have software CPU hotplug, > i.e. /sys/devices/system/cpu/cpuX/online. online here is just for logical CPU online. what we're achieving here is to= emulate physical CPU hotadd. -haicheng= -- 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