Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754278Ab0KUPRV (ORCPT ); Sun, 21 Nov 2010 10:17:21 -0500 Received: from mga11.intel.com ([192.55.52.93]:26820 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752291Ab0KUPRU convert rfc822-to-8bit (ORCPT ); Sun, 21 Nov 2010 10:17:20 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.59,231,1288594800"; d="scan'208";a="859916510" From: "Li, Haicheng" 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" Date: Sun, 21 Nov 2010 23:16:57 +0800 Subject: RE: [8/8,v3] NUMA Hotplug Emulator: documentation Thread-Topic: [8/8,v3] NUMA Hotplug Emulator: documentation Thread-Index: AcuJjOcK0Rkk8us5RiaOVLx2wnO10QAAfW4g 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> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1540 Lines: 36 Am?rico Wang wrote: > On Wed, Nov 17, 2010 at 10:08:07AM +0800, shaohui.zheng@intel.com > wrote: >> +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=N" hide CPUs >> + N is the number of initialize CPUs >> + - Using boot option "cpu_hpe=on" 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 >> + > > 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 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/