From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e36.co.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 58273DDE0C for ; Sat, 8 Dec 2007 09:22:59 +1100 (EST) Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e36.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id lB7MMuRv024748 for ; Fri, 7 Dec 2007 17:22:56 -0500 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id lB7MMufE169222 for ; Fri, 7 Dec 2007 15:22:56 -0700 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id lB7MMtQT004124 for ; Fri, 7 Dec 2007 15:22:56 -0700 Message-ID: <4759C7BD.5060803@linux.vnet.ibm.com> Date: Sat, 08 Dec 2007 03:52:53 +0530 From: Balbir Singh MIME-Version: 1.0 To: Arnd Bergmann Subject: Re: [PATCH] Fake NUMA emulation for PowerPC References: <20071207211425.10223.91240.sendpatchset@balbir-laptop> <200712072301.38723.arnd@arndb.de> In-Reply-To: <200712072301.38723.arnd@arndb.de> Content-Type: text/plain; charset=ISO-8859-1 Cc: linuxppc-dev@ozlabs.org, LKML Reply-To: balbir@linux.vnet.ibm.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Arnd Bergmann wrote: > On Friday 07 December 2007, Balbir Singh wrote: >> Here's a dumb simple implementation of fake NUMA nodes for PowerPC. Fake >> NUMA nodes can be specified using the following command line option >> >> numa=fake= >> >> node range is of the format ,,... > > Excellent idea! I'd love to have this in RHEL5u1, because that would make > that distro boot on certain machines that have more memory than is supported > without an iommu driver. The problem we have is that when you simply > say mem=1G but all of the first gigabyte is on the first node, you end > up with a memoryless node, which is not supported. > > Unfortunately, it comes too late for me now, as all new distros already boot > on Cell machines that need an IOMMU. Very interesting use case! I am sure there are others were fake NUMA nodes can be applied. I just listed one other in another email, apart from using it for playing around with NUMA like machines. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL