From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e5.ny.us.ibm.com (8.12.11/8.12.11) with ESMTP id j8UFNlnA008076 for ; Fri, 30 Sep 2005 11:23:47 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay04.pok.ibm.com (8.12.10/NCO/VERS6.7) with ESMTP id j8UFNlon090254 for ; Fri, 30 Sep 2005 11:23:47 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11/8.13.3) with ESMTP id j8UFNlvJ026724 for ; Fri, 30 Sep 2005 11:23:47 -0400 Subject: Re: [PATCH 00/07][RFC] i386: NUMA emulation From: Dave Hansen In-Reply-To: <20050930073232.10631.63786.sendpatchset@cherry.local> References: <20050930073232.10631.63786.sendpatchset@cherry.local> Content-Type: text/plain Date: Fri, 30 Sep 2005 08:23:44 -0700 Message-Id: <1128093825.6145.26.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Magnus Damm Cc: linux-mm , Linux Kernel Mailing List List-ID: On Fri, 2005-09-30 at 16:33 +0900, Magnus Damm wrote: > These patches implement NUMA memory node emulation for regular i386 PC:s. > > NUMA emulation could be used to provide coarse-grained memory resource control > using CPUSETS. Another use is as a test environment for NUMA memory code or > CPUSETS using an i386 emulator such as QEMU. This patch set basically allows the "NUMA depends on SMP" dependency to be removed. I'm not sure this is the right approach. There will likely never be a real-world NUMA system without SMP. So, this set would seem to include some increased (#ifdef) complexity for supporting SMP && ! NUMA, which will likely never happen in the real world. Also, I worry that simply #ifdef'ing things out like CPUsets' update means that CPUsets lacks some kind of abstraction that it should have been using in the first place. An #ifdef just papers over the real problem. I think it would likely be cleaner if the approach was to emulate an SMP NUMA system where each NUMA node simply doesn't have all of its CPUs online. -- Dave -- 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/ . Don't email: email@kvack.org