From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 03 Oct 2005 07:45:59 -0700 From: "Martin J. Bligh" Reply-To: "Martin J. Bligh" Subject: Re: [PATCH 00/07][RFC] i386: NUMA emulation Message-ID: <77150000.1128350759@[10.10.2.4]> In-Reply-To: References: dlang@dlang.diginsite.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: David Lang , Magnus Damm Cc: Dave Hansen , Magnus Damm , linux-mm , Linux Kernel Mailing List List-ID: --David Lang wrote (on Monday, October 03, 2005 00:34:40 -0700): > On Mon, 3 Oct 2005, Magnus Damm wrote: > >> On 10/1/05, Dave Hansen wrote: >>> 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. >> >> Yes, this patch set removes "NUMA depends on SMP". It also adds some >> simple NUMA emulation code too, but I am sure you are aware of that! >> =) >> >> I agree that it is very unlikely to find a single-processor NUMA >> system in the real world. So yes, "[PATCH 02/07] i386: numa on >> non-smp" adds _some_ extra complexity. But because SMP is set when >> supporting more than one cpu, and NUMA is set when supporting more >> than one memory node, I see no reason why they should be dependent on >> each other. Except that they depend on each other today and breaking >> them loose will increase complexity a bit. > > hmm, observation from the peanut gallery, would it make sene to look at > useing the NUMA code on single proc machines that use PAE to access > more then 4G or ram on a 32 bit system? 2 problems: 1) there aren't any ;-) 2) The memory is not physically differently separated from the CPUs, so it's not NUMA. M. -- 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