From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: Re: [PATCH 1 of 3 v5/leftover] libxl: enable automatic placement of guests on NUMA nodes [and 1 more messages] Date: Wed, 18 Jul 2012 15:54:43 +0200 Message-ID: <5006C023.3050207@ts.fujitsu.com> References: <0411b2cebd725b193465.1341932614@Solace> <20485.35590.105351.434937@mariner.uk.xensource.com> <5fa66c8b9093399e5bc3.1342458792@Solace> <20485.43293.833036.352186@mariner.uk.xensource.com> <1342570947.11794.92.camel@Abyss> <1342602839.26734.6.camel@zakaz.uk.xensource.com> <1342604616.19530.123.camel@Solace> <1342605184.26734.19.camel@zakaz.uk.xensource.com> <20486.38718.474388.724787@mariner.uk.xensource.com> <5006BCC1.7050001@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5006BCC1.7050001@amd.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andre Przywara Cc: Ian Campbell , Stefano Stabellini , George Dunlap , Ian Jackson , xen-devel , Dario Faggioli List-Id: xen-devel@lists.xenproject.org Am 18.07.2012 15:40, schrieb Andre Przywara: > On 07/18/2012 01:00 PM, Ian Jackson wrote: >> Ian Campbell writes ("Re: [PATCH 1 of 3 v5/leftover] libxl: enable >> automatic placement of guests on NUMA nodes [and 1 more messages]"): >>> On Wed, 2012-07-18 at 10:43 +0100, Dario Faggioli wrote: >>>> What could be done is restricting automatic placement to guests that >>>> fits on 4 or 8 nodes for 4.2. >>> >>> 8 would mean on a 32 node system considering 10,518,300 combinations? >>> >>> 4 would mean on a 32 node system considering 35,960 combinations? On a >>> 64 node system it would mean 635,376 combinations. >>> >>> If that's the case then lets go with 4 as the limit for 4.2.0. >> >> What is the maximum number of NUMA nodes we might expect to see on a >> single system in the next five years? I would argue that 32 is too >> optimistic. 128 or 256 seem like more reasonable upper bounds. > > Wow, what are you talking about? > To calm this down from the AMD side: > The current Opteron NUMA architecture is limited to exactly 8 nodes. > This has ever been the case since the release of Opteron and changing > this is not trivial and will not happen in any near future. In general I > don't think we will see much bigger NUMA systems, but more cluster like > architectures. > > Maybe Juergen can comment on the Fujitsu side. I'm not aware of anything with more than 8 nodes. OTOH I'm in the SW department. I'm not sure I would hear about a larger machine long before it is announced in public. :-) Juergen -- Juergen Gross Principal Developer Operating Systems PDG ES&S SWE OS6 Telephone: +49 (0) 89 3222 2967 Fujitsu Technology Solutions e-mail: juergen.gross@ts.fujitsu.com Domagkstr. 28 Internet: ts.fujitsu.com D-80807 Muenchen Company details: ts.fujitsu.com/imprint.html