From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Andre Przywara" Subject: Re: How does the numa flag affect memory allocation? Date: Wed, 21 Nov 2007 11:15:21 +0100 Message-ID: <47440539.4080905@amd.com> References: <089B0D75973E1241B941D0A9854F23FC09C5A544@USEA-EXCH2.na.uis.unisys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <089B0D75973E1241B941D0A9854F23FC09C5A544@USEA-EXCH2.na.uis.unisys.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org > It is my understanding that, with numa=3Don, Xen will try to allocate=20 > memory for a para VM from the same node as the CPUs that the VM's procs= =20 > are pinned to. Thats true for HVM guests, too. > Thus, in a multi-node system, if we specify a pinning to > a specific node's CPUs in a VM's config file, Xen=20 > will allocate the VM's initial memory from that same node at startup.=20 Correct. > My question is: does this location preference happen for all subsequent= =20 > memory allocation? In other words, if I boot a VM configured with some=20 > initial memory and pinned to CPUs in node-X, change the pinning of the=20 > VM's procs to CPUs in node-Y, and then use "xm mem-set" to allocate mor= e=20 > memory, does this new memory come from node-Y? AFAIK ballooing and NUMA are in the moment mutually exclusive. Currently I am working on NUMA PV guest support (multiple nodes within a guest). I posted preliminary patches for HVM guests in August. If you want to help, you are invited ;-) Regards, Andre. --=20 Andre Przywara AMD-Operating System Research Center (OSRC), Dresden, Germany Tel: +49 351 277-84917 ----to satisfy European Law for business letters: AMD Saxony Limited Liability Company & Co. KG Sitz (Gesch=E4ftsanschrift): Wilschdorfer Landstr. 101, 01109 Dresden,=20 Deutschland Registergericht Dresden: HRA 4896 vertretungsberechtigter Komplement=E4r: AMD Saxony LLC (Sitz Wilmington,=20 Delaware, USA) Gesch=E4ftsf=FChrer der AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy