Jeff Lane
2008-Apr-29 19:43 UTC
[Xen-users] How can you tell if NUMA is turned on in the Hypervisor?
I allegedly have some NUMA support in my hypervisor (this is Xen 3.2) I booted with numa=on but don''t see something obvious to clue me in that NUMA is in fact on and being used. On non-Xen systems, there''s usually a few messages about SRAT tables... on Xen however, looking at xm dmesg I can''t see anything that easy and obvious... So , how can I verify that NUMA is in fact on? Cheers Jeff -- ------------------> Jeffrey Lane - W4KDH <------------------- www.jefflane.org Another cog in the great Corporate Wheel The internet has no government, no constitution, no laws, no rights, no police, no courts. Don''t talk about fairness or innocence, and don''t talk about what should be done. Instead, talk about what is being done and what will be done by the amorphous unreachable undefinable blob called "the internet user base." -Paul Vixie _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Todd Deshane
2008-Apr-30 22:21 UTC
Re: [Xen-users] How can you tell if NUMA is turned on in the Hypervisor?
Hi Jeff, On Tue, Apr 29, 2008 at 3:43 PM, Jeff Lane <sundowner225@gmail.com> wrote:> I allegedly have some NUMA support in my hypervisor (this is Xen 3.2) > > I booted with numa=on but don''t see something obvious to clue me in > that NUMA is in fact on and being used. > > On non-Xen systems, there''s usually a few messages about SRAT > tables... on Xen however, looking at xm dmesg I can''t see anything > that easy and obvious... > > So , how can I verify that NUMA is in fact on? >Try xm info | grep nr_nodes nr_nodes > 1 implies NUMA nr_nodes == 1 imples not NUMA Cheers, Todd _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Jeff Lane
2008-May-01 13:59 UTC
Re: [Xen-users] How can you tell if NUMA is turned on in the Hypervisor?
On Wed, Apr 30, 2008 at 6:21 PM, Todd Deshane <deshantm@gmail.com> wrote:> Try xm info | grep nr_nodes > > nr_nodes > 1 implies NUMA > nr_nodes == 1 imples not NUMAThanks Todd! One other question though... does that apply equally to multi-noded systems like the IBM x3950? I have a few of those used for test... a couple are 2 node machines, while one is an 8 node. That''s the biggest reason for needing NUMA, as anything (Xen or not) running on multi-noded systems runs better with NUMA :-) Cheers Jeff _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Todd Deshane
2008-May-01 14:54 UTC
Re: [Xen-users] How can you tell if NUMA is turned on in the Hypervisor?
Hi Jeff, On Thu, May 1, 2008 at 9:59 AM, Jeff Lane <sundowner225@gmail.com> wrote:> On Wed, Apr 30, 2008 at 6:21 PM, Todd Deshane <deshantm@gmail.com> wrote: > > > Try xm info | grep nr_nodes > > > > nr_nodes > 1 implies NUMA > > nr_nodes == 1 imples not NUMA > > > Thanks Todd! > > One other question though... does that apply equally to multi-noded > systems like the IBM x3950?I can''t tell from a quick look at the specs whether it is NUMA or not. Can you (or someone) try running the xm info command it? Or does somebody know if these multi-node IBM systems are NUMA or not? I have a few of those used for test... a> couple are 2 node machines, while one is an 8 node. That''s the > biggest reason for needing NUMA, as anything (Xen or not) running on > multi-noded systems runs better with NUMA :-) >Have you done any benchmarking that shows this? Any papers or references that confirm it? Cheers, Todd _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Jeff Lane
2008-May-01 15:57 UTC
Re: [Xen-users] How can you tell if NUMA is turned on in the Hypervisor?
On Thu, May 1, 2008 at 10:54 AM, Todd Deshane <deshantm@gmail.com> wrote:> Can you (or someone) try running the xm info command it? > Or does somebody know if these multi-node IBM systems are NUMA or not?They are... x3950, x3850, x3950M2, x3800 are all NUMA enabled systems.> I have a few of those used for test... a > > couple are 2 node machines, while one is an 8 node. That''s the > > biggest reason for needing NUMA, as anything (Xen or not) running on > > multi-noded systems runs better with NUMA :-) > > > > Have you done any benchmarking that shows this? Any papers or > references that confirm it?No... not really. It''s more of an ... empirical observation than anything else. I''ve just noticed that when running guests on these systems, and you also have to keep in mind that I am doing this using beta level RHEL and SLES code with their respective patched Xen code... One thing I noticed just by observation using these OSs and Xen is that HVM guests tend to run a LOT slower or seem to have more issues that para-virt guests. I have also noticed that when using NUMA, the HVM guests seem remarkably more responsive, just from a user perspective. But it''s all just by observation... I''m not so much concerned with overall performance and benchmarking as I am with stability and finding out whether or not these things simply work. If that makes any sense. -- ------------------> Jeffrey Lane - W4KDH <------------------- www.jefflane.org Another cog in the great Corporate Wheel The internet has no government, no constitution, no laws, no rights, no police, no courts. Don''t talk about fairness or innocence, and don''t talk about what should be done. Instead, talk about what is being done and what will be done by the amorphous unreachable undefinable blob called "the internet user base." -Paul Vixie _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users