Hi Blair, that's it! Thanks! My QEMU command line now features: > -object memory-backend-ram,id=ram-node0,size=7516192768,host- nodes=1,policy=bind > -numa node,nodeid=0,cpus=0-11,memdev=ram-node0
But I think it is supposed to work with the arguments I originally specified, since [1] does not mention a dependency on the <numa/> tag and libvirt does not return an error when saving the configuration. Or am I missing something? I will test this again on libvirt 3.0 when this [2] bugfix landed in the Arch repos. If this behavior still exists in v3, I will contact the libvirt mailinglist/IRC. Cheers, Jan [1] https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/ html/Virtualization_Tuning_and_Optimization_Guide/sect- Virtualization_Tuning_Optimization_Guide-NUMA-NUMA_and_libvirt.html#sect- Virtualization_Tuning_Optimization_Guide-NUMA-NUMA_and_libvirt- Domain_Processes [2] https://bugzilla.redhat.com/show_bug.cgi?id=1413773 Am Montag, 30. Januar 2017, 11:30:01 CET schrieb Blair Bethwaite: > Hi Jan, > > Looking back at your original pastebin I see you are not explicitly > specifying guest numa details. Perhaps your numatune needs the memnode > element, not sure if that is significant here but you could try: > > <numatune> > <memory mode='strict' nodeset='1'/> > <memnode cellid='0' mode='strict' nodeset='1'/> > </numatune> > > and then: > > <cpu mode='host-model'> > <model fallback='allow'/> > <topology sockets='1' cores='6' threads='2'/> > <numa> > <cell id='0' cpus='0-11' memory='7340032' unit='KiB'/> > </numa> > </cpu> > > Cheers, > > On 30 January 2017 at 07:02, Jan Wiele <j...@wiele.org> wrote: > > Am 2017-01-29 16:33, schrieb Alex Williamson: > >> On Sat, 28 Jan 2017 12:58:41 +0100 > >> > >> Thomas Lindroth <thomas.lindr...@gmail.com> wrote: > >>> On 01/27/2017 04:52 PM, Alex Williamson wrote: > >>> > vcpupin actually looks a little off though, just like on the host, the > >>> > VM is going to enumerate cores then threads > >>> > >>> Are you sure about that? Perhaps there is some numa trick I don't > >>> understand but it looks like the guest is a regular 6 cores > >>> with HT (<topology sockets='1' cores='6' threads='2'/>) and > >>> for me setups like that results in a layouts like this in the > >>> guest (qemu-2.8.0): > >>> > >>> cat /proc/cpuinfo |grep "core id" > >>> core id : 0 > >>> core id : 0 > >>> core id : 1 > >>> core id : 1 > >>> core id : 2 > >>> core id : 2 > >>> > >>> The ordering in the guest is threads then cores but for the > >>> host it's the other way around > >>> > >>> cat /proc/cpuinfo |grep "core id" > >>> core id : 0 > >>> core id : 1 > >>> core id : 2 > >>> core id : 3 > >>> core id : 0 > >>> core id : 1 > >>> core id : 2 > >>> core id : 3 > >>> > >>> Cores then threads. So to get a 1:1 match I have to use > >>> pinning like this which is similar to that numa setup. > >>> > >>> <vcpupin vcpu='0' cpuset='1'/> > >>> <vcpupin vcpu='1' cpuset='5'/> > >>> <vcpupin vcpu='2' cpuset='2'/> > >>> <vcpupin vcpu='3' cpuset='6'/> > >>> <vcpupin vcpu='4' cpuset='3'/> > >>> <vcpupin vcpu='5' cpuset='7'/> > >>> <topology sockets='1' cores='3' threads='2'/> > >> > >> Oh wow, maybe I'm completely off. I hadn't noticed the core-id > >> ordering in the VM, but indeed on my system the guest shows: > >> > >> core id : 0 > >> core id : 0 > >> core id : 1 > >> core id : 1 > >> core id : 2 > >> core id : 2 > >> core id : 3 > >> core id : 3 > >> > >> Any physical system I've seen has the ordering you show above, > >> enumerating cores then threads. Sorry Jan, maybe the way you had it > >> originally was optimal. Thanks, > >> > >> Alex > > > > Ah, good to know! I will change my config back to the original one. > > I was curious how I could get this information on a Windows system. After > > some googling I found coreinfo [1], which reports this: > > > > Logical to Physical Processor Map: > > **---------- Physical Processor 0 (Hyperthreaded) > > --**-------- Physical Processor 1 (Hyperthreaded) > > ----**------ Physical Processor 2 (Hyperthreaded) > > ------**---- Physical Processor 3 (Hyperthreaded) > > --------**-- Physical Processor 4 (Hyperthreaded) > > ----------** Physical Processor 5 (Hyperthreaded) > > > > But I'm still having my memory allocation problem: Can someone confirm > > that > > the numatune option actually works? I'm interested in the > > Kernel/Qemu/Libvirt version. > > > > Jan > > > > [1] https://technet.microsoft.com/en-us/sysinternals/cc835722.aspx > > > > > > _______________________________________________ > > vfio-users mailing list > > vfio-users@redhat.com > > https://www.redhat.com/mailman/listinfo/vfio-users _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
