Re: [libvirt] Problem with setting up KVM guests to use HugePages

Michal Privoznik <mprivozn <at> redhat.com> writes: > > On 10.06.2015 01:05, Vivi L wrote: > > Kashyap Chamarthy <kchamart <at> redhat.com> writes: > > > > > >> You might want re-test by explicitly setting the 'page' element and > >> 'size' attribute? From my test, I had something like this: > >> > >> $ virsh dumpxml f21-vm | grep hugepages -B3 -A2 > >> <memory unit='KiB'>2000896</memory> > >> <currentMemory unit='KiB'>2000000</currentMemory> > >> <memoryBacking> > >> <hugepages> > >> <page size='2048' unit='KiB' nodeset='0'/> > >> </hugepages> > >> </memoryBacking> > >> <vcpu placement='static'>8</vcpu> > >> > >> I haven't tested this exhaustively, but some basic test notes here: > >> > >> https://kashyapc.fedorapeople.org/virt/test-hugepages-with-libvirt.txt > > > > Current QEMU does not support setting <page> element. Could it be the > > cause of my aforementioned problem? > > > > unsupported configuration: huge pages per NUMA node are not supported > > with this QEMU > > > > So this is explanation why the memory for you guest is not backed by > hugepages. I thought setting hugepages per NUMA node is a nice-to-have feature. Is it required to enable the use of hugepages for the guest?