Hi,

I think you've hit similar issue as reported here:

https://bugzilla.redhat.com/show_bug.cgi?id=1812316

You're right, the hugepages are considered as allocated memory and it is a bug. I am working on a fix right now.

Regards,

Lucia

On Wed, Apr 15, 2020 at 1:21 PM Alan G <alan+ovirt@griff.me.uk> wrote:

Hi,

I seem to have found an issue when trying to setup a high performance VM utilising hugepages and NUMA pinning.

The VM is configured for 32GB RAM and uses hugepages of size 1G.

The host has two NUMA nodes each having 64GB RAM (for 128GB total system RAM).

No other VMs are running or otherwise pinned to the host.

The VM is pinned to node 0. And the required hugepages are allocated with

echo 32 > /sys/devices/system/node/node0/hugepages/hugepages-1048576kB/nr_hugepages

I then attempt to start the VM and get a pop-up error saying "cannot accommodate memory of VM's pinned virtual NUMA nodes within host's physical NUMA nodes".

However, if I remove the hugepages from node 0

echo 0 > /sys/devices/system/node/node0/hugepages/hugepages-1048576kB/nr_hugepages

Start the VM and then immediately re-create the hugepqages then everything works as expected.

It seems to me that oVirt is considering the hugepages as allocated memory even if they are not in use.

Is this correct?

Thanks,

Alan

_______________________________________________
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-leave@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/
List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/32QKZ2EQ5OKTMPJD4M6W7QK2FKFDFK2E/