There are two places where you'll find info on page sizes. The first
one is under <cpu/> element, where all supported pages sizes are
listed. Then the second one is under each <cell/> element which refers
to concrete NUMA node. At this place, the size of page's pool is
reported. So the capabilities XML looks something like this:
<capabilities>
<host>
<uuid>01281cda-f352-cb11-a9db-e905fe22010c</uuid>
<cpu>
<arch>x86_64</arch>
<model>Westmere</model>
<vendor>Intel</vendor>
<topology sockets='1' cores='1' threads='1'/>
...
<pages unit='KiB' size='4'/>
<pages unit='KiB' size='2048'/>
<pages unit='KiB' size='1048576'/>
</cpu>
...
<topology>
<cells num='4'>
<cell id='0'>
<memory unit='KiB'>4054408</memory>
<pages unit='KiB' size='4'>1013602</pages>
<pages unit='KiB' size='2048'>3</pages>
<pages unit='KiB' size='1048576'>1</pages>
<distances/>
<cpus num='1'>
<cpu id='0' socket_id='0' core_id='0' siblings='0'/>
</cpus>
</cell>
<cell id='1'>
<memory unit='KiB'>4071072</memory>
<pages unit='KiB' size='4'>1017768</pages>
<pages unit='KiB' size='2048'>3</pages>
<pages unit='KiB' size='1048576'>1</pages>
<distances/>
<cpus num='1'>
<cpu id='1' socket_id='0' core_id='0' siblings='1'/>
</cpus>
</cell>
...
</cells>
</topology>
...
</host>
<guest/>
</capabilities>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
If user or management application wants to create a guest,
it may be useful to know the cost of internode latencies
before the guest resources are pinned. For example:
<capabilities>
<host>
...
<topology>
<cells num='2'>
<cell id='0'>
<memory unit='KiB'>4004132</memory>
<distances>
<sibling id='0' value='10'/>
<sibling id='1' value='20'/>
</distances>
<cpus num='2'>
<cpu id='0' socket_id='0' core_id='0' siblings='0'/>
<cpu id='2' socket_id='0' core_id='2' siblings='2'/>
</cpus>
</cell>
<cell id='1'>
<memory unit='KiB'>4030064</memory>
<distances>
<sibling id='0' value='20'/>
<sibling id='1' value='10'/>
</distances>
<cpus num='2'>
<cpu id='1' socket_id='0' core_id='0' siblings='1'/>
<cpu id='3' socket_id='0' core_id='2' siblings='3'/>
</cpus>
</cell>
</cells>
</topology>
...
</host>
...
</capabilities>
We can see the distance from node1 to node0 is 20 and within nodes 10.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This test creates a Fake NUMA topology with non-sequential cell ids
to check if libvirt properly handles the same
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com>
Signed-off-by: Pradipta Kr. Banerjee <bpradip@in.ibm.com>
