Re: [libvirt] [RFC] NUMA topology specification
On 08/19/2011 01:35 AM, Bharata B Rao wrote:
May be something like this: (OPTION 2)
<cpu>
...
<topology sockets='1' cores='2' threads='1' nodeid='0'
cpus='0-1' mem='size'>
<topology sockets='1' cores='2' threads='1' nodeid='1'
cpus='2-3' mem='size'>
...
</cpu
This should result in a 2 node system with each node having 1 socket
with 2 cores.
Comments, suggestions ?
Option 2 (above) seems like the most logical interface to me. I would
not support putting this under <numatune> because of the high risk of
users confusing guest NUMA topology definition with host NUMA tuning.
I like the idea of merging this into <topology> to prevent errors with
specifying incompatible cpu and numa topologies but I think you can go a
step further (assuming my following assertion is valid). Since cpus are
assigned to numa nodes at the core level, and you are providing a
'nodeid' attribute, you can infer the 'cpus' attribute using
'cores' and
'nodeid' alone.
For your example above:
<topology sockets='1' cores='2' threads='1' nodeid='0'
mem='size'>
<topology sockets='1' cores='2' threads='1' nodeid='1'
mem='size'>
You have 4 cores total, each node is assigned 2. Assign cores to nodes
starting with core 0 and node 0.
--
Adam Litke
IBM Linux Technology Center