[libvirt] [PATCH 2/5] docs: Define XML schema for numa tuning and add docs

Osier Yang jyang at redhat.com
Fri May 6 02:25:31 UTC 2011


于 2011年05月05日 23:29, Daniel P. Berrange 写道:
> On Thu, May 05, 2011 at 05:38:27PM +0800, Osier Yang wrote:
>> Currently we only want to use "membind" function of numactl, but
>> perhaps more other functions in future, so introduce element
>> "<numatune>", future NUMA tuning related XML stuffs should go
>> into it.
>> ---
>>   docs/formatdomain.html.in |   17 +++++++++++++++++
>>   docs/schemas/domain.rng   |   20 ++++++++++++++++++++
>>   2 files changed, 37 insertions(+), 0 deletions(-)
>>
>> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
>> index 5013c48..6da6465 100644
>> --- a/docs/formatdomain.html.in
>> +++ b/docs/formatdomain.html.in
>> @@ -288,6 +288,9 @@
>>       <min_guarantee>65536</min_guarantee>
>>     </memtune>
>>     <vcpu cpuset="1-4,^3,6" current="1">2</vcpu>
>> +<numatune>
>> +<membind nodeset="1,2,!3-6">
>> +</numatune>
>
> I don't think we should be creating a new<numatune>  element here since
> it is not actually covering all aspects of NUMA tuning. We already have
> CPU NUMA pinning in the separate<vcpu>  element. NUMA memory pinning
> should likely be either in the<memtune>  or<memoryBacking>  elements,
> probably the latter.

Agree that it doesn't cover all aspects of NUMA tuning, actually
we also have <vcpupin>, the reason I did't put it into <memtune>
is that I'm not sure if we will also support other tuning stuffs.

>
> Also, it is not very nice to use a different syntax for negation for the
> VCPU specification, vs memory node specification "^3" vs "!3"

NUMA tuning use different syntax, actually also has "+", which is not
used by VCPU specification, so IMHO once we have to accept "+", "!"
should be accepted too, or we can do a converstion, from "^" to "!"?

>
> Looking to the future, we may want to consider how we'd allow host NUMA
> mapping on a fine grained basis, per guest NUMA node. eg It is possible
> with QEMU to actually define a guest visible NUMA topology for the virtual
> CPUs and memory using
>
>      -numa node[,mem=size][,cpus=cpu[-cpu]][,nodeid=node]
>
> We don't support that yet, which is something we ought to do. At which
> point you probably also want to be ale to map guest NUMA nodes to host
> NUMA nodes.

As far as I understand this, doesn't we need a standalone
<numatune> for things like this?

Thanks
Osier




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