Re: NUMA TODO-list for xen-devel

[Andre Przywara <andre.przywara@amd.com>]

On 08/03/2012 12:40 PM, Jan Beulich wrote:
>>>> On 03.08.12 at 12:02, Andre Przywara <andre.przywara@amd.com> wrote:
>> On 08/01/2012 06:16 PM, Dario Faggioli wrote:
>>> Hi everyone,
>>>
>>> With automatic placement finally landing into xen-unstable, I stated
>>> thinking about what I could work on next, still in the field of
>>> improving Xen's NUMA support. Well, it turned out that running out of
>>> things to do is not an option! :-O
>>>
>>> In fact, I can think of quite a bit of open issues in that area, that I'm
>>> just braindumping here.
>>
>>> ...
>>>
>>>          * automatic placement of Dom0, if possible (my current series is
>>>            only affecting DomU)
>>
>> I think Dom0 NUMA awareness should be one of the top priorities. If I
>> boot my 8-node box with Xen, I end up with a NUMA-clueless Dom0 which
>> actually has memory from all 8 nodes and thinks it's memory is flat.
>> There are some tricks to confine it to node 0 (dom0_mem=<memory of
>> node0> dom0_vcpus=<cores in node0> dom0_vcpus_pin), but this requires
>> intimate knowledge of the systems parameters and is error-prone.
>
> How about "dom0_mem=node<n> dom0_vcpus=node<n>" as
> an extension to the current options?

Yes, that sounds like a good idea. And relatively easy to implement.
Maybe a list or a number of nodes (to make it more complicated ;-)

Regards,
Andre.

-- 
Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany