Re: numa=on broken

[Ryan Harper <ryanh@us.ibm.com>]

* Keir Fraser <Keir.Fraser@cl.cam.ac.uk> [2007-03-30 14:10]:
> On 30/3/07 19:55, "Ryan Harper" <ryanh@us.ibm.com> wrote:
> 
> >> This is just a simple exercise in code shuffling. :-)
> > 
> > Giving that try right now, let you know in a fewl.
> > 
> > I would have rather had the folks who changed the code actually test
> > with numa=on.
> > 
> > What are you thoughts about turning numa on by default or at least
> > getting a numa=on run on a two-socket opteron in the xen-rt regressions.
> 
> Turning on by default is pointless because guests are not restricted to
> running on specific nodes by default. Since manual intervention is required
> to achieve that (right now at least) requiring numa=on is not much of a
> hardship.

I'm getting ready to re-submit patches to export the topology information
so the userspace tools can use that info to make intelligent selections.
This was available back in October, but was never picked up, or even
commented upon.

> 
> Integration with xenrt is perhaps possible but we are constrained by machine
> resources. Numa=on has been broken for over a month and noone else had yet
> complained so it doesn't seem to be a priority for many people.

I spent a bit of last week pointing out to folks that NUMA was available
as it was never announced in the 3.0.4 release [1]notes AFAICT.  It may be
that the community wasn't aware that it was there to even test.  It is
indeed important to IBM and I've spoken with folks at AMD who have
expressed support for ensuring solid NUMA support in Xen.

In any case, thanks for the quick work on fixing this issue.

1. http://xensource.com/download/index_3.0.4.html

-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
(512) 838-9253   T/L: 678-9253
ryanh@us.ibm.com