Re: [discuss] Re: [PATCH 1/3] Zone reclaim V3: main patch

[Andi Kleen]

On Thu, Dec 08, 2005 at 03:35:05PM -0800, Christoph Lameter wrote:
> On Fri, 9 Dec 2005, Andi Kleen wrote:
> 
> > > My experience is that at 20 systems do not need zone reclaim yet.
> > 
> > I really cannot confirm your experience here.
> 
> Maybe the meaning of these numbers varies? I know that 10 is a local 
> access but the assumption in include/linux/numa.h that 20 is a remote 
> access is probably already a guess.

The spec seems to suggest it's roughly the NUMA factor scaled (so for 1.4
you would get 14). But I haven't actually seen a Opteron with correct
SLIT yet so I don't know what they use ...

> I know that our Altix machines seem to use 10 for a local and 20 for 
> nonlocal but same box. The distances then increase from there.

Unless non local same box is 2 times as slow as the local I wouldn't
consider that correct.  (I would expect the Altix to do better than that) 
-Andi
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