Re: [PATCH 1/5] cpuset memory spread basic implementation

[Andi Kleen]

On Tuesday 07 February 2006 18:42, Christoph Lameter wrote:

> > > and therefore there are only small latencies  
> > > involved. NUMA only gives small benefits.
> > 
> > That's also not true. Everytime I get memory placement for 
> > process memory wrong users complain _very_ loudly and there 
> > are clear benefits in benchmarks too.
> 
> What are the latencies in an 8 way opteron system? I.e. Local memory, next 
> processor, most distant processor?

The NUMA factor is surprisingly good because of the way the cache coherency
works even the local memory access gets slower with more
nodes @) iirc it's <3. Worst case latency tends to be <200ns.

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/