[Beowulf] Moores Law is dying

Nifty Tom Mitchell niftyompi at niftyegg.com
Thu Apr 23 20:32:55 PDT 2009


On Wed, Apr 15, 2009 at 01:00:14PM -0700, Greg Lindahl wrote:
> On Tue, Apr 14, 2009 at 03:44:17PM -0700, Christian Bell wrote:
> 
> > Sure, capacity and conflict misses will apply like 
> > they do in any cache but Jon's statement remains correct -- in SPMD 
> > applications, you really want all processes to benefit from cache hits in 
> > your "single program".
> 
> ... then why do vendors make such a fuss about duplicating program
> text pages in big NUMA machines?
> 
> As an example:
> 
> www.sc2001.org/papers/pap.pap241.pdf


Good link -- still the key is in the phrase "big NUMA machines"
of the previous post.

    i.e. NUMA "non uniform memory access".

Replication of interesting pages can flatten the access times
across the machine and partly remove the Non from NUMA ---> UMA.
 
> The issue is that fetching from distant memory is expensive, even if
> there's no writing going on. Locality, locality, locality.

Exactly.

> -- greg

Later,
mitch (who should have read this thread a couple days ago, all the canapes are cold)

-- 
	T o m  M i t c h e l l 
	Found me a new hat, now what?




More information about the Beowulf mailing list