On Mon, Mar 26, 2007 at 03:58:59PM -0500, Richard Walsh wrote: > but of course aggregation is a legitimate optimization technique > because not all message patterns are of the Gups variety just as not > all memory references are absent locality.
This is true, although I would call it more of an "ease of use" issue. Everyone in the MPI arena already knows they're supposed to send as big of a message as possible, so it's fairly rare to find high-performance MPI codes that see an improvement with message aggregation. In an ideal world the programmer wouldn't have to explicitly think about aggregation, it would just happen. But today's codes don't assume that. I only referred to GUPs as it's a widely available microbenchmark which is not gamed by this optimization. But message rate and streaming bandwidth are completely wrecked. -- greg _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
