Ashley Pittman wrote: > Patrick Geoffray wrote: > >> I would bet that UPC could more efficiently leverage a strided or vector >> communication primitive instead of message aggregation. I don't know if >> GasNet provides one, I know ARMCI does. >> > > GasNet does however get extra credit for having a asynchronous > collective, namely barrier. Unfortunately when you read the spec it's > actually a special case asynchronous reduce which is almost impossible > to optimise anything like as well as barrier which is a shame. > All,
Berkeley's recent paper on the some optimization techniques that they have applied within their UPC compiler emphasizes reducing and hoisting shared pointer references, maximally split-phased reads and writes (implying that GASnet can do what Ashley suggests), and aggregating- coalescing communication. I have only read half of it, but no mention of pipelining or pseudo-vector operations (too bad) ... this would seem to be harder to do as it would required whole loop analysis. You may be interested in Googling for it: "Communication Optimizations for Fine-Grained UPC Applications" Wei-Yu Chen Costin Iancu Kathy Yelick Regards, rbw -- Richard B. Walsh Project Manager Network Computing Services, Inc. Army High Performance Computing Research Center (AHPCRC) [EMAIL PROTECTED] | 612.337.3467 > > "Making predictions is hard, especially about the future." > > Nils Bohr ----------------------------------------------------------------------- This message (including any attachments) may contain proprietary or privileged information, the use and disclosure of which is legally restricted. If you have received this message in error please notify the sender by reply message, do not otherwise distribute it, and delete this message, with all of its contents, from your files. ----------------------------------------------------------------------- _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
