Richard Walsh wrote: > 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.
I was thinking of gasnet_barrier_notify() and gasnet_barrier_wait()/gasnet_barrier_try() specifically which allow you to pipeline useful code with barriers. It's a surprisingly useful trick and one that I hope will become commonplace in future. Ashley, _______________________________________________ Beowulf mailing list, [email protected] To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
