On Mon, Apr 07, 2008 at 07:28:07AM -0600, Ralph H Castain wrote: > > Also can you explain how > > allgather is implemented in orte (sorry if you already explained this once > > and I missed it). > > The default method is for each proc to send its modex data to its local > daemon. The local daemon collects the messages until all of its local procs > have contributed, then sends the collected data to the rank=0 application > proc. One rank=0 has received a message from every daemon, it xcasts the > collected result to all procs in its job. > Only collected result is compressed or messages from each proc to local daemon and messages from local daemon to rank=0 are compressed too? And, may be a stupid question, but I have to ask :) When rank=0 xcast collected modex it compress it once or for each rank separately. Also I think if rank=0 will compress each modex message during receive it can save some work during xcast.
-- Gleb.