George,
Can you try out the changes I just commited on the trunk? We were doing
more select/recvs then necessary.
Thanks,
Tim
George Bosilca wrote:
I run Netpipe on 4 different clusters with differents OSes and Eternet
devices. The results is that nearly the same behaviour happens all the
time for small messages. Basically, our latency is really bad. Attached
are 2 of the graphs on one MAC OS X cluster (wotan) and a Linux 2.6.10
32 bits one. The graph are for Netpipe compiled over tcp, and for Open
MPI with all the PMLs (uniq, teg and ob1).Here is the global trend:
- we are always slower than native TCP (what a guess!)
- uniq is faster than teg by a fraction of second (it's more visible on
fast networks).
- teg and uniq are always better than ob1 in terms of latency.
- the behaviour of ob1 differ on wotan and boba. On boba the
performances are a lot closer to the other PML when on wotan it's like
40 micro-second slower (it nearly double the raw TCP latency).
On the same nodes I run other Netpipe with SM and MX and the results are
pretty good. So I think we have this latency problem only on TCP. I will
take a look to see how exactly is happens but any help is welcome.
george.
"We must accept finite disappointment, but we must never lose infinite
hope."
Martin Luther King
------------------------------------------------------------------------
_______________________________________________
devel mailing list
de...@open-mpi.org
http://www.open-mpi.org/mailman/listinfo.cgi/devel
