[OMPI users] short message maximum and btl_tcp_eager_limit

[chris . neale]

Hello, I am using Open-mpi with Gromacs. We have an 88 node single processor
pentium 4 cluster conected by ethernet and running linux. I want to acheive a
short message tcp maximum length of 512kb. In lam, this would have been a
configure option --with-tcp-short=524288. I am intending to use open-mpi with a
runtime option --mca btl_tcp_eager_limit 524288. Is that the only thing that I
need to do in order to acheive a short message max. length of 512kb? 

What about:

btl_tcp_min_send_size
btl_tcp_max_send_size

And how is this affected by:

btl_tcp_min_rdma_size
btl_tcp_max_rdma_size

And should I set btl_openib_use_eager_rdma = 0 if I am not using InfiniBand?

Many thanks.

Chris Neale.

[OMPI users] tcp short settings

[chris . neale]

I previously posted this basic question about how to get a max short message
size of 512kb instead of 64kb:
http://www.open-mpi.org/community/lists/users/2006/08/1803.php
Appologies for the repost, but I simply can't figure this out.
My application (Gromacs) works fine with LAM.

I have tried:
mpirun --mca btl_tcp_eager_limit 524288 --mca btl_tcp_max_send_size 524288 --mca
btl_tcp_min_rdma_size 524288 --mca btl_tcp_sndbuf 1048576 --mca btl_tcp_rcvbuf
1048576
*Crashes immediately with a MPI_Alltoall error

--mca btl_tcp_eager_limit 524288 --mca btl_tcp_min_send_size 524288 --mca
btl_tcp_max_send_size 1048576 --mca btl_tcp_min_rdma_size 1048576 --mca
btl_tcp_sndbuf 1048576 --mca btl_tcp_rcvbuf 1048576 --mca btl_base_verbose 1
--mca btl_base_debug
*Same thing

mpirun --mca btl_tcp_eager_limit 524288 
*Same thing

mpirun --mca btl_tcp_eager_limit 131072
*Seems to work, but no benifit (I need at least 223560)

mpirun --mca btl_tcp_eager_limit 141072
*Tried this only as a test, Overloaded the main node.

Much appreciation and thanks,
Chris Neale.