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From: Graham E Fagg (fagg_at_[hidden])
Date: 2006-06-29 18:01:50

On Thu, 29 Jun 2006, Doug Gregor wrote:
> Are there other settings I can tweak to try to find the algorithm
> that it's deciding to use at run-time?

Yes just: -mca coll_base_verbose 1
will show whats being decided at run time. i.e.

[reliant:25351] ompi_coll_tuned_bcast_intra_dec_fixed
[reliant:25351] ompi_coll_tuned_bcast_intra_bintree rank 0 root 0 ss 0

shows that a bcast was called (dec_fixed means runtime decision is default
compiled in) and it decided to use a binary tree, the caller was ranb 0,
root was rank 0 and segment size was 0 (i.e. no segmenting used)

if you get different answers on any of the nodes (other than their rank)
then we (I) have a problem!

Dr Graham E. Fagg | Distributed, Parallel and Meta-Computing
Innovative Computing Lab. PVM3.4, HARNESS, FT-MPI, SNIPE & Open MPI
Computer Science Dept | Suite 203, 1122 Volunteer Blvd,
University of Tennessee | Knoxville, Tennessee, USA. TN 37996-3450
Email: fagg_at_[hidden] | Phone:+1(865)974-5790 | Fax:+1(865)974-8296
Broken complex systems are always derived from working simple systems