On Sep 4, 2013, at 4:33 AM, George Bosilca <bosi...@icl.utk.edu> wrote:
> You can confirm that the slowdown happen during the MPI initialization stages > by profiling the application (especially the MPI_Init call). You can also try just launching "MPI hello world" (i.e., examples/hello_c.c). It just calls MPI_INIT / MPI_FINALIZE. Additionally, you might want to try launching the ring program, too (examples/ring_c.c). That program sends a small message around in a ring, which forces some MPI communication to occur, and therefore does at least some level of setup in the BTLs, etc. (remember: most BTLs are lazy-connect, so they don't actually do anything until the first send. So a simple "ring" program sets up *some* BTL connections, but not nearly all of them). -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
