Andreas -- I added the sqrt() change, which is the most important change, and then did a 2nd commit with the whitespace cleanup. The sqrt change will likely be in 1.7.5. I credited you in the commit log; you'll likely also get credited in NEWS.
Thank you for the patch! On Dec 19, 2013, at 9:37 AM, Andreas Schäfer <gent...@gmx.de> wrote: > Dear all, > > please find attached a (trivial) patch to MPI_Dims_create(). When > computing the prime factors of nnodes, it is sufficient to check for > primes less or equal to sqrt(nnodes). > > This was not so much of a problem in the past, but now that Tier 0 > systems are capable of running O(10^6) MPI processes, the difference > in execution time is on the order of seconds (e.g. 8.86s vs. 0.04s on > my notebook, with nnproc = 10^6). > > Best > -Andreas > > PS: oh, and the patch removes some trailing whitespace. Yuck. :-) > > > -- > ========================================================== > Andreas Schäfer > HPC and Grid Computing > Chair of Computer Science 3 > Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany > +49 9131 85-27910 > PGP/GPG key via keyserver > http://www.libgeodecomp.org > ========================================================== > > (\___/) > (+'.'+) > (")_(") > This is Bunny. Copy and paste Bunny into your > signature to help him gain world domination! > <mpi_dims_create_speedup.patch>_______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
