Hi Gus, I played with collectives a few months ago. Details are here http://www.cse.scitech.ac.uk/disco/publications/WorkingNotes.ConnectX.pdf That was in the context of 1.2.6
You can get available tuning options by doing ompi_info -all -mca coll_tuned_use_dynamic_rules 1 | grep alltoall and similarly for other collectives. Best, Igor 2009/7/23 Gus Correa <g...@ldeo.columbia.edu>: > Dear OpenMPI experts > > I would like to experiment with the OpenMPI tuned collectives, > hoping to improve the performance of some programs we run > in production mode. > > However, I could not find any documentation on how to select the > different collective algorithms and other parameters. > In particular, I would love to read an explanation clarifying > the syntax and meaning of the lines on "dyn_rules" > file that is passed to > "-mca coll_tuned_dynamic_rules_filename ./dyn_rules" > > Recently there was an interesting discussion on the list > about this topic. It showed that choosing the right collective > algorithm can make a big difference in overall performance: > > http://www.open-mpi.org/community/lists/users/2009/05/9355.php > http://www.open-mpi.org/community/lists/users/2009/05/9399.php > http://www.open-mpi.org/community/lists/users/2009/05/9401.php > http://www.open-mpi.org/community/lists/users/2009/05/9419.php > > However, the thread was concentrated on "MPI_Alltoall". > Nothing was said about other collective functions. > Not much was said about the > "tuned collective dynamic rules" file syntax, > the meaning of its parameters, etc. > > Is there any source of information about that which I missed? > Thank you for any pointers or clarifications. > > Gus Correa > --------------------------------------------------------------------- > Gustavo Correa > Lamont-Doherty Earth Observatory - Columbia University > Palisades, NY, 10964-8000 - USA > --------------------------------------------------------------------- > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
