On Nov 22, 2010, at 11:35 AM, Barrett, Brian W wrote: > Um, the counter starts initialized at one.
Does that mean that we should or should not leave that extra _decrement() in there? > Brian > > On Nov 22, 2010, at 9:32 AM, Jeff Squyres wrote: > >> A user noticed a specific change that we made between 1.4.2 and 1.4.3: >> >> https://svn.open-mpi.org/trac/ompi/changeset/23448 >> >> which is from CMR https://svn.open-mpi.org/trac/ompi/ticket/2489, and >> originally from trunk https://svn.open-mpi.org/trac/ompi/changeset/23434. I >> removed the opal_progress_event_users_decrement() from ompi_mpi_init() >> because the ORTE DPM does its own _increment() and _decrement(). >> >> However, it seems that there was an unintended consequence of this -- look >> at the annotated Ganglia graph that the user sent (see attached). In 1.4.2, >> all of the idle time was "user" CPU usage. In 1.4.3, it's split between >> user and system CPU usage. The application that he used to test is >> basically an init / finalize test (with some additional MPI middleware). >> See: >> >> http://www.open-mpi.org/community/lists/users/2010/11/14773.php >> >> Can anyone think of why this occurs, and/or if it's a Bad Thing? >> >> If removing this decrement enabled a bunch more system CPU time, that would >> seem to imply that we're calling libevent more frequently than we used to >> (vs. polling the opal event callbacks), and therefore that there might now >> be an unmatched increment somewhere. >> >> Right...? >> >> -- >> Jeff Squyres >> jsquy...@cisco.com >> For corporate legal information go to: >> http://www.cisco.com/web/about/doing_business/legal/cri/ >> <openmpi143.jpeg><ATT00002..txt> > > -- > Brian W. Barrett > Dept. 1423: Scalable System Software > Sandia National Laboratories > > > > _______________________________________________ > 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/
