On Wed, Jul 06, 2011 at 06:38:23PM +0200, Hartmann, O. wrote: > On 07/06/11 18:28, Steve Kargl wrote: > >On Wed, Jul 06, 2011 at 05:29:24PM +0200, O. Hartmann wrote: > >>I use SCHED_ULE on all machines, since it is supposed to be performing > >>better on multicore boxes, but there are lots of suggestions switching > >>back to the old SCHED_4BSD scheduler. > >> > >If you are using MPI in numerical codes, then you want > >to use SCHED_4BSD. I've posted numerous times about ULE > >and its very poor performance when using MPI. > > > >http://lists.freebsd.org/pipermail/freebsd-hackers/2008-October/026375.html > > > > Worth a try, > but most of my code I use is OpenMP, not MPI.
It may impact OpenMP. I don't have any OpenMP to test. But, if OpenMP is spawning as many or more threads than the number of available processors/cores, then I think you will have problems. > The post is of 2008, that's three years ago and 9.0 is on the brink to > become released ... I periodically ran the same type test in the 2008 post over the last three years. Nothing has changed. I even set up an account on one node in my cluster for jeffr to use. He was too busy to investigate at that time. -- Steve _______________________________________________ firstname.lastname@example.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"