On Nov 2, 2010, at 10:11 AM, <ananda.mu...@wipro.com> <ananda.mu...@wipro.com> wrote:
> Yes, I am calling MPI_Init_thread() with MPI_THREAD_MULTIPLE. And I have > enabled thread and mpi_threads while configuring OpenMPI. BTW, I am using > OpenMPI 1.4.2. > > It will be helpful to know if this is a design constraint or some > implementation defect. When you use MPI_THREAD_MULTIPLE, we're activating locks that aren't necessary when you're MPI_THREAD_SINGLE. These locks therefore cost overhead time that you don't normally see (and potentially system time as opposed to user time). To date, we haven't spent a huge amount of time optimizing the THREAD_MULTIPLE code paths. There's a number of efforts going on that may help with this, but it will take some time. -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
