On Mon, 2006-11-27 at 17:21 -0800, Matt Leininger wrote: > On Mon, 2006-11-27 at 16:45 -0800, Matt Leininger wrote: > > Has anyone testing OMPI's alltoall at > 2000 MPI tasks? I'm seeing each > > MPI task eat up > 1GB of memory (just for OMPI - not the app). > > I gathered some more data using the alltoall benchmark in mpiBench. > mpiBench is pretty smart about how large its buffers are. I set it to > use <= 100MB. > > num nodes num MPI tasks system mem mpibench buffer mem > 128 1024 1 GB 65 MB > 160 1280 1.2 GB 82 MB > 192 1536 1.4 GB 98 MB > 224 1792 1.6 GB 57 MB > 256 2048 1.6-1.8 GB < 100 MB > > The 256 node run was killed by the OOM for using too much memory. For > all these tests the OMPI alltoall is using 1 GB or more of system > memory. I know LANL is looking into optimized alltoall, but is anyone > looking into the scalability of the memory footprint? >
Can you "cat /proc/pid/smaps" when running the MPI job? Ollie
