[mpich-discuss] low performance in an asynchronous, mixed MPI/pthreads app

[Geoffrey Irving]

On Mon, Jan 7, 2013 at 11:09 PM, Geoffrey Irving <irving at naml.us> wrote:
> On Mon, Jan 7, 2013 at 11:39 AM, Darius Buntinas <buntinas at mcs.anl.gov> wrote:
>> Hi Geoff,
>>
>> Is it possible for you to try this with fewer worker threads per node (leaving some idle cores on each node)?
>
> Yes, this should have been an easy thing to try, but it crashed due to
> passing a 0 pointer to MPI.  That may indicate that I ran out of
> memory and an unchecked malloc failed.  I'll track that down and
> retry.

Here are results:

    1 progress thread, 1 comm thread, 4 workers: 169.9694 s
    1 progress thread, 1 comm thread, 3 workers: 160.2020 s

This is using MPI_THREAD_MULTIPLE.

Geoffrey