[petsc-users] PETSc and AMPI

[Barry Smith]

> On Feb 2, 2015, at 11:27 PM, Jed Brown <jed at jedbrown.org> wrote:
> 
> Barry Smith <bsmith at mcs.anl.gov> writes:
>>   Way more complicated then needed :-)
> 
> Heh, I was just spelling it out.
> 
>>> If AMPI creates threads dynamically,
>> 
>>  How could it possibly create threads dynamically and still be
>>  running in the MPI 1 model of a consistent number of MPI "processes"
>>  at all times?
> 
> I don't know, but it seems plausible that it would over-subscribe

  It definitely over-subscribes. 

> and
> then dynamically migrate MPI ranks around.

   Yes "cheating" with out global data structures won't work if it migrates the MPI ranks around but I can't image how it would do that.