[Llvm-bgq-discuss] Details behind MPI wrapper for bgclang++

[Jeff Hammond]

This is BGQ @ ALCF, right?  Might be MPI calls inside of Darshan.  I
disable it because of issues like this.

I think my ~/.soft is world-readable.  Use the @mpi-wrappers script
and try to verify that you aren't getting Darshan in your build.

Jeff

On Fri, Mar 1, 2013 at 11:16 AM, Jack Poulson <jack.poulson at gmail.com> wrote:
> On Thu, Feb 28, 2013 at 10:15 PM, Hal Finkel <hfinkel at anl.gov> wrote:
>>
>>
>> Not a problem! Thanks for being a beta tester :) I've updated the
>> installed libc++ libraries to use CLOCK_REALTIME instead of CLOCK_MONOTONIC.
>> Please try again.
>>
>>  -Hal
>>
>
> One more problem taken care of it seems. Unfortunately my program now
> segfaults in an MPI_Gather call (and the trace still seems a bit corrupted,
> see core.13). There is really only one instance in my program where
> MPI_Gather is called, and it looks like this:
>
> vector<int> myCoords(d), coords(1);
> // <fill myCoords here>
> if( commRank == 0 )
>     coords.resize( d*commSize );
> MPI_Gather( &myCoords[0], d, MPI_INT, &coords[0], d, MPI_INT, 0, comm );
>
> In the above snippet, 'd' is the dimension of the domain, which is two for
> the executable in question, and space for storing every process's
> coordinates is only allocated on the root process. This is pretty
> straightforward MPI in my opinion, so I am skeptical that I have a bug here.
>
> Jack



-- 
Jeff Hammond
Argonne Leadership Computing Facility
University of Chicago Computation Institute
jhammond at alcf.anl.gov / (630) 252-5381
http://www.linkedin.com/in/jeffhammond
https://wiki.alcf.anl.gov/parts/index.php/User:Jhammond