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

[Jack Poulson]

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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.alcf.anl.gov/pipermail/llvm-bgq-discuss/attachments/20130301/f08f9608/attachment.html>