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

[Jeff Hammond]

https://www.alcf.anl.gov/resource-guides/darshan doesn't touch the MPI
source.  It's an IO profiling library that is interposed by the MPI
wrappers.  If you don't see , then it might not be included.

As you know, I'm at SIAM, but I'll try to look at this next week
during MiraCon (which I know you are not attending).

Jeff

On Fri, Mar 1, 2013 at 1:52 PM, Jack Poulson <jack.poulson at gmail.com> wrote:
> Hi Jeff,
>
> Yes, this is on Vesta. There doesn't seem to be anything in your .soft file
> different from mine, other than you specifying the Nov 2012 IBM compilers.
>
> Is it possible for me to browse through the current source for the BGQ MPICH
> modifications?
>
> Jack
>
>
> On Fri, Mar 1, 2013 at 10:30 AM, Jeff Hammond <jhammond at alcf.anl.gov> wrote:
>>
>> 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
>
>



-- 
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