Re: [OMPI devel] RFC: [slightly] Optimize Fortran MPI_SEND / MPI_RECV

2009-02-07 Thread Jeff Squyres
On Feb 4, 2009, at 6:05 PM, Eugene Loh wrote: - Remove a function call from the critical performance path; possibly save a little latency The only "benefit" is "possibly a little"? This is not at all compelling. Is the hoped-for benefit measurable? I assume a pingpong latency test ove

[OMPI devel] meeting @Cisco on Wednesday

2009-02-07 Thread Jeff Squyres
I've updated the wiki with the specific meeting location -- we're in a different building than the MPI Forum meeting (right across the street). For those of you who were there, it's the same conference room that we used for the RTE meeting in December: https://svn.open-mpi.org/trac/omp

Re: [OMPI devel] RFC: [slightly] Optimize Fortran MPI_SEND / MPI_RECV

2009-02-07 Thread Brian W. Barrett
On Sat, 7 Feb 2009, Jeff Squyres wrote: End result: I guess I'm a little surprised that the difference is that clear -- does a function call really take 10ns? I'm also surprised that the layered C version has significantly more jitter than the non-layered version; I can't really explain that.

Re: [OMPI devel] RFC: [slightly] Optimize Fortran MPI_SEND / MPI_RECV

2009-02-07 Thread Jeff Squyres
On Feb 7, 2009, at 12:23 PM, Brian W. Barrett wrote: End result: I guess I'm a little surprised that the difference is that clear -- does a function call really take 10ns? I'm also surprised that the layered C version has significantly more jitter than the non-layered version; I can't real