[O-MPI users] Re: [Beowulf] Alternative to MPI ABI

Joachim Worringen joachim at ccrl-nece.de
Tue Mar 29 23:36:15 PST 2005


Greg Lindahl wrote:
> On Sat, Mar 26, 2005 at 06:47:41AM -0500, Jeff Squyres wrote:
>>I guess I don't understand your reluctance to accept a MorphMPI-like 
>>solution:
> 
> You have repeated your original MorphMPI attributes. I responded to
> them, and I don't see any sign that you've read my response. This is
> not the way discussions are usually held.

Jeff explained very well the problems he sees with your additional 
F77-like-C-API (which, BTW, is largely realized in MPICH as all opaque 
types there are integer handles): two interfaces means two mpi.h and two 
libraries to maintain. I doubt that any implementor is keen on this.

Instead, a layer on top would be easier, and not unrealistic to 
maintain: a serious MPI implementation will rarely (never!?) change its 
mpi.h/mpif.h. We (for NEC's MPI implemenation across all platforms) 
didn't do so for 5 years when we completed the full MPI-2 functionality. 
And even before, we only added things, but didn't change existing 
definitions.

  Joachim

-- 
Joachim Worringen - NEC C&C research lab St.Augustin
fon +49-2241-9252.20 - fax .99 - http://www.ccrl-nece.de



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