[Beowulf] MS HPC... Oh dear...
ashley at quadrics.com
Wed Jun 14 02:30:14 PDT 2006
On Tue, 2006-06-13 at 20:53 +0100, James Cownie wrote:
> > Nothing. Unfortunately most folks use statically linked binaries for
> > MPI, so .so's are not a factor. I could be wrong, and maybe there
> > is a
> > way to get statically linked binaries to respect LD_PRELOAD or
> > LD_LIBRARY_PATH, but I am not aware of it.
> > More to the point, this dynamic binding allows you to write to the
> > API,
> > present a consistent ABI, and handle the hardware details elsewhere
> > in a
> > driver which can be linked in by the .so/.dll/.eieio method at
> > runtime.
> > Which is about the complexity that most end users/customers want.
> As I understand it this is what Intel's MPI (for LInux) does, so that
> you can choose the underlying hardware transport without relinking
> your code.
I'd read this differently, I thought Joe was talking about the advantage
of dynamic libraries over static ones, The idea being that as long as
it's mpich2 based (or at least uses the mpich2 header file) anybody can
create a DLL which is binary compatible and the app won't notice. For
this to work of course Microsoft would probably need to release their
source changes to mpich2 under the BSD Licence.
Intel use a dynamic layer underneath or inside MPI which allows a single
MPI DLL to make choices about which interconnect it uses at run time.
Greg - Yes you did leave some out.
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