On Nov 24, 2011, at 1:50 PM, Jed Brown wrote:
> On Thu, Nov 24, 2011 at 13:27, Barry Smith <bsmith at mcs.anl.gov> wrote:
> Programming with pthreads is library based programming. There is an API
> that you call in your language with function calls from your code to do
> stuff, it is in no way an extension to the language. Now there are some
> issues with the pthread API and I am not advocating it but just using it as
> an example of how flexible parallel programming can be done on-node using a
> purely library based system.
>
> But you don't want "MPI+pthreadsish" because of how it's spelled or because
> it's complicated (two abstractions that don't fit together as well as they
> could)?
Jed,
Come on, stop being silly; it has nothing to do with the fact that it is
MPI+something. It is because it is too complicated and hard to use and both
MPI and pthreads have bad limitations (for pthreads it is the fact that
pthreads does not have a good way of waking up many pthreads together to do
something, for MPI it is due to point to point and one sided do not allow
proper scheduling of communication at the low level).
> What about a library that was implemented in terms of MPI and pthreads, but
> gave you a more consistent abstraction?
That would be fine, even great. I just don't believe that either of them are
the right base to build on.
You sound a bit like Jack telling me in 1994 that I should write PETSc on
top of Scalapack.
Barry
