On Jan 27, 2012, at 6:36 PM, Mark F. Adams wrote: > > On Jan 27, 2012, at 6:58 PM, Jed Brown wrote: > >> On Fri, Jan 27, 2012 at 17:48, Matthew Knepley <knepley at gmail.com> wrote: >> Is now the right time. Shouldn't we wait until MPI's replacement is >> working and do things with that model? >> >> I'm laughing. Am I supposed to be? >> >> I'm laughing too. >> >> There isn't going to be a replacement for MPI until the smart people that >> understand parallel programming, performance, and libraries start working on >> something other than MPI. But most of those people are on the MPI Forum, >> trying to improve MPI. Now we need a good model for threads, and that might >> not be based on MPI, but it sure looks like the large-scale >> distributed-memory model will be MPI for the foreseeable future. >> > > I don't think its a matter of smart people not having worked on this, they > have IMO, its just a hard problem.
I disagree; it is not necessarily hard, it is just that the non-MPI people are pretty fucking stupid. Barry > >> >> As for sources of parallel errors, yes, it's somewhat tricky, but as long as >> the model is to get a sub-object out of a bigger one (submatrix, coarse >> level, etc), I think we can manage it. At any particular time, the user >> should still be looking at essentially single-comm collections of objects, >> but not all processes will end up being called in every context. >
