On Jan 27, 2012, at 8:22 PM, Barry Smith wrote: > > 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. >
It is not hard, intellectually intriguing, fundable, and smart people won't do it. What am I missing? > 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. >> > >
