On Jan 28, 2012, at 1:10 PM, Barry Smith wrote: > > On Jan 28, 2012, at 10:59 AM, Matthew Knepley wrote: > >> On Sat, Jan 28, 2012 at 8:00 AM, Mark F. Adams <mark.adams at columbia.edu> >> wrote: >> >> 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? >> >> I think Barry's point is that this is another case where, no matter how >> smart or motivated you are, if you start >> out with a bad design decision in the beginning, and refuse to change it for >> whatever reason, you will not >> succeed. > > Matt's got it! The slight difference is that I submit is that people who > "start out with a bad design decision in the beginning, and refuse to change > it for whatever reason" are fundamentally stupid even though they may be > considered by most measures to be smart. To me the "bad design decisions" > are so blindly obviously wrong it is hard for me to label the people who > "refuse to change it for whatever reason," anything but stupid, what other > phrase should I use "smart in many ways but blindly stupid in this one > regard?" >
Ok, first you two have changed the question (is this a Chicago thing?) -- why have "smart" people not done something that is "not hard" and an obviously important and even a hot ($) topic (for decades)? You are implying some massive systemic market failure. That said, I'm willing to go with the flow. There are hundreds of parallel programming languages out there (http://en.wikipedia.org/wiki/List_of_concurrent_and_parallel_programming_languages). You are implying that they are all done by rigid and narrow minded thinkers. All of them. Morons. Really? > > Barry > > >> >> Matt >> >>> 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. >>>> >>> >>> >> >> >> >> >> -- >> What most experimenters take for granted before they begin their experiments >> is infinitely more interesting than any results to which their experiments >> lead. >> -- Norbert Wiener > >
