Thanks. I understand that this isn't an easy issue. We are trying to use MPI-3 shared memory windows internally with PSCW-like synchronization and I am inclined to just give up and use x86 intrinsics to do what I know is sufficient for our processors and compilers, just to make it easy (and fast). Jeff On Wed, Jan 28, 2015 at 1:43 PM, William Gropp <[email protected]> wrote:
That’s a harder topic and I wanted to think more about it. Here are the two issues with which I am most concerned:
1) We are defining the interaction of MPI with stuff that happens outside of MPI, in the programming language. Yes, we always sort of did, but this is in an area where many skilled people have made mistakes, and the likelyhood of an error is much higher. The lack of precision in these discussions reinforces my concern.
2) We are not considering the potential overhead that requiring other than a small set of RMA synchronization routines to guarantee some shared memory synchronization. The sense that I get is that the Forum is unconcerned about this, which I think is a serious mistake, and one for which I have yet to see a compelling use case.
Bill
On Jan 28, 2015, at 7:46 PM, Jeff Hammond <[email protected]> wrote:
Fine, but it would be helpful if you would respond to my comments about allowing point-to-point _synchronization_ on shared memory using PSCW, since those were the more germane ones anyways.
_______________________________________________ mpiwg-rma mailing list [email protected] http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-rma
-- Jeff Hammond [email protected] http://jeffhammond.github.io/