Can you resend without the awful HTML punctuation? =3D=3D is not easy to parse. Jeff Sent from my iPhone
On Jul 14, 2014, at 2:15 PM, "Balaji, Pavan" <[email protected]> wrote:
P0: Win_lock(P1) Put(X, 1) Win_unlock(P1) MPI_Send(P1)
P1: MPI_Recv(P0) assert(X =3D=3D 1)
If the above is correct, shouldn=92t there be a memory read barrier on P1 s= omewhere? Since P1 is not making any RMA calls, I=92d assume that=92ll nee= d to somehow come from the lock and unlock operations. That is, the MPI im= plementation will need to do an active message in Win_lock and Win_unlock f= orcing a memory barrier at the target. Assuming that=92s correct, I'll hav= e to send out a lock packet even if the user gave the MPI_MODE_NOCHECK hint= , for memory consistency reasons. That sounds awful, so I=92m really hopin= g that I missed something in the standard which will say I don=92t need to = do all this.
Note that all this active message problem will go away if I need P1 to do a= lock/unlock to itself in order to access X.
Thanks,
=97 Pavan
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