Hmm. There was a reason we added that. I think this had to do with separating collectives from one "epoch" from those of another, so that no one does anything like this: P0 P1 ------------------- ------------------- MPI_Ibcast() MPI_Comm_validate() MPI_Comm_validate() . MPI_Ibcast() MPI_Wait() MPI_Wait() Maybe we should say that validate completes-with-error all outstanding collective operations. But in that case if the user spans a collective across a validate the collective may complete successfully at one process (e.g., root of bcast) and complete-with-an-error on another, but validate() would show that no processes have failed (no process failures would normally indicate that the bcast completed successfully). I guess we can call this a user error, and just say don't do that. -d On Dec 20, 2011, at 9:03 AM, Josh Hursey wrote:

In 17.7.1 the proposal states: "All collective communication operations initiated before the call to MPI_COMM_VALIDATE must also complete before it is called, and no collective calls may be initiated until it has completed."

Considering the case where FailHandlers are used in the 'ALL' operating mode. In this mode, a user may want to call validate in all of the FailHanlders to synchronize them. But if the FailHandler was triggered out of a collective operation over a communicator that does -not- include the failed process then the user cannot write a correct program (since they cannot cancel, and may not be able to complete the collective operation).

My suggestion is that we remove this sentence. Do folks have a problem with this?

Thanks, Josh

-- Joshua Hursey Postdoctoral Research Associate Oak Ridge National Laboratory http://users.nccs.gov/~jjhursey _______________________________________________ mpi3-ft mailing list [email protected] http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-ft