MPI layer: assert that Charm does not require msg ordering (#3594)

Co-authored-by: Ronak Buch <rabuch2@illinois.edu>
charmplusplus · Apr 22, 2022 · cb4d760 · cb4d760
1 parent 243d32d
commit cb4d760
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/src/arch/mpi/machine.C b/src/arch/mpi/machine.C
@@ -1423,9 +1423,16 @@ void LrtsInit(int *argc, char ***argv, int *numNodes, int *myNodeID) {
 
     largc = *argc;
     largv = *argv;
+
     if(!CharmLibInterOperate || userDrivenMode) {
-      MPI_Comm_dup(MPI_COMM_WORLD, &charmComm);
+      /* Create our communicator, with info hints (such as us not requiring
+       * message ordering) to enable possible MPI runtime optimizations. */
+      MPI_Info hints;
+      MPI_Info_create(&hints);
+      MPI_Info_set(hints, "mpi_assert_allow_overtaking", "true");
+      MPI_Comm_dup_with_info(MPI_COMM_WORLD, hints, &charmComm);
     }
+
     MPI_Comm_size(charmComm, numNodes);
     MPI_Comm_rank(charmComm, myNodeID);