Hi, Let's say I have 20 ranks. They all call MPI_Win_create_dynamic to create a window. Then, every rank attach a buffer with MPI_Win_attach to their window. Then, rank 3 calls MPI_Put to put, say, some data on the window of rank 99. Rank 3 can then rely on MPI_Win_test to verify the completion of the operation via the flag (or it can use MPI_Rput + MPI_Test). Is there a way for rank 99 to know that its window (its buffer) contains new data ?