Pending Send Operations
TotalView displays each pending send operations in the Pending sends list.
MPICH does not normally keep information about pending send operations. However, when you configure MPICH, you can tell it to maintain a list of them. Start your program under TotalView's control and use mpirun's -ksq, or -KeepSendQueue if MPICH to see this kept.
Depending on the device for which MPICH was configured, blocking send operations may or may not be visible. However, if they are not displayed, you can see that these operations occurred because the call is in the stack backtrace.
If you attach to an MPI program that is not maintaining send queue information, TotalView displays the following message:
Pending sends : no information available