About Pending Send Operations

TotalView displays each pending send operation in the Pending sends list.

MPICH does not normally keep information about pending send operations. If you want to see them, start your program under TotalView control and use the mpirun –ksq or –KeepSendQueue command.

Depending on the device for which MPICH was configured, blocking send operations may or may not be visible. However, if TotalView doesn’t display them, you can see that these operations occurred because the call is in the stack backtrace.

If you attach to an MPI program that isn’t maintaining send queue information, TotalView displays the following message:

Pending sends : no information available