If on average the MPI processes are stuck in their last MPI call for more than this threshold, then a

GLOBAL:DEADLOCK:NO_PROGRESS

warning is generated. This is a sign of a load imbalance or a deadlock which cannot be detected because at least one process polls for progress instead of blocking inside an MPI call.

As usual, the value may also be specified with units,

1m

for one minute, for example.