When running the ch_p4 device with SMP support (-comm=shared),
you may occasionally see the message
"p1_13043: p4_error: OOPS: semop lock failed"To fix this, try running the script cleanipcs that is included with MPICH. You can also use the command ipcs to list the shared memory and semaphore resources that are in use on a node. This can help you track down resources that are held by a different user that are preventing your MPI program from running.