The semume parameter specifies the maximum number of ''undo'' entries per undo structure. An undo structure, which is set up on a per-process basis, keeps track of process operations on semaphores so that the operations may be ''undone'' if it terminates abnormally. Each undo entry represents a semaphore that has been modified with the UNDO flag specified in the semop(2) system call.
This parameter is specified in /var/sysgen/mtune/sem.