This file contains 4 numbers defining limits for System V IPC semaphores. These fields are, in order:

  • SEMMSL - the maximum number of semaphores per semaphore set.
  • SEMMNS - a system-wide limit on the number of semaphores in all semaphore sets.
  • SEMOPM - the maximum number of operations that may be specified in a semop(2) call.
  • SEMMNI - a system-wide limit on the maximum number of semaphore identifiers.

The default values are "250 32000 32 128".