Maximum value a semaphore can be set to.

Unsigned short

32,767

1 to 65,535

No

None

When the default value is not enough. Generally changed at the recommendation of software vendors. No error messages are displayed when the maximum value is exceeded. The application sees a return code of ERANGE from a semop(2) call.

Unstable

Maximum number of System V semaphores per semaphore identifier.

Signed integer

25

1 to MAXINT

No

The amount of space that could possibly be consumed by the semaphores and their supporting data structures is compared to 25% of the kernel memory available at the time the module is first loaded. If the memory threshold is exceeded, the module refuses to load and the semaphore facility is not available.

When the default value is not enough. Generally changed at the recommendation of software vendors. No error messages are displayed when an attempt is made to create more semaphores in a set than are currently configured. The application sees a return code of EINVAL from a semget(2) call.

Unstable

Maximum number of System V semaphore operations per semop(2) call. This parameter refers to the number of sembufs in the sops array that is provided to the semop() system call.

Signed integer

10

1 to MAXINT

No

The amount of space that could possibly be consumed by the semaphores and their supporting data structures is compared to 25% of the kernel memory available at the time the module is first loaded. If the memory threshold is exceeded, the module refuses to load and the semaphore facility is not available.

When the default value is not enough. Generally changed at the recommendation of software vendors. No error messages are displayed when an attempt is made to perform more semaphore operations in a single semop call than are currently allowed. The application sees a return code of E2BIG from a semop() call.

Unstable

Total number of undo structures supported by the System V semaphore system.

Signed integer

30

1 to MAXINT

No

The amount of space that could possibly be consumed by the semaphores and their supporting data structures is compared to 25% of the kernel memory available at the time the module is first loaded. If the memory threshold is exceeded, the module refuses to load and the semaphore facility is not available.

When the default value is not enough. Generally changed at the recommendation of software vendors. No error message is displayed when an attempt is made to perform more undo operations than are currently configured. The application sees a return value of ENOSPC from a semop(2) call when the system runs out of undo structures.

Unstable

For information, see "semsys:seminfo_semmnu".

Maximum number of System V semaphore undo structures that can be used by any one process.

Signed integer

10

1 to MAXINT

No

The amount of space that could possibly be consumed by the semaphores and their supporting data structures is compared to 25% of the kernel memory available at the time the module is first loaded. If the memory threshold is exceeded, the module refuses to load and the semaphore facility is not available.

When the default value is not enough. Generally changed at the recommendation of software vendors. No error messages are displayed when an attempt is made to perform more undo operations than are currently configured. The application sees a return code of EINVAL from a semop(2) call.

Unstable

Maximum value that a semaphore's value in an undo structure can be set to.

Unsigned short

16,384

1 to 65,535

No

None

When the default value is not enough. Generally changed at the recommendation of software vendors. No error messages are displayed when an attempt is made to perform more undo operations than are currently configured. The application sees a return code of EINVAL from a semop(2) call.

Unstable