Oracle Solaris Tunable Parameters Reference Manual

semsys:seminfo_semmnu (Solaris 9 Releases)

Removed in the Solaris 10 release.

Description

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

Data Type

Signed integer

Default

30

Range

1 to MAXINT

Dynamic?

No

Validation

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 to Change

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.

Commitment Level

Unstable