Configurable-Kernel-Parameter Help: semmns

semmns

semmns defines the system-wide maximum number of individual IPC semaphores that can be allocated for users.

Acceptable Values:

Minimum
2
Maximum
Memory limited
Default
128

Specify integer value or use integer formula expression. For more information, see Specifying Parameter Values.

Description

semmns defines the system-wide maximum total number of individual semaphores that can be made available to system users.

When the free-space map shows that there are not enough contiguous semaphore slots in the semaphore area of shared memory to satisfy a semget() request, semget() returns a ENOSPC error. This error can occur even though there may be enough free semaphores slots, but they are not contiguous.

Related Parameters

semmsl is the value of the maximum number of semaphores that can be associated with a semaphore ID. The value of semmsl is set at 500 and is not configurable.

Additional Information