sema

sema enables or disables System V IPC semaphores support in kernel at system boot time (Series 700 only).

Acceptable Values:

Minimum
0 (exclude System V IPC semaphore code from kernel)
Maximum
1 (include System V IPC semaphore code in kernel)
Default
1

Specify integer value of 0 or 1. For more information, see Specifying Parameter Values.

Description

sema determines whether the code for System V IPC semaphore is to be included in the kernel at system boot time (Series 700 systems only).

sema = 1
Code is included in the kernel (enable IPC shared memory).

sema = 0
Code is not included in the kernel (disable IPC shared memory).

Series 800 systems: IPC shared memory is always enabled in the kernel.

Series 700 systems: If shmem is set to zero, all other IPC shared memory parameters are ignored.

Starbase graphics library and some other HP-UX subsystems use semaphores. Disable only if you are certain that no applications on your system depend on System V IPC semaphores.

If sema is zero, any program that uses semget() or semop() system calls, will return a SIGSYS signal.

Related Parameters

If sema is not set, all other semaphore kernel parameters are ignored.

Additional Information