semvmx

semvmx specifies the maximum possible semaphore value.

Acceptable Values:

Minimum
1
Maximum
65535
Default
32767

Specify integer value. For more information, see Specifying Parameter Values.

Description

semvmx specifies the maximum value a semaphore can have. This limit must not exceed the largest number that can be stored in a 16-bit unsigned integer (65535) or undetectable semaphore overflows can occur.

Any semop() system call that tries to increment a semaphore value to greater than semvmx returns an ERANGE error. If semvmx is greater than 65535, semaphore values can overflow without being detected.

semop specifies the maximum number of semaphores that can be changed using a single system call. This value is specified in the file /usr/include/sys/sem.h.

Related Parameters

semaem must be less than or equal to semvmx

Additional Information