Parameter 

Default 

Description 

Message Queue 

msginfo_msgmap

100 

Number of entries in the message map 

msginfo_msgmax

2048 

Maximum message size  

msginfo_msgmnb

4096 

Maximum bytes on queue  

msginfo_msgmni

50 

Number of message queue identifiers  

msginfo_msgssz

8 

Segment size of a message (should be a multiple of the word size) 

msginfo_msgtql

40

Number of system message headers  

msginfo_msgseg

1024

Number of message segments (must be < 32768) 

Semaphore Facility 

seminfo_semmap

10

Number of entries in the semaphore map  

seminfo_semmni

10

Number of semaphore identifiers  

seminfo_semmns

60

Number of semaphores in the system  

seminfo_semmnu

30

Number of processes using the undo facility

seminfo_semmsl

25

Maximum number of semaphores, per id

seminfo_semopm

10

Maximum number of operations, per semaphore call  

seminfo_semume

10

Maximum number of undo structures per process

Note: The total number of undo structures allocated in the system is:

seminfo_semmnu * seminfo_semume

seminfo_semvmx

32767

Semaphore maximum value 

seminfo_semaem

16384

Maximum value for adjustment on exit 

Shared Memory 

shminfo_shmmax

1048576

Maximum shared memory segment size  

shminfo_shmmin

1

Minimum shared memory segment size  

shminfo_shmmni

100

Number of shared memory identifiers  

shminfo_shmseg

6

Segments, per process