Linux kernel parameter semaphore semaphore settings

Current system semaphore limit:

# Ipcs-ls

--semaphore limits--–

Max number of arrays = 128

Max semaphores per array = 250

Max semaphores system wide = 32000

Max Ops per semop call = 100

Semmsl

• Meaning: The maximum number of semaphores in each semaphore set

• Setting: Min 250, System recommended for processes parameter set to PROCESSES+10

Semmni

• Meaning: Maximum number of semaphore set for Linux system

• Setting: Minimum 128

Semmns

• Meaning: Maximum number of semaphores in a Linux system

• Setting: Minimum 32000;SEMMSL * Semmni

semopm

• Meaning: Maximum number of semaphores allowed for SEMOP system calls

• Set: at least 100; or equal to SEMMSL

To view semaphore settings: Cat/proc/sys/kernel/sem

ORDER:SEMMSL, Semmns, SEMOPM, Semmni

# Cat/proc/sys/kernel/sem

250 32000 100 128

Modify:

Sysctl-w kernel.sem= "250 32000 100 128″

echo "kernel.sem=250 32000 100 128″>>/etc/sysctl.conf

Linux kernel parameter semaphore semaphore settings