General Kernel Parameters

This section discusses general kernel parameters, including those for the following:

• Shared memory

• Processes

• Signals

• Profiling/debugging

• System

Shared Memory

Sysctl Prefix: kernel

/proc Prefix: /proc/sys/kernel/

Parameter	Description
sem	Semaphore values
msgmnb	Maximum message queue in bytes
msgmni	Maximum allowed message queue identifiers
msgmax	Maximum message size in bytes
shmmni	Number of shared segments system-wide
shmall	Shared memory system-wide in pages
shmmax	Shared segment size in bytes

Processes

Sysctl Prefix: kernel

/proc Prefix: /proc/sys/kernel/

Parameter	Description
tHRead_max	Maximum threads allowed in the system

Signals

Sysctl Prefix: kernel

/proc Prefix: /proc/sys/kernel/

Parameter	Description
rtsig-max	Maximum real-time signals
rtsig-nr	Number of currently queued real-time signals

Profiling/Debugging

Sysctl Prefix: kernel

/proc Prefix: /proc/sys/kernel/

Parameter	Description
sysrq	System trace request
printk	Printk values

The printk parameter has four fields: console_loglevel, default_message_ loglevel, minimum_console_level, and default_console_level. Messages with a higher priority than console_loglevel are printed to the console. Messages without an explicit priority are printed with default_message_loglevel priority. The minimum (highest) value to which console_loglevel can be set is determined by the minimum_console_level parameter. The default_console_loglevel is the default value for console_loglevel.

System

Sysctl Prefix: kernel

/proc Prefix: /proc/sys/kernel/

Parameter	Description
domainname	Domain name
hostname	Host name
ostype	Operating system type
osrelease	Operating system release
version	Kernel version
real-root-dev	Real root device partition