Changing Tunable Parameter Values

Tunable parameters are defined by symbolic names within the ChorusOS operating system components. Symbolic names include dots (.), to maintain compatibility with previous releases of the ChorusOS operating system. An example of a symbolic name is kern.exec.maxCpuNumber, which is a tunable.

The definition of a tunable parameter includes the definition of a default value for this parameter. Integer values of tunable parameters are expressed either as integers or as hexadecimal numbers.

To change the value of a tunable parameter, use:

% configurator -set tunable_name=value

For example, to reconfigure the microkernel to enable the creation of 300 threads:

% configurator -set kern.exec.maxThreadNumber=300

You can check the value of a tunable parameter as follows:

% configurator -list tunable tunable_name

You can list the values of all the microkernel executable tunables as follows:

% configurator -list tunable kern.exec.*

The output lists the microkernel executable tunables and their values:

kern.exec.maxCpuNumber:int='1'
kern.exec.maxActorNumber:int='64'
kern.exec.maxThreadNumber:int='300'
kern.exec.bgStackSiz:int='0x1000'
kern.exec.dflSysStackSize:int='0x3000'
kern.exec.dflUsrStackSize:int='0x4000'
kern.exec.dblFltStackSize:int='0x800'
kern.exec.intrStackSize:int='0x3000'

You can list a tunable parameter in greater detail with the -info option:

% configurator -info tunable tunable_name 

The tunable, its value and its description are displayed:

% configurator -info tunable kern.lap.*

kern.lap.maxLapBindNumber:int='256'
Description: Maximum number of bind LAPs 

kern.lap.maxLapSafeNumber:int='128'
Description: Maximum number of safe LAPs