ncallout

ncallout specifies the maximum number of timeouts that can be scheduled by the kernel at any given time.

Acceptable Values:

Minimum

6

Maximum

Memory limited

Default

16+Nproc+USING_ARRAY_SIZE+SERVING_ARRAY_SIZE

Specify integer value or use integer formula expression. For more information, see Specifying Parameter Values.

Description

ncallout specifies the maximum number of timeouts that can be scheduled by the kernel at any given time. Timeouts are used by:

• alarm() system call,
• setitimer() system call,
• select() system call,
• drivers,
• uucp processes,
• process scheduling.

When the system exceeds the timeout limit, it prints the following fatal error to the system console:

panic: timeout table overflow

Related Parameters

If the value of nproc is increased, ncallout should be increased proportionately. A general rule is that one callout per process should be allowed unless you have processes that use multiple callouts.

Additional Information

• Overview of Miscellaneous Parameters
• List of parameters
• Browse configurable kernel parameters help