cpuonoff(ADM)

cpuonoff -- activate, inactivate or display processor state

Syntax

cpuonoff [ -c ] [ -a cpu ] [ -d cpu ] [ -i cpu ]

Description

cpuonoff is a utility which allows processors to be activated or inactivated without the need to reconfigure the kernel. A processor that has been inactivated will not run any processes but is still capable of processing interrupts. cpuonoff will also display the current state of each processor.

cpuonoff will not allow the base processor, CPU1, to be made inactive.

root permission is required to run cpuonoff.

The options are as follows:

-c: displays the current state of all processors in the form: cpu 1: active/inactive
...
cpu n: active/inactive
-a cpu: activates cpu where cpu is an integer
-d cpu: inactivates cpu where cpu is an integer
-i cpu: inactivates cpu where cpu is an integer

Exit values

cpuonoff exits with 0 upon successful completion. It exits with 1 if an error occurs.

Diagnostics

Messages may include the following:

cpuonoff: invalid CPU specified: The argument specifying a processor must be numeric.
cpuonoff: cannot specify negative CPU: The argument specifying a processor must be a positive integer.
cpuonoff: CPU specified exceeds number of CPUs installed: The specified processor does not exist or has not been serialized.
cpuonoff: can't open device: The required device node device is missing. Run idmknod(ADM) to recreate any missing device nodes.
cpuonoff: cannot determine number of processors: The kernel cannot determine the number of processors installed and serialized.
cpuonoff: malloc for procdata failed: cpuonoff could not malloc required memory for its internal work area.
cpuonoff: cannot determine processor_data: cpuonoff could not read the relevant processor data from the kernel.
cpuonoff: incorrect option usage: Options given to cpuonoff must be one of -a, -i or -c.
cpuonoff: cannot modify state of CPU 1: The state of the base processor cannot be modified. It always remains in the active state.
cpuonoff: cannot inactivate CPUnum: cpuonoff failed to inactivate the specified processor, number num.
cpuonoff: cannot activate CPUnum: cpuonoff failed to activate the specified processor, number num.

Warnings

This command numbers processors beginning with 1. The similar psrinfo(ADM) and psradm(ADM) commands number processors beginning with 0. The two sets of commands can be used together, but be aware of the numbering sequence difference.

If a processor running processes locked onto it is made inactive, then the locked processes will be suspended until the processor is once again activated.

Files

/etc/cpuonoff: command

Standards conformance

cpuonoff is not part of any currently supported standard; it is an extension of AT&T System V provided by the Santa Cruz Operation, Inc.