June 22, 2008 CPUCTL 8

### NAME

cpuctl - program to control CPUs

### SYNOPSIS

cpuctl command [arguments]

### DESCRIPTION

The cpuctl command can be used to control and inspect the state of CPUs in the system.

The first argument, command, specifies the action to take. Valid commands are:

identify cpu
  Output information on the specified CPU's features and capabilities. Not available on all architectures.

list
  For each CPU in the system, display the current state and time of the last state change.

offline cpuno
  Set the specified CPU off line.

  Unbound LWPs (lightweight processes) will not be executed on the CPU while it is off line. Bound LWPs will continue to be executed on the CPU, and device interrupts routed to the CPU will continue to be handled. A future release of the system may allow device interrupts to be re-routed away from individual CPUs.

  At least one CPU in the system must remain on line.

online cpuno
  Set the specified CPU on line, making it available to run unbound LWPs.

### FILES

```/dev/cpuctl`
  control device

### SEE ALSO

psrset(8), schedctl(8)

### HISTORY

The cpuctl command first appeared in NetBSD5.0.