---
name: "chcpu"
section: "8"
platform: "linux"
package: "util-linux"
version: "2.42.4-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/chcpu"
---

# chcpu(8)

configure CPUs

## NAME

chcpu - configure CPUs

## SYNOPSIS

**chcpu** **-c**\|**-d**\|**-e**\|**-g** *cpu-list*

**chcpu** **-p** *mode*

**chcpu** **-r**\|**-h**\|**-V**

## DESCRIPTION

**chcpu** can modify the state of CPUs. It can enable or disable CPUs, scan for new CPUs, change the CPU dispatching *mode* of the underlying hypervisor, and request CPUs from the hypervisor (configure) or return CPUs to the hypervisor (deconfigure).

Some options have a *cpu-list* argument. Use this argument to specify a comma-separated list of CPUs. The list can contain individual CPU addresses or ranges of addresses. For example, **0,5,7,9-11** makes the command applicable to the CPUs with the addresses 0, 5, 7, 9, 10, and 11.

## OPTIONS

- **-c**, **--configure** *cpu-list*

  Configure the specified CPUs. Configuring a CPU means that the hypervisor takes a CPU from the CPU pool and assigns it to the virtual hardware on which your kernel runs.

- **-d**, **--disable** *cpu-list*

  Disable the specified CPUs. Disabling a CPU means that the kernel sets it offline.

- **-e**, **--enable** *cpu-list*

  Enable the specified CPUs. Enabling a CPU means that the kernel sets it online. A CPU must be configured, see **-c**, before it can be enabled.

- **-g**, **--deconfigure** *cpu-list*

  Deconfigure the specified CPUs. Deconfiguring a CPU means that the hypervisor removes the CPU from the virtual hardware on which the Linux instance runs and returns it to the CPU pool. A CPU must be offline, see **-d**, before it can be deconfigured.

  **chcpu -g** is not supported on IBM z/VM, CPUs are always in a configured state.

  if **chcpu -g** is supported, any **disabled** CPUs should be **deconfigured** to inform the hypervisor that these CPUs won’t be used, avoiding potential performance penalties.

- **-p**, **--dispatch** *mode*

  Set the CPU dispatching *mode* (polarization). This option has an effect only if your hardware architecture and hypervisor support CPU polarization. Available *modes* are:

  **horizontal**

  The workload is spread across all available CPUs.

  **vertical**

  The workload is concentrated on few CPUs.

- **-r**, **--rescan**

  Trigger a rescan of CPUs. After a rescan, the Linux kernel recognizes the new CPUs. Use this option on systems that do not automatically detect newly attached CPUs.

- **-h**, **--help**

  Display help text and exit.

- **-V**, **--version**

  Display version and exit.

## EXIT STATUS

**chcpu** has the following exit status values:

**0**

success

**1**

failure

**64**

partial success

## AUTHORS

*Heiko Carstens* \<heiko.carstens@de.ibm.com\>

## COPYRIGHT

Copyright IBM Corp. 2011

## SEE ALSO

[**lscpu**(1)](/lscpu/1.md)

## REPORTING BUGS

For bug reports, use the *issue tracker* \<https://github.com/util-linux/util-linux/issues\>.

## AVAILABILITY

The **chcpu** command is part of the util-linux package which can be downloaded from *Linux Kernel Archive* \<https://www.kernel.org/pub/linux/utils/util-linux/\>.