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.

       -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
           Print 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)

REPORTING BUGS

       For bug reports, use the issue tracker at 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/>.