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.
- -V, --version
- Display version information and exit.
- -h, --help
- Display help text and exit.
RETURN CODES¶
chcpu has the following return codes:
- 0
- success
- 1
- failure
- 64
- partial success
AUTHOR¶
Heiko
Carstens
COPYRIGHT¶
Copyright IBM Corp. 2011
SEE ALSO¶
lscpu(1)
AVAILABILITY¶
The chcpu command is part of the util-linux package and is available from
Linux
Kernel Archive