CHCPU(8) User Manuals CHCPU(8)
NAME
chcpu - configure CPUs
SYNOPSIS
chcpu [-e] [-d] [-c] [-g] cpu-list
chcpu [-p] mode
chcpu -r
chcpu [-h] [-V]
DESCRIPTION
chcpu can modify the state of CPUs. It can enable or disable CPUs, scan for new CPUs, change the CPU dis‐
patching 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 appli‐
cable to the CPUs with the addresses 0, 5, 7, 9, 10, and 11.
OPTIONS
-r, --rescan
Trigger a rescan of CPUs. Use this option on systems that do not automatically detect newly attached
CPUs. The Linux kernel then recognizes the new CPUs.
-c, --configure cpu-list
Configure all 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.
-e, --enable cpu-list
Enable all specified CPUs. Enabling a CPU means that the kernel sets it online. A CPU must be config‐
ured, see -c, before it can be enabled.
-p, --dispatch mode
Set the CPU dispatching mode (polarization). This option has an effect only if your hardware architec‐
ture 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.
-d, --disable cpu-list
Disable all specified CPUs. Disabling a CPU means that the kernel sets it offline.
-g, --deconfigure cpu-list
Deconfigure all 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 off‐
line, see -d, before it can be deconfigured.
-h, --help
Display help information and exit.
-V, --version
Display version information and exit.
AUTHOR
Heiko Carstens ⟨[email protected]⟩
COPYRIGHT
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