Man Pages

chcpu(8) - phpMan chcpu(8) - phpMan

Command: man perldoc info search(apropos)  


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 dispatch-
       ing 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
              offline, see -d, before it can be deconfigured.

       -h, --help
              Display help information and exit.

       -V, --version
              Display version information and exit.

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



Linux                              June 2012                          CHCPU(8)