chcpu(8) - phpMan

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 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
       -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 configured, 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 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.
       -d, --disable cpu-list
              Disable all specified CPUs.  Disabling a CPU means that the ker-
              nel 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.

RETURN CODES
       chcpu has the following return codes:
       0      success
       1      failure
       64     partial success
AUTHOR
       Heiko Carstens <heiko.carstens AT de.com>
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  <ftp://ftp.kernel.org/pub/linux/utils/util-
       linux/>.

Linux                              June 2012                          CHCPU(8)