sys-utils/chcpu.8.adoc

   1 //po4a: entry man manual
   2 = chcpu(8)
   3 :doctype: manpage
   4 :man manual: System Administration
   5 :man source: util-linux {release-version}
   6 :page-layout: base
   7 :command: chcpu
   8
   9 == NAME
  10
  11 chcpu - configure CPUs
  12
  13 == SYNOPSIS
  14
  15 *chcpu* *-c*|*-d*|*-e*|*-g* _cpu-list_
  16
  17 *chcpu* *-p* _mode_
  18
  19 *chcpu* *-r*|*-h*|*-V*
  20
  21 == DESCRIPTION
  22
  23 *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).
  24
  25 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.
  26
  27 == OPTIONS
  28
  29 *-c*, *--configure* _cpu-list_::
  30 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.
  31
  32 *-d*, *--disable* _cpu-list_::
  33 Disable the specified CPUs. Disabling a CPU means that the kernel sets it offline.
  34
  35 *-e*, *--enable* _cpu-list_::
  36 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.
  37
  38 *-g*, *--deconfigure* _cpu-list_::
  39 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.
  40
  41 *-p*, *--dispatch* _mode_::
  42 Set the CPU dispatching _mode_ (polarization). This option has an effect only if your hardware architecture and hypervisor support CPU polarization. Available _modes_ are:
  43
  44 *horizontal*;;
  45 The workload is spread across all available CPUs.
  46
  47 *vertical*;;
  48 The workload is concentrated on few CPUs.
  49
  50 *-r*, *--rescan*::
  51 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.
  52
  53 include::man-common/help-version.adoc[]
  54
  55 == EXIT STATUS
  56
  57 *chcpu* has the following exit status values:
  58
  59 *0*::
  60 success
  61
  62 *1*::
  63 failure
  64
  65 *64*::
  66 partial success
  67
  68 == AUTHORS
  69
  70 mailto:heiko.carstens@de.ibm.com[Heiko Carstens]
  71
  72 == COPYRIGHT
  73
  74 Copyright IBM Corp. 2011
  75
  76 == SEE ALSO
  77
  78 *lscpu*(1)
  79
  80 include::man-common/bugreports.adoc[]
  81
  82 include::man-common/footer.adoc[]
  83
  84 ifdef::translation[]
  85 include::man-common/translation.adoc[]
  86 endif::[]