CHCPU(8)

💅 CHCPU(8) — configure CPUs

okay bestie, listen up — this is the chcpu manual page, straight out of System Administration section 8. If you've ever wanted to boss your CPUs around like they owe you money, this is the tool. ✨

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🌸 NAME 🌸

chcpu — configure CPUs

that's it. that's the name. she configures CPUs. iconic behavior.

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✨ SYNOPSIS ✨

chcpu -c|-d|-e|-g cpu-list

chcpu -p mode

chcpu -r|-h|-V

three whole moods, pick one. The first form needs a cpu-list, the second needs a mode, and the third is just vibes (no arguments, we love a low-maintenance queen). 🫶

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🦋 DESCRIPTION 🦋

So chcpu can modify the state of CPUs. That's the whole thing. 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 (that's configure) or return CPUs to the hypervisor (that's 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. see how 9-11 expands? she contains multitudes. 🌈

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🎀 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. So like, the CPU gets adopted into the family. 💖
• -d, --disable cpu-list — Disable the specified CPUs. Disabling a CPU means that the kernel sets it offline. she's off the clock, do not perceive her. 😴
• -e, --enable cpu-list — Enable the specified CPUs. Enabling a CPU means that the kernel sets it online. IMPORTANT bestie: a CPU must be configured (see -c) before it can be enabled. no skipping steps, we do not cut corners in this house. ✋
• -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. and here's the catch: a CPU must be offline (see -d) before it can be deconfigured. also —

heads up bestie: chcpu -g is not supported on IBM z/VM — CPUs are always in a configured state there. no deconfiguring, she's committed.

and if chcpu -g is supported: any disabled CPUs should be deconfigured to inform the hypervisor that these CPUs won't be used, avoiding potential performance penalties. so like, tell the hypervisor you're not using them or she WILL hold a grudge. 😭

• -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. egalitarian queen. everyone eats. 🍽️
  • vertical — The workload is concentrated on few CPUs. focused. selective. main character energy. 👑
• -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. aka the ones that need a little nudge. 👀
• -h, --help — Display help text and exit. 🆘
• -V, --version — Display version and exit. flex your version, bestie. 💅

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💀 EXIT STATUS 💀

chcpu has the following exit status values:

• 0 — success. we ate. no crumbs. ✨
• 1 — failure. she did NOT eat. 😭
• 64 — partial success. half-ate. confusing vibe but okay. 🙈

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🌈 AUTHORS 🌈

Heiko Carstens <heiko.carstens@de.ibm.com>

shoutout to the author, real one fr fr. 🫶

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⭐ COPYRIGHT ⭐

Copyright IBM Corp. 2011

2011?? vintage. retro. classic. still slaying after all these years. 🎀

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🔥 SEE ALSO 🔥

lscpu(1)

the sibling page. the sister. go read her too, iykyk. 💜

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🐛 REPORTING BUGS 🐛

For bug reports, use the issue tracker <https://github.com/util-linux/util-linux/issues>.

found a bug? do NOT suffer in silence, go tell the tracker. that's the group chat. 📣

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🌸 AVAILABILITY 🌸

The chcpu command is part of the util-linux package which can be downloaded from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils/util-linux/>.

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and that's the whole page bestie!! 🌟

This lil masterpiece is from util-linux 2.42.4, dated 2026-09-21 — so like, she's fresh, she's current, she's serving CHCPU(8) energy. go configure some CPUs and be iconic about it. 💖✨🦋🎀