CPUPOWER-IDLE-SET(1)

✨ NAME ✨

okay bestie, this is cpupower-idle-set 💅 It's a utility that lets you tweak the cpu idle state (aka cpu sleep state) options the kernel gives you 🦋

🎀 SYNTAX 🎀

cpupower [ -c cpulist ] idle-set [options]

💖 DESCRIPTION 💖

okay so the cpupower idle-set subcommand lets you set cpu idle options (also called sleep states) that the kernel offers 😭 One example is disabling sleep states, which is so handy when you're juggling power vs performance 🔋⚡

✨ OPTIONS ✨

• -d, --disable <STATE_NO> — disables one specific processor sleep state 💤
• -e, --enable <STATE_NO> — enables one specific processor sleep state 🌸
• -D, --disable-by-latency <LATENCY> — disables all idle states with an equal or higher latency than <LATENCY> 🙈

and the flip side: it enables all idle states with a latency lower than <LATENCY> 🫶

• -E, --enable-all — enables all idle states, if they aren't on already 🌈

🔥 REMARKS 🔥

👑 Cpuidle Governors Policy on Disabling Sleep States 👑

ngl this one is kinda the main character of the whole page 💅 Depending on which cpuidle governor is running, the kernel's policy for picking sleep states might also disable the subsequent sleep states on that core, so keep an eye out 👀

there are two cpuidle governors: ladder and menu. The ladder governor is always available as long as CONFIG_CPU_IDLE is selected, but the menu governor also needs CONFIG_NO_HZ 🧚

the disable variable acts differently depending on which governor you're using. With the ladder governor, for example, it's not coherent 😭 If you disable a light state, all the deeper states get disabled too. And if you enable a deep state while a lighter state is still disabled, nothing happens 💀

🙈 Disabling the Lightest Sleep State may not have any Affect 🙈

heads up: if the criteria for entering the deeper sleep states aren't met and the lightest sleep state gets picked when the cpu is idle, the kernel may still enter that sleep state, even if you disabled it 🥺

you can still spot this in the usage count of the disabled sleep state when you run the cpupower idle-info command 🍓

🎀 Selecting specific CPU Cores 🎀

by default, the processor sleep states of all CPU cores get set 🌍 If you only want to disable C-states on specific cores, check out the --cpu option section of the cpupower(1) manpage 🦋

📂 FILES 📂

/sys/devices/system/cpu/cpu*/cpuidle/state*
/sys/devices/system/cpu/cpuidle/*

🫶 AUTHORS 🫶

the amazing Thomas Renninger, Thomas Renninger <trenn@suse.de> 💜

🌷 SEE ALSO 🌷

cpupower(1), cpupower-monitor(1), cpupower-info(1), cpupower-set(1), cpupower-idle-info(1) 🧚

that's a wrap, bestie 🎀 This was the cpupower Manual page for CPUPOWER-IDLE-SET(1), version 0.1 💖✨ love you, mean it 🫶💅