CPULIMIT_FORK(1)

✨ cpulimit_fork — the manual page, bestie edition ✨

okay so this is cpulimit_fork, section 1 of the manual (User Commands, iykyk 💅). It's the little tool that goes "bestie, that process is doing the MOST" and gently tells it to chill. 🧊

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🎀 NAME 🎀

cpulimit_fork — a tool that limits the CPU usage of a specified process. fr fr, that's the whole job. 👑

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🌸 SYNOPSIS 🌸

cpulimit_fork PID PERCENT [OPTIONS]

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🦋 DESCRIPTION 🦋

cpulimit_fork is a tool for limiting the CPU usage of a specified process. The way it does this is by sending SIGSTOP and SIGCONT signals to control whether the process is running or not, making sure its CPU usage never goes over the threshold you set. no cap, it literally just pauses and unpauses your process until it behaves.

Here's the tea on how it actually works, step by step:

• It monitors the target process's CPU time (reading jiffies data from the /proc filesystem) 👀
• It keeps a circular buffer holding snapshots of the process's CPU usage
• It dynamically calculates the process's CPU usage and compares that against the limit threshold
• Based on the comparison it sends signals to control whether the process runs or gets paused
• It automatically adapts to the number of system CPU cores to adjust the limit range adaptive queen behavior

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💖 ARGUMENTS 💖

• PID — the process ID of the target process, and it must be a valid non-negative integer. The tool checks that the process actually exists, and also checks whether it has permission to control it. no sneaking into processes you don't have rights to, babe.
• PERCENT — the CPU usage limit value (a percentage). It has to be between 1 and the number of system CPU cores × 100. So for example, on a 4-core system the valid range is 1-400. math but make it cute.

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✨ OPTIONS ✨

• --lazy — turns on lazy mode (which is the default, btw). When the target process doesn't exist or has already terminated, the tool exits immediately. she said "not my problem, bye" 💅
• --no-lazy — turns lazy mode OFF. When the target process doesn't exist or has already terminated, the tool retries once every 2 seconds until the process shows up. loyal, patient, waiting by the phone energy 😭
• -h, --help — shows the help information and exits.
• -v, --version — shows the version information and exits.

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🌈 EXAMPLES 🌈

Limit the CPU usage of the process with PID 1234 to no more than 50%:

cpulimit_fork 1234 50

On a 4-core system, limit the CPU usage of the process with PID 5678 to no more than 200% (which works out to 50% of total CPU):

cpulimit_fork 5678 200

Disable lazy mode, keep waiting for and then limit the process with PID 9012, with usage no more than 30%:

cpulimit_fork 9012 30 --no-lazy

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🍓 FILES 🍓

• /proc/[PID]/stat — used to get the CPU time information of the target process 👀 the receipts
• /var/log/syslog — records the tool's run logs, including the process ID and the limit value she journals, obviously 📓

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💅 NOTES 💅

Heads up bestie, these are the important ones:

• The tool needs sufficient permissions to send signals to the target process. no permission, no signals, periodt.
• It cannot be used to limit its own process — it will show an error and exit. she does NOT do self-sabotage. 🚫
• On exit it automatically sends a SIGCONT signal to resume the target process running. she always lets you go, never leaves you frozen 🫶
• The precision of the limiting depends on the system clock and the scheduling mechanism. so like, close enough is the vibe sometimes.

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👑 SEE ALSO 👑

kill(1), top(1), proc(5), kylin-process-manager(1)

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🌸 AUTHOR 🌸

Kylin operating system development team the girlies behind the girlies 💜

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🎀 COPYRIGHT 🎀

Copyright © 2025 Kylin OS. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. free software bestie, but zero promises, ngl 🙈

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and that's the whole page, slay 💖 — this was CPULIMIT_FORK(1), brought to you by Kylin 1.0 on 2025-10-16. go forth and throttle responsibly, bestie. ✨🦋