naptime.bt(8)

📦
version 0.27.0 · 3 versions
  • 0.27.0 · alpine 3.24, arch rolling, centos-stream 10, centos-stream 9, debian trixie, fedora 43, fedora 44, nixos 26.05, nixpkgs unstable, opensuse-leap 16.0, ubuntu questing, ubuntu resolute, ubuntu stonking (latest)
  • 0.14.0 · ubuntu jammy
  • 0.20.2 · ubuntu noble
, in alpine 3.24, arch rolling, centos-stream 10, centos-stream 9, debian trixie, fedora 43, fedora 44, nixos 26.05, nixpkgs unstable, opensuse-leap 16.0, ubuntu questing, ubuntu resolute, ubuntu stonking

💖 naptime.bt(8) 💖

System Manager's Manual 🌸 manual name: naptime.bt

✨ NAME ✨

okay so naptime.bt is the tool that traces voluntary sleep calls 😴 It runs on bpftrace/eBPF and it is literally iconic for this. 💅

🎀 SYNOPSIS 🎀

naptime.bt

🦋 DESCRIPTION 🦋

okay bestie, this tool traces application sleeps 💤 So if your app is being slow and you have no idea why, it could be because someone put deliberate sleeps in the routines, especially in admin scripts. 🙈 naptime.bt helps you find those nap times and debug the high latency. It's giving detective energy, fr fr. 🔍

Here's how it works: it traces the nanosleep(2) syscall using the syscall tracepoints. ⭐

🚨 Since this uses BPF, only the root user can use this tool. No cap, you need to be root to get in here. 👑

🧚 REQUIREMENTS 🧚

You need CONFIG_BPF and bpftrace. ✨

💅 EXAMPLES 💅

Trace application sleeps via nanosleep(2):

# naptime.bt

🌈 FIELDS 🌈

  • TIME — a timestamp in HH:MM:SS format. ⏰
  • PPID — the parent process ID. 👪
  • PCOMM — the parent process name. 🫶
  • PID — the ID of the process that's sleeping. 😴
  • COMM — the name of the process that's sleeping. 🍓
  • SECONDS — how long the sleep was requested to last. ⏳

🌸 OVERHEAD 🌸

Okay this is the best part: nanosleep(2) calls are expected to be low frequency (<< 100/s), so the overhead of this tool is expected to be negligible. 💜 Basically it won't slow your day down. 🥹

📚 SOURCE 📚

This tool originated from the book "BPF Performance Tools", published by Addison Wesley (2019):

http://www.brendangregg.com/bpf-performance-tools-book.html

See the book for more documentation on this tool. 📖

This version lives in the bpftrace repository:

https://github.com/bpftrace/bpftrace

Also look in the bpftrace distribution for a companion _examples.txt file. It has example usage, output, and commentary for this tool, so it's a must-read. 🫶

🖥️ OS 🖥️

Linux 🐧

🧪 STABILITY 🧪

Unstable - in development. 🚧 Use it, love it, but know it's still cooking. 🍳

👑 AUTHOR 👑

Brendan Gregg 🙌

🔗 SEE ALSO 🔗

capable.bt(8) 🦋

Signed with love by your favourite Unix nerd 💖 USER COMMANDS manual, dated 2019-07-05, covering naptime.bt(8) ✨ bye bestie 🫶🌈

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