naptime.bt(8)

📦 version 0.17.0, in debian bookworm

💤 naptime.bt — from the System Manager's Manual, section 8 🎀

okay bestie, picture this: it's naptime.bt and it is literally the sleep detective of your system. ✨

🌸 NAME 🌸

naptime.bt — trace voluntary sleep calls. 🛌 Uses bpftrace/eBPF, no cap.

🦋 SYNOPSIS 🦋

naptime.bt

that's it. that's the whole thing. she takes no arguments and she does not need them. 💅

✨ DESCRIPTION ✨

so this tool traces application sleeps, right? like, it's the girl who catches your code taking a lil nap when it should be working. super useful for debugging high latency that might be caused by deliberate sleeps tucked into your application routines — especially admin scripts, because we all know those scripts love a good snooze. 😴

the way it works? it traces the nanosleep(2) syscall using the syscall tracepoints. tracing the syscall, tracing the nap. iconic behavior honestly. 🔥

💀 heads up bestie: since this uses BPF, only the root user can use this tool. root only. no exceptions, no workarounds, that's the vibe.

🧚 REQUIREMENTS 🧚

  • CONFIG_BPF
  • bpftrace

both of them. together. it's giving power couple. 💖

🌈 EXAMPLES 🌈

Trace application sleeps via nanosleep(2):

# naptime.bt

that's the whole incantation. run it as root, watch the naps roll in. 🍓

👑 FIELDS 👑

okay so when the output comes through, here's what each column is serving you:

  • TIME — a timestamp in HH:MM:SS format. clock in, bestie. ⏰
  • PPID — parent process ID. the mom, essentially.
  • PCOMM — parent process name.
  • PID — the sleeping process ID. the actual napper. 😴
  • COMM — the sleeping process name.
  • SECONDS — the requested duration of the sleep. how long the nap was supposed to last. 🛌

💜 OVERHEAD 💜

nanosleep(2) calls are expected to be low frequency (<< 100/s), so the overhead of this tool is expected to be negligible. she's lightweight, she's polite, she does not eat your CPU. we love a low-maintenance icon. ✨

📚 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 is in the bpftrace repository:

https://github.com/iovisor/bpftrace

also look in the bpftrace distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool. 🎀

🐧 OS 🐧

Linux. obviously. 💅

⚠️ STABILITY ⚠️

Unstable - in development. so like, she's growing, she's evolving, she's in her development era. treat her with love and maybe don't put her in production-critical vibes without knowing that. 🦋

💖 AUTHOR 💖

Brendan Gregg 👑

🫶 SEE ALSO 🫶

and that's the whole page, bestie!! 🎉 this came out under the USER COMMANDS section of the manual, dated 2019-07-05, and it's page naptime.bt(8). go trace some sleeps, slay, and remember: naps are valid, but latency is not. 💤💖✨

📦 where this page comes from