---
name: "oomkill.bt.bt"
section: "8"
platform: "linux"
package: "bpftrace"
version: "0.17.0-1"
release: "Debian 12 (Bookworm)"
platforms: ["linux"]
url: "https://new.carta.tech/oomkill.bt.bt"
---

# oomkill.bt.bt(8)

Trace OOM killer. Uses bpftrace/eBPF.

## NAME

oomkill.bt - Trace OOM killer. Uses bpftrace/eBPF.

## SYNOPSIS

**oomkill.bt**

## DESCRIPTION

This traces the kernel out-of-memory killer, and prints basic details, including the system load averages at the time of the OOM kill. This can provide more context on the system state at the time: was it getting busier or steady, based on the load averages? This tool may also be useful to customize for investigations; for example, by adding other task\_struct details at the time of OOM, or by adding other commands to run at the shell.

Since this uses BPF, only the root user can use this tool.

## REQUIREMENTS

CONFIG\_BPF and bpftrace.

## EXAMPLES

- Trace OOM kill events:

  \# **oomkill.bt**

## FIELDS

- Triggered by ...

  The process ID and process name of the task that was running when another task was OOM killed.

- OOM kill of ...

  The process ID and name of the target process that was OOM killed.

- loadavg

  Contents of /proc/loadavg. The first three numbers are 1, 5, and 15 minute load averages (where the average is an exponentially damped moving sum, and those numbers are constants in the equation); then there is the number of running tasks, a slash, and the total number of tasks; and then the last number is the last PID to be created.

## OVERHEAD

Negligible.

## SOURCE

This is from bpftrace.

-

  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.

This is a bpftrace version of the bcc tool of the same name. The bcc tool may provide more options and customizations.

-

  https://github.com/iovisor/bcc

## OS

Linux

## STABILITY

Unstable - in development.

## AUTHOR

Brendan Gregg

## SEE ALSO

[dmesg(1)](/dmesg/1.md)