oomkill man page

oomkill.bt ā€” 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)

Info

2018-09-07 USER COMMANDS