naptime.bt(8)

NAME
naptime.bt - Trace voluntary sleep calls. Uses bpftrace/eBPF.

SYNOPSIS
naptime.bt

DESCRIPTION
This tool traces application sleeps, and can be used for debugging high latency that may be caused by deliberate sleeps placed in application routines, especially administration scripts. This tool works by tracing the nanosleep(2) syscall using the syscall tracepoints. Since this uses BPF, only the root user can use this tool.

REQUIREMENTS
CONFIG_BPF and bpftrace.

EXAMPLES

Trace application sleeps via nanosleep(2):
    # naptime.bt

FIELDS

TIME
    A timestamp in HH:MM:SS format.

PPID
    Parent process ID.

PCOMM
    Parent process name.

PID The sleeping process ID.

COMM
    The sleeping process name.

SECONDS
    The requested duration of the sleep.

OVERHEAD
nanosleep(2) calls are expected to be low frequency (<< 100/s), so the overhead of this tool is expected to be negligible.

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

STABILITY
Unstable - in development.

AUTHOR
Brendan Gregg

SEE ALSO
capable.bt(8)