naptime.bt(8) System Manager's Manual 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)
USER COMMANDS 2019-07-05 naptime.bt(8)
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