naptime.bt(8)

1naptime.bt(8)               System Manager's Manual              naptime.bt(8)
2
3
4

NAME

6       naptime.bt - Trace voluntary sleep calls. Uses bpftrace/eBPF.
7

SYNOPSIS

9       naptime.bt
10

DESCRIPTION

12       This tool traces application sleeps, and can be used for debugging high
13       latency that may be caused by deliberate sleeps placed  in  application
14       routines, especially administration scripts.
15
16       This  tool  works by tracing the nanosleep(2) syscall using the syscall
17       tracepoints.
18
19       Since this uses BPF, only the root user can use this tool.
20

REQUIREMENTS

22       CONFIG_BPF and bpftrace.
23

EXAMPLES

25       Trace application sleeps via nanosleep(2):
26              # naptime.bt
27

FIELDS

29       TIME   A timestamp in HH:MM:SS format.
30
31       PPID   Parent process ID.
32
33       PCOMM  Parent process name.
34
35       PID    The sleeping process ID.
36
37       COMM   The sleeping process name.
38
39       SECONDS
40              The requested duration of the sleep.
41

OVERHEAD

43       nanosleep(2) calls are expected to be low frequency (<< 100/s), so  the
44       overhead of this tool is expected to be negligible.
45

SOURCE

47       This  tool  originated from the book "BPF Performance Tools", published
48       by Addison Wesley (2019):
49
50              http://www.brendangregg.com/bpf-performance-tools-book.html
51
52       See the book for more documentation on this tool.
53
54       This version is in the bpftrace repository:
55
56              https://github.com/iovisor/bpftrace
57
58       Also look in the bpftrace distribution for  a  companion  _examples.txt
59       file containing example usage, output, and commentary for this tool.
60

OS

62       Linux
63

STABILITY

65       Unstable - in development.
66

AUTHOR

68       Brendan Gregg
69