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)