NAME

       ppchcalls - Summarize ppc hcall counts and latencies.

SYNOPSIS

       ppchcalls [-h] [-p PID] [-t TID] [-i INTERVAL] [-d DURATION] [-T TOP] [-x] [-e ERRNO] [-L]
       [-m] [-P] [-l] [--hcall HCALL]

DESCRIPTION

       This tool traces hcall entry and exit raw tracepoints and summarizes either the number  of
       hcalls of each type, or the number of hcalls per process. It can also collect min, max and
       average latency for each hcall or each process.

       Since this uses BPF, only the root user can use this tool.

REQUIREMENTS

       CONFIG_BPF  and  bcc.  Linux  4.17+  is  required  to  attach  a  BPF   program   to   the
       raw_hcalls:hcall_{enter,exit} tracepoints, used by this tool.

OPTIONS

       -h     Print usage message.

       -p PID Trace only this process.

       -t TID Trace only this thread.

       -i INTERVAL
              Print the summary at the specified interval (in seconds).

       -d DURATION
              Total duration of trace (in seconds).

       -T TOP Print only this many entries. Default: 10.

       -x     Trace only failed hcalls (i.e., the return value from the hcall was < 0).

       -e ERRNO
              Trace only hcalls that failed with that error (e.g. -e EPERM or -e 1).

       -m     Display times in milliseconds. Default: microseconds.

       -P     Summarize by process and not by hcall.

       -l     List  the  hcalls recognized by the tool (hard-coded list). Hcalls beyond this list
              will still be displayed, as "[unknown: nnn]" where nnn is the hcall number.

       --hcall HCALL
              Trace this hcall only (use option -l to get all recognized hcalls).

EXAMPLES

       Summarize all hcalls by hcall:
              # ppchcalls

       Summarize all hcalls by process:
              # ppchcalls -P

       Summarize only failed hcalls:
              # ppchcalls -x

       Summarize only hcalls that failed with EPERM:
              # ppchcalls -e EPERM

       Trace PID 181 only:
              # ppchcalls -p 181

       Summarize hcalls counts and latencies:
              # ppchcalls -L

FIELDS

       PID    Process ID

       COMM   Process name

       HCALL  Hcall name, or "[unknown: nnn]" for hcalls that aren't recognized

       COUNT  The number of events

       MIN    The minimum elapsed time (in us or ms)

       MAX    The maximum elapsed time (in us or ms)

       AVG    The average elapsed time (in us or ms)

OVERHEAD

       For most applications, the overhead should be manageable if they perform  1000's  or  even
       10,000's of hcalls per second. For higher rates, the overhead may become considerable.

SOURCE

       This is from bcc.

              https://github.com/iovisor/bcc

       Also  look  in  the bcc distribution for a companion _examples.txt file containing example
       usage, output, and commentary for this tool.

OS

       Linux

STABILITY

       Unstable - in development.

AUTHOR

       Harsh Prateek Bora

SEE ALSO

       syscount(8)