Scroll to navigation

syscount(8) System Manager's Manual syscount(8)

NAME

syscount - Summarize syscall counts and latencies.

SYNOPSIS

syscount [-h] [-p PID] [-t TID] [-i INTERVAL] [-d DURATION] [-T TOP] [-x] [-e ERRNO] [-L] [-m] [-P] [-l] [--syscall SYSCALL]

DESCRIPTION

This tool traces syscall entry and exit tracepoints and summarizes either the number of syscalls of each type, or the number of syscalls per process. It can also collect latency (invocation time) for each syscall or each process.

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

REQUIREMENTS

CONFIG_BPF and bcc. Linux 4.7+ is required to attach a BPF program to the raw_syscalls:sys_{enter,exit} tracepoints, used by this tool.

OPTIONS

Print usage message.
Trace only this process.
Trace only this thread.
Print the summary at the specified interval (in seconds).
Total duration of trace (in seconds).
Print only this many entries. Default: 10.
Trace only failed syscalls (i.e., the return value from the syscall was < 0).
Trace only syscalls that failed with that error (e.g. -e EPERM or -e 1).
Display times in milliseconds. Default: microseconds.
Summarize by process and not by syscall.
List the syscalls recognized by the tool (hard-coded list). Syscalls beyond this list will still be displayed, as "[unknown: nnn]" where nnn is the syscall number.
Trace this syscall only (use option -l to get all recognized syscalls).

EXAMPLES

# syscount
# syscount -P
# syscount -x
# syscount -e EPERM
# syscount -p 181
# syscount -L

FIELDS

Process ID
Process name
Syscall name, or "[unknown: nnn]" for syscalls that aren't recognized
The number of events
The total 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 syscalls per second. For higher rates, the overhead may become considerable. For example, tracing a loop of 4 million calls to geteuid(), slows it down by 1.85x when tracing only syscall counts, and slows it down by more than 5x when tracing syscall counts and latencies. However, this represents a rate of >3.5 million syscalls per second, which should not be typical.

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

AUTHOR

Sasha Goldshtein, Rocky Xing

SEE ALSO

funccount(8), ucalls(8), argdist(8), trace(8), funclatency(8)

2017-02-15 USER COMMANDS