NAME

syscount - Summarize syscall counts and latencies.

SYNOPSIS

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

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

-h: Print usage message.
-p PID: Trace only this process.
-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 syscalls (i.e., the return value from the syscall was < 0).
-e ERRNO: Trace only syscalls 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 syscall.
-l: 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.

EXAMPLES

Summarize all syscalls by syscall:: # syscount
Summarize all syscalls by process:: # syscount -P
Summarize only failed syscalls:: # syscount -x
Summarize only syscalls that failed with EPERM:: # syscount -e EPERM
Trace PID 181 only:: # syscount -p 181
Summarize syscalls counts and latencies:: # syscount -L

FIELDS

PID: Process ID
COMM: Process name
SYSCALL: Syscall name, or "[unknown: nnn]" for syscalls that aren't recognized
COUNT: The number of events
TIME: 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

STABILITY

Unstable - in development.

AUTHOR

Sasha Goldshtein