Section 8 · System administration

bcc-syscount.8

Package: bcc-tools

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syscount

NAME
SYNOPSIS
DESCRIPTION
REQUIREMENTS
OPTIONS
EXAMPLES
FIELDS
OVERHEAD
SOURCE
OS
STABILITY
AUTHOR
SEE ALSO

NAME

syscount − Summarize syscall counts and latencies.

SYNOPSIS

syscount [-h] [-p PID] [-t TID] [-c PPID] [-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


	−h		Print usage message.
	−p PID		Trace only this process.
	−t TID		Trace only this thread.

−c PPID

Trace only child of this pid.

−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.

−-syscall SYSCALL

Trace this syscall only (use option -l to get all recognized syscalls).

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, Rocky Xing