trace-cmd

Linux kernel Ftrace tracing frontend

TLDR

Display tracing status

$ sudo trace-cmd stat

List available tracers

$ sudo trace-cmd list -t

Start tracing with plugin

$ sudo trace-cmd start -p [function|function_graph|irqsoff|wakeup]

View trace output

$ sudo trace-cmd show

Stop tracing

$ sudo trace-cmd stop

Clear trace buffers

$ sudo trace-cmd clear

Record a trace of specific events

$ sudo trace-cmd record -e [sched_switch]

Record function graph tracing for a specific function

$ sudo trace-cmd record -p function_graph -g [function_name]

Display recorded trace from file

$ trace-cmd report

List available events

$ sudo trace-cmd list -e

trace-cmd is a utility for interacting with the Linux kernel's Ftrace tracing framework. It provides a user-friendly interface for configuring and capturing kernel traces, analyzing function calls, timing, and system events.The tool supports various tracer plugins including function tracing, function call graphs, and latency tracers for debugging and performance analysis.

PARAMETERS

-p PLUGIN

Specify tracer plugin (function, function_graph, irqsoff, wakeup, etc.)

-e EVENT

Enable a trace event (can be specified multiple times)

-g FUNCTION

Trace calls starting from a specific function (used with function_graph)

-o FILE

Write trace output to specified file (default: trace.dat)

-t

List available tracers (used with list subcommand)

-F

Trace only the child process after a fork

COMMANDS

stat

Display tracing system status

start

Start the kernel tracer

stop

Stop the kernel tracer

show

View current trace output

clear

Clear trace buffers

record

Record a trace to file

report

Display recorded trace

list

List available tracers, events, and functions

INSTALL

sudo apt install trace-cmd

sudo dnf install trace-cmd

sudo pacman -S trace-cmd

sudo zypper install trace-cmd

nix profile install nixpkgs#trace-cmd

CAVEATS

Requires root privileges. Tracing can impact system performance. Large traces consume significant memory and storage. Some features depend on kernel configuration.

HISTORY

trace-cmd was created by Steven Rostedt as a front-end for the Linux kernel's Ftrace framework, simplifying the process of kernel tracing and analysis.