Manual: trace-cmd-extract

TRACE-CMD-EXTRACT(1)				      libtracefs Manual					TRACE-CMD-EXTRACT(1)

NAME
       trace-cmd-extract - extract out the data from the Ftrace Linux tracer.

SYNOPSIS
       trace-cmd extract [OPTIONS]

DESCRIPTION
       The trace-cmd(1) extract is usually used after trace-cmd-start(1) and trace-cmd-stop(1). It can be used after the
       Ftrace tracer has been started manually through the Ftrace pseudo file system.

       The extract command creates a trace.dat file that can be used by trace-cmd-report(1) to read from. It reads the
       kernel internal ring buffer to produce the trace.dat file.

OPTIONS
       -p plugin
	   Although extract does not start any traces, some of the plugins require just reading the output in ASCII format.
	   These are the latency tracers, since the latency tracers have a separate internal buffer. The plugin option is
	   therefore only necessary for the wakeup, wakeup-rt, irqsoff, preemptoff and preemptirqsoff plugins.

	       With out this option, the extract command will extract from the internal
	       Ftrace buffers.

       -O option
	   If a latency tracer is being extracted, and the -p option is used, then there are some Ftrace options that can
	   change the format. This will update those options before extracting. To see the list of options see
	   trace-cmd-list. To enable an option, write its name, to disable the option append the characters no to it. For
	   example: noprint-parent will disable the print-parent option that prints the parent function in printing a
	   function event.

       -o outputfile
	   By default, the extract command will create a trace.dat file. This option will change where the file is written
	   to.

       -s
	   Extract from the snapshot buffer (if the kernel supports it).

       --date
	   This is the same as the trace-cmd-record(1) --date option, but it does cause the extract routine to disable all
	   tracing. That is, the end of the extract will perform something similar to trace-cmd-reset(1).

       -B buffer-name
	   If the kernel supports multiple buffers, this will extract the trace for only the given buffer. It does not
	   affect any other buffer. This may be used multiple times to specify different buffers. When this option is used,
	   the top level instance will not be extracted unless -t is given.

       -a
	   Extract all existing buffer instances. When this option is used, the top level instance will not be extracted
	   unless -t is given.

       -t
	   Extracts the top level instance buffer. Without the -B or -a option this is the same as the default. But if -B or
	   -a is used, this is required if the top level instance buffer should also be extracted.

       --verbose[=level]
	   Set the log level. Supported log levels are "none", "critical", "error", "warning", "info", "debug", "all" or
	   their identifiers "0", "1", "2", "3", "4", "5", "6". Setting the log level to specific value enables all logs
	   from that and all previous levels. The level will default to "info" if one is not specified.

	       Example: enable all critical, error and warning logs

	       trace-cmd extract --verbose=warning

SEE ALSO
       trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1), trace-cmd-start(1), trace-cmd-stop(1), trace-cmd-reset(1),
       trace-cmd-split(1), trace-cmd-list(1), trace-cmd-listen(1)

AUTHOR
       Written by Steven Rostedt, 

RESOURCES
       https://git.kernel.org/pub/scm/utils/trace-cmd/trace-cmd.git/

COPYING
       Copyright (C) 2010 Red Hat, Inc. Free use of this software is granted under the terms of the GNU Public License
       (GPL).

NOTES
	1. rostedt@goodmis.org
	   mailto:rostedt@goodmis.org

libtracefs						 01/22/2026					TRACE-CMD-EXTRACT(1)