trace-cmd-extract(1) — Linux manual page

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

NAME         top

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

SYNOPSIS         top

       trace-cmd extract [OPTIONS]

DESCRIPTION         top

       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         top

       -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         top

       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         top

       Written by Steven Rostedt, <rostedt@goodmis.org[1]>

RESOURCES         top

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

COPYING         top

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

NOTES         top

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

COLOPHON         top

       This page is part of the trace-cmd (a front-end for Ftrace)
       project.  Information about the project can be found at 
       ⟨https://www.trace-cmd.org/⟩.  If you have a bug report for this
       manual page, see ⟨https://www.trace-cmd.org/⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨https://git.kernel.org/pub/scm/utils/trace-cmd/trace-cmd.git⟩ on
       2025-08-11.  (At that time, the date of the most recent commit
       that was found in the repository was 2025-08-01.)  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page,
       or you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a
       mail to man-pages@man7.org

libtracefs                      09/24/2023           TRACE-CMD-EXTRACT(1)

Pages that refer to this page: trace-cmd(1),  trace-cmd-agent(1),  trace-cmd-attach(1),  trace-cmd-check-events(1),  trace-cmd-clear(1),  trace-cmd-hist(1),  trace-cmd-list(1),  trace-cmd-listen(1),  trace-cmd-mem(1),  trace-cmd-options(1),  trace-cmd-record(1),  trace-cmd-report(1),  trace-cmd-reset(1),  trace-cmd-restore(1),  trace-cmd-set(1),  trace-cmd-show(1),  trace-cmd-snapshot(1),  trace-cmd-split(1),  trace-cmd-stack(1),  trace-cmd-start(1),  trace-cmd-stat(1),  trace-cmd-stop(1),  trace-cmd.dat.v6(5),  trace-cmd.dat.v7(5)

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