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.

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, <rostedt@goodmis.org[1]>

RESOURCES

       git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/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

                                            03/23/2020                       TRACE-CMD-EXTRACT(1)