trace-cmd extract [OPTIONS]
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.
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
With out this option, the extract command will extract from the internal Ftrace buffers.
- 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.
- By default, the extract command will create a trace.dat file. This option will change where the file is written to.
- Extract from the snapshot buffer (if the kernel supports it).
Written by Steven Rostedt, <m[blue][email protected]m>
Copyright (C) 2010 Red Hat, Inc. Free use of this software is granted under the terms of the GNU Public License (GPL).