The trace-cmd(1) show displays the contents of one of the Ftrace
Linux kernel tracing files: trace, snapshot, or trace_pipe. It is
basically the equivalent of doing:
Instead of displaying the contents of the "trace" file, use
the "trace_pipe" file. The difference between the two is that
the "trace" file is static. That is, if tracing is stopped,
the "trace" file will show the same contents each time.
The "trace_pipe" file is a consuming read, where a read of the file
will consume the output of what was read and it will not read the
same thing a second time even if tracing is stopped. This file
als will block. If no data is available, trace-cmd show will stop
and wait for data to appear.
Instead of reading the "trace" file, read the snapshot file.
The snapshot is made by an application writing into it and
the kernel will perform as swap between the currently active
buffer and the current snapshot buffer. If no more swaps are
made, the snapshot will remain static. This is not a
Read only the trace file for a specified CPU.
Display the full path name of the file that is being
If a buffer instance was created, then the -B option will
access the files associated with the given buffer.
Show if tracing is on for the given instance.
Show what the current tracer is.
Show the current buffer size (per-cpu)
Show the total size of all buffers.
Show what function filters are set.
Show what function disabled filters are set.
Show the PIDs the function tracer is limited to (if any).
Show the functions that will be graphed.
Show the functions that will not be graphed.
Show the mask of CPUs that tracing will trace.
This page is part of the trace-cmd (a front-end for Ftrace)
project. Information about the project can be found at [unknown
-- if you know, please contact firstname.lastname@example.org] If you have a
bug report for this manual page, send it to Steven Rostedt
<email@example.com>. This page was obtained from the project's
upstream Git repository
on 2021-04-01. (At that time, the date of the most recent commit
that was found in the repository was 2021-03-26.) 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 firstname.lastname@example.org