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


TRACE-CMD-RESET(1)                                        TRACE-CMD-RESET(1)

NAME         top

       trace-cmd-reset - turn off all Ftrace tracing to bring back full

SYNOPSIS         top

       trace-cmd reset [OPTIONS]

DESCRIPTION         top

       The trace-cmd(1) reset command turns off all tracing of Ftrace. This
       will bring back the performance of the system before tracing was
       enabled. This is necessary since trace-cmd-record(1),
       trace-cmd-stop(1) and trace-cmd-extract(1) do not disable the tracer,
       event after the data has been pulled from the buffers. The rational
       is that the user may want to manually enable the tracer with the
       Ftrace pseudo file system, or examine other parts of Ftrace to see
       what trace-cmd did. After the reset command happens, the data in the
       ring buffer, and the options that were used are all lost.

OPTIONS         top

       Please note that the order that options are specified on the command
       line is significant. See EXAMPLES.

       -b buffer_size
           When the kernel boots, the Ftrace ring buffer is of a minimal
           size (3 pages per CPU). The first time the tracer is used, the
           ring buffer size expands to what it was set for (default 1.4 Megs
           per CPU).

               If no more tracing is to be done, this option allows you to shrink the
               ring buffer down to free up available memory.

               trace-cmd reset -b 1

               The buffer instance affected is the one (or ones) specified by the most
               recently preceding *-B*, *-t*, or *-a* option:

               When used after *-B*, resizes the buffer instance that precedes it on
               the command line.

               When used after *-a*, resizes all buffer instances except the top one.

               When used after *-t* or before any *-B* or *-a*, resizes the top

       -B buffer-name
           If the kernel supports multiple buffers, this will reset the
           trace for only the given buffer. It does not affect any other
           buffer. This may be used multiple times to specify different
           buffers. The top level buffer will not be reset if this option is
           given (unless the -t option is also supplied).

           Reset the trace for all existing buffer instances. When this
           option is used, the top level instance will not be reset unless
           -t is given.

           This option deletes the instance buffer(s) specified by the most
           recently preceding -B or -a option. Because the top-level
           instance buffer cannot be deleted, it is invalid to use this
           immediatly following -t or prior to any -B or -a option on the
           command line.

           Resets 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 reset.

EXAMPLES         top

       Reset tracing for instance-one and set its per-cpu buffer size to
       4096kb. Also deletes instance-two. The top level instance and any
       other instances remain unaffected:

           trace-cmd reset -B instance-one -b 4096 -B instance-two -d

       Delete all instance buffers. Top level instance remains unaffected:

           trace-cmd reset -a -d

       Delete all instance buffers and also reset the top instance:

           trace-cmd reset -t -a -d

       Invalid. This command implies an attempt to delete the top instance:

           trace-cmd reset -a -t -d

       Reset the top instance and set its per-cpu buffer size to 1024kb. If
       any instance buffers exist, they will be unaffected:

           trace-cmd reset -b 1024

SEE ALSO         top

       trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1),
       trace-cmd-start(1), trace-cmd-stop(1), trace-cmd-extract(1),
       trace-cmd-split(1), trace-cmd-list(1), trace-cmd-listen(1)

AUTHOR         top

       Written by Steven Rostedt, <[1]>

RESOURCES         top


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


COLOPHON         top

       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] If you have a bug report for
       this manual page, send it to Steven Rostedt <>.
       This page was obtained from the project's upstream Git repository
       on 2020-09-18.  (At that time, the date of the most recent commit
       that was found in the repository was 2020-07-22.)  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

                                 05/27/2020               TRACE-CMD-RESET(1)

Pages that refer to this page: trace-cmd(1)trace-cmd-check-events(1)trace-cmd-clear(1)trace-cmd-extract(1)trace-cmd-hist(1)trace-cmd-list(1)trace-cmd-listen(1)trace-cmd-mem(1)trace-cmd-options(1)trace-cmd-profile(1)trace-cmd-record(1)trace-cmd-report(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-stream(1)trace-cmd.dat(5)