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

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

NAME

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

SYNOPSIS

       trace-cmd reset [OPTIONS]

DESCRIPTION

       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

       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
               instance.

       -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).

       -a
           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.

       -d
           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.

       -t
           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

       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

       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

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

RESOURCES

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

COLOPHON

       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
       2024-06-14.  (At that time, the date of the most recent commit
       that was found in the repository was 2024-02-22.)  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 to man-pages@man7.org

libtracefs                     09/24/2023             TRACE-CMD-RESET(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-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.v6(5), trace-cmd.dat.v7(5)

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