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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | SEE ALSO | AUTHOR | RESOURCES | COPYING | NOTES | COLOPHON |
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TRACE-CMD-RESET(1) libtracefs Manual TRACE-CMD-RESET(1)
trace-cmd-reset - turn off all Ftrace tracing to bring back full
performance
trace-cmd reset [OPTIONS]
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.
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
immediately 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.
-k dynevent-name
This option allows preserving specified dynamic event during
reset. Valid parameters are kprobe, kretprobe, uprobe,
uretprobe, eprobe, synth and all (for keeping all dynamic
events). This may be used multiple times to specify different
dynamic event types.
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
Prevent kprobes and kretprobes from being destroyed during reset:
trace-cmd reset -k kprobe -k kretprobe
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)
Written by Steven Rostedt, <rostedt@goodmis.org[1]>
https://git.kernel.org/pub/scm/utils/trace-cmd/trace-cmd.git/
Copyright (C) 2010 Red Hat, Inc. Free use of this software is
granted under the terms of the GNU Public License (GPL).
1. rostedt@goodmis.org
mailto:rostedt@goodmis.org
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
2025-08-11. (At that time, the date of the most recent commit
that was found in the repository was 2025-08-01.) 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 01/02/2025 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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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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