NAME
trace-cmd-reset - turn off all Ftrace tracing to bring back full performanceSYNOPSIS
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_sizeWhen 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).
-B buffer-name
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.
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
trace-cmd reset -a -d
trace-cmd reset -t -a -d
trace-cmd reset -a -t -d
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, < [email protected][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
mailto:[email protected]
01/22/2023 | libtracefs |