TRACE-CMD-SNAPSHOT(1)                                  TRACE-CMD-SNAPSHOT(1)

NAME         top

       trace-cmd-snapshot - take, reset, free, or show a Ftrace kernel

SYNOPSIS         top

       trace-cmd snapshot [OPTIONS]

DESCRIPTION         top

       The trace-cmd(1) snapshot controls or displays the Ftrace Linux
       kernel snapshot feature (if the kernel supports it). This is useful
       to "freeze" an instance of a live trace but without stopping the

            trace-cmd start -p function
            trace-cmd snapshot -s
            trace-cmd snapshot
           [ dumps the content of buffer at 'trace-cmd snapshot -s' ]
            trace-cmd snapshot -s
            trace-cmd snapshot
           [ dumps the new content of the buffer at the last -s operation ]

OPTIONS         top

           Take a snapshot of the currently running buffer.

           Clear out the buffer.

           Free the snapshot buffer. The buffer takes up memory inside the
           kernel. It is best to free it when not in use. The first -s
           operation will allocate it if it is not already allocated.

       -c cpu
           Operate on a per cpu snapshot (may not be fully supported by all

       -B buf
           If a buffer instance was created, then the -B option will operate
           on the snapshot within the buffer.

SEE ALSO         top

       trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1),
       trace-cmd-start(1), trace-cmd-extract(1), trace-cmd-reset(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 2017-03-13.  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

                                 12/17/2015            TRACE-CMD-SNAPSHOT(1)