| TRACE-CMD-SHOW(1) |
| =================== |
| |
| NAME |
| ---- |
| trace-cmd-show - show the contents of the Ftrace Linux kernel tracing buffer. |
| |
| SYNOPSIS |
| -------- |
| *trace-cmd show* ['OPTIONS'] |
| |
| DESCRIPTION |
| ----------- |
| The trace-cmd(1) show displays the contents of one of the Ftrace Linux |
| kernel tracing files: trace, snapshot, or trace_pipe. It is basically |
| the equivalent of doing: |
| |
| cat /sys/kernel/debug/tracing/trace |
| |
| OPTIONS |
| ------- |
| *-p*:: |
| Instead of displaying the contents of the "trace" file, use the |
| "trace_pipe" file. The difference between the two is that the "trace" |
| file is static. That is, if tracing is stopped, the "trace" file |
| will show the same contents each time. |
| |
| The "trace_pipe" file is a consuming read, where a read of the file |
| will consume the output of what was read and it will not read the |
| same thing a second time even if tracing is stopped. This file |
| als will block. If no data is available, trace-cmd show will stop |
| and wait for data to appear. |
| |
| *-s*:: |
| Instead of reading the "trace" file, read the snapshot file. The snapshot |
| is made by an application writing into it and the kernel will perform |
| as swap between the currently active buffer and the current snapshot |
| buffer. If no more swaps are made, the snapshot will remain static. |
| This is not a consuming read. |
| |
| *-c* 'cpu':: |
| Read only the trace file for a specified CPU. |
| |
| *-f*:: |
| Display the full path name of the file that is being displayed. |
| |
| *-B* 'buf':: |
| If a buffer instance was created, then the *-B* option will access the |
| files associated with the given buffer. |
| |
| SEE ALSO |
| -------- |
| 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 |
| ------ |
| Written by Steven Rostedt, <rostedt@goodmis.org> |
| |
| RESOURCES |
| --------- |
| git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/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). |
| |
