1TRACE-CMD-SHOW(1)                                            TRACE-CMD-SHOW(1)
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NAME

6       trace-cmd-show - show the contents of the Ftrace Linux kernel tracing
7       buffer.
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SYNOPSIS

10       trace-cmd show [OPTIONS]
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DESCRIPTION

13       The trace-cmd(1) show displays the contents of one of the Ftrace Linux
14       kernel tracing files: trace, snapshot, or trace_pipe. It is basically
15       the equivalent of doing:
16
17           cat /sys/kernel/debug/tracing/trace
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OPTIONS

20       -p
21           Instead of displaying the contents of the "trace" file, use the
22           "trace_pipe" file. The difference between the two is that the
23           "trace" file is static. That is, if tracing is stopped, the "trace"
24           file will show the same contents each time.
25
26               The "trace_pipe" file is a consuming read, where a read of the file
27               will consume the output of what was read and it will not read the
28               same thing a second time even if tracing is stopped. This file
29               als will block. If no data is available, trace-cmd show will stop
30               and wait for data to appear.
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32       -s
33           Instead of reading the "trace" file, read the snapshot file. The
34           snapshot is made by an application writing into it and the kernel
35           will perform as swap between the currently active buffer and the
36           current snapshot buffer. If no more swaps are made, the snapshot
37           will remain static. This is not a consuming read.
38
39       -c cpu
40           Read only the trace file for a specified CPU.
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42       -f
43           Display the full path name of the file that is being displayed.
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45       -B buf
46           If a buffer instance was created, then the -B option will access
47           the files associated with the given buffer.
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49       --tracing_on
50           Show if tracing is on for the given instance.
51
52       --current_tracer
53           Show what the current tracer is.
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55       --buffer_size
56           Show the current buffer size (per-cpu)
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58       --buffer_total_size
59           Show the total size of all buffers.
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61       --ftrace_filter
62           Show what function filters are set.
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64       --ftrace_notrace
65           Show what function disabled filters are set.
66
67       --ftrace_pid
68           Show the PIDs the function tracer is limited to (if any).
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70       --graph_function
71           Show the functions that will be graphed.
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73       --graph_notrace
74           Show the functions that will not be graphed.
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76       --cpumask
77           Show the mask of CPUs that tracing will trace.
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SEE ALSO

80       trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1),
81       trace-cmd-start(1), trace-cmd-extract(1), trace-cmd-reset(1),
82       trace-cmd-split(1), trace-cmd-list(1), trace-cmd-listen(1)
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AUTHOR

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

88       git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git
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COPYING

91       Copyright (C) 2010 Red Hat, Inc. Free use of this software is granted
92       under the terms of the GNU Public License (GPL).
93

NOTES

95        1. rostedt@goodmis.org
96           mailto:rostedt@goodmis.org
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100                                  12/02/2020                 TRACE-CMD-SHOW(1)
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