rtla: Add rtla osnoise top documentation

Man page for rtla osnoise top mode.

Link: https://lkml.kernel.org/r/445aa2173ca152fc2e68719e3c1a2547dd01efd3.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Author: Daniel Bristot de Oliveira

Documentation/tools/rtla/common_options.rst

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+**-c**, **--cpus** *cpu-list*
+
+        Set the osnoise tracer to run the sample threads in the cpu-list.
+
+**-d**, **--duration** *time[s|m|h|d]*
+
+        Set the duration of the session.
+
+**-D**, **--debug**
+
+        Print debug info.
+
+**-t**, **--trace**\[*=file*]
+
+        Save the stopped trace to [*file|osnoise_trace.txt*].
+
+**-P**, **--priority** *o:prio|r:prio|f:prio|d:runtime:period*
+
+        Set scheduling parameters to the osnoise tracer threads, the format to set the priority are:
+
+        - *o:prio* - use SCHED_OTHER with *prio*;
+        - *r:prio* - use SCHED_RR with *prio*;
+        - *f:prio* - use SCHED_FIFO with *prio*;
+        - *d:runtime[us|ms|s]:period[us|ms|s]* - use SCHED_DEADLINE with *runtime* and *period* in nanoseconds.
+
+**-h**, **--help**
+
+        Print help menu.

Documentation/tools/rtla/common_osnoise_options.rst

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+**-p**, **--period** *us*
+
+        Set the *osnoise* tracer period in microseconds.
+
+**-r**, **--runtime** *us*
+
+        Set the *osnoise* tracer runtime in microseconds.
+
+**-s**, **--stop** *us*
+
+        Stop the trace if a single sample is higher than the argument in microseconds.
+        If **-T** is set, it will also save the trace to the output.
+
+**-S**, **--stop-total** *us*
+
+        Stop the trace if the total sample is higher than the argument in microseconds.
+        If **-T** is set, it will also save the trace to the output.

Documentation/tools/rtla/common_top_options.rst

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+**-q**, **--quiet**
+
+        Print only a summary at the end of the session.

Documentation/tools/rtla/rtla-osnoise-top.rst

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+===================
+rtla-osnoise-top
+===================
+-----------------------------------------------
+Display a summary of the operating system noise
+-----------------------------------------------
+
+:Manual section: 1
+
+SYNOPSIS
+========
+**rtla osnoise top** [*OPTIONS*]
+
+DESCRIPTION
+===========
+.. include:: common_osnoise_description.rst
+
+**rtla osnoise top** collects the periodic summary from the *osnoise* tracer,
+including the counters of the occurrence of the interference source,
+displaying the results in a user-friendly format.
+
+The tool also allows many configurations of the *osnoise* tracer and the
+collection of the tracer output.
+
+OPTIONS
+=======
+.. include:: common_osnoise_options.rst
+
+.. include:: common_top_options.rst
+
+.. include:: common_options.rst
+
+EXAMPLE
+=======
+In the example below, the **rtla osnoise top** tool is set to run with a
+real-time priority *FIFO:1*, on CPUs *0-3*, for *900ms* at each period
+(*1s* by default). The reason for reducing the runtime is to avoid starving
+the rtla tool. The tool is also set to run for *one minute* and to display
+a summary of the report at the end of the session::
+
+  [root@f34 ~]# rtla osnoise top -P F:1 -c 0-3 -r 900000 -d 1M -q
+                                          Operating System Noise
+  duration:   0 00:01:00 | time is in us
+  CPU Period       Runtime        Noise  % CPU Aval   Max Noise   Max Single          HW          NMI          IRQ      Softirq       Thread
+    0 #59         53100000       304896    99.42580        6978           56         549            0        53111         1590           13
+    1 #59         53100000       338339    99.36282        8092           24         399            0        53130         1448           31
+    2 #59         53100000       290842    99.45227        6582           39         855            0        53110         1406           12
+    3 #59         53100000       204935    99.61405        6251           33         290            0        53156         1460           12
+
+SEE ALSO
+========
+
+**rtla-osnoise**\(1), **rtla-osnoise-hist**\(1)
+
+Osnoise tracer documentation: <https://www.kernel.org/doc/html/latest/trace/osnoise-tracer.html>
+
+AUTHOR
+======
+Written by Daniel Bristot de Oliveira <bristot@kernel.org>
+
+.. include:: common_appendix.rst