Documentation/rtla: Include defaults for tracer options

Commit 0122938a7a ("rtla: Always set all tracer options") changed the
behavior of RTLA to always set all osnoise and timerlat tracer options
to default values taken from the tracers whenever an RTLA measurement
is started. The change was done to make RTLA results consistent on
subsequent runs of the same command.

Include the default values for tracer options also in documentation
where appropriate.

Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20251010083338.478961-10-tglozar@redhat.com>

Documentation/tools/rtla/common_options.txt

@@ -2,10 +2,14 @@
 
         Set the |tool| tracer to run the sample threads in the cpu-list.
 
+        By default, the |tool| tracer runs the sample threads on all CPUs.
+
 **-H**, **--house-keeping** *cpu-list*
 
         Run rtla control threads only on the given cpu-list.
 
+        If omitted, rtla will attempt to auto-migrate its main thread to any CPU that is not running any workload threads.
+
 **-d**, **--duration** *time[s|m|h|d]*
 
         Set the duration of the session.
@@ -57,6 +61,8 @@
 **--trace-buffer-size** *kB*
         Set the per-cpu trace buffer size in kB for the tracing output.
 
+        If not set, the default tracefs buffer size is used.
+
 **--on-threshold** *action*
 
         Defines an action to be executed when tracing is stopped on a latency threshold