rtla/osnoise: set the default threshold to 1us

Change the default threshold for osnoise to 1us, so that any noise
equal or above this value is recorded. Let the user set a higher
threshold if necessary.

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Suggested-by: Daniel Bristot de Oliveira <[email protected]>
Reviewed-by: Clark Williams <[email protected]>
Signed-off-by: Luis Claudio R. Goncalves <[email protected]>
Acked-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

Author: lclaudio

Documentation/trace/osnoise-tracer.rst

@@ -108,7 +108,7 @@ The tracer has a set of options inside the osnoise directory, they are:
    option.
  - tracing_threshold: the minimum delta between two time() reads to be
    considered as noise, in us. When set to 0, the default value will
-   be used, which is currently 5 us.
+   be used, which is currently 1 us.
  - osnoise/options: a set of on/off options that can be enabled by
    writing the option name to the file or disabled by writing the option
    name preceded with the 'NO\_' prefix. For example, writing

kernel/trace/trace_osnoise.c

@@ -1444,9 +1444,9 @@ static int run_osnoise(void)
 	save_osn_sample_stats(osn_var, &s);
 
 	/*
-	 * if threshold is 0, use the default value of 5 us.
+	 * if threshold is 0, use the default value of 1 us.
 	 */
-	threshold = tracing_thresh ? : 5000;
+	threshold = tracing_thresh ? : 1000;
 
 	/*
 	 * Apply PREEMPT and IRQ disabled options.