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/Zmb-QhiiiI6jM9To@uudg.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Suggested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Reviewed-by: Clark Williams <williams@redhat.com>
Signed-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/Documentation/trace/osnoise-tracer.rst b/Documentation/trace/osnoise-tracer.rst
index 140ef2533d26a0545ba8381365844ea2d7150563..a520adbd34765bb739b7fa7b03a599c6f333cc09 100644 (file)
--- a/Documentation/trace/osnoise-tracer.rst
+++ b/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

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index a8e28f9b9271cf6545351f7d4f7ece1fbd9d8989..66a871553d4a122fdf9d09f84ea3768c08a74ad1 100644 (file)
--- a/kernel/trace/trace_osnoise.c
+++ b/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.