From 67543cd6b8eee53959e624b9ce420ca4d47be0c8 Mon Sep 17 00:00:00 2001 From: Daniel Bristot de Oliveira Date: Thu, 17 Nov 2022 14:46:20 +0100 Subject: Documentation/osnoise: Add osnoise/options documentation Add the documentation about the osnoise/options file, along with an explanation about the OSNOISE_WORKLOAD option. Link: https://lkml.kernel.org/r/777af8f3d87beedd304805f98eff6c8291d64226.1668692096.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira Cc: Masami Hiramatsu Cc: Jonathan Corbet Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google) --- Documentation/trace/osnoise-tracer.rst | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'Documentation/trace') diff --git a/Documentation/trace/osnoise-tracer.rst b/Documentation/trace/osnoise-tracer.rst index 963def9f97c6..3c675ed82b27 100644 --- a/Documentation/trace/osnoise-tracer.rst +++ b/Documentation/trace/osnoise-tracer.rst @@ -109,6 +109,11 @@ The tracer has a set of options inside the osnoise directory, they are: - 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. + - 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 + NO_OSNOISE_WORKLOAD disables the OSNOISE_WORKLOAD option. The + special DEAFAULTS option resets all options to the default value. Additional Tracing ------------------ @@ -150,3 +155,10 @@ tracepoints is smaller than eight us reported in the sample_threshold. The reason roots in the overhead of the entry and exit code that happens before and after any interference execution. This justifies the dual approach: measuring thread and tracing. + +Running osnoise tracer without workload +--------------------------------------- + +By enabling the osnoise tracer with the NO_OSNOISE_WORKLOAD option set, +the osnoise: tracepoints serve to measure the execution time of +any type of Linux task, free from the interference of other tasks. -- cgit v1.2.3