Add kernel-style events for sched_trace_XXX() functions

Enable kernel-style events (tracepoint) for Litmus. Litmus events
trace the same functions as the sched_trace_XXX(), but can be
enabled independently.

So, why another tracing infrastructure then:
- Litmus tracepoints can be recorded and analyzed together (single
  time reference) with all other kernel tracing events (e.g.,
  sched:sched_switch, etc.). It's easier to correlate the effects
  of kernel events on litmus tasks.

- It enables a quick way to visualize and process schedule traces
  using trace-cmd utility and kernelshark visualizer.
  Kernelshark lacks unit-trace's schedule-correctness checks, but
  it enables a fast view of schedule traces and it has several
  filtering options (for all kernel events, not only Litmus').

1 files changed, 18 insertions, 0 deletions

diff --git a/litmus/Kconfig b/litmus/Kconfig
index 94b48e199577..68459d4dca41 100644
--- a/litmus/Kconfig
+++ b/litmus/Kconfig
@@ -138,6 +138,24 @@ config SCHED_TASK_TRACE_SHIFT
                    10 =>   1k events
                     8 =>  512 events
 
+config SCHED_LITMUS_TRACEPOINT
+        bool "Enable Event/Tracepoint Tracing for real-time task tracing"
+        depends on TRACEPOINTS
+        default n
+        help
+          Enable kernel-style events (tracepoint) for Litmus. Litmus events
+          trace the same functions as the above sched_trace_XXX(), but can
+          be enabled independently.
+          Litmus tracepoints can be recorded and analyzed together (single
+          time reference) with all other kernel tracing events (e.g.,
+          sched:sched_switch, etc.).
+
+          This also enables a quick way to visualize schedule traces using
+          trace-cmd utility and kernelshark visualizer.
+
+          Say Yes for debugging and visualization purposes.
+          Say No for overhead tracing.
+
 config SCHED_OVERHEAD_TRACE
         bool "Record timestamps for overhead measurements"
         depends on FEATHER_TRACE