[PATCH v1] rt-tests: hwlatdetect: Add actual duration and MTBF

[Costa Shulyupin <costa.shul@xxxxxxxxxx>]

Add Mean Time Between Failures (MTBF) - a valuable statistical metric
for evaluating hardware noise and its correlation with configuration.
Add the actual duration used for the MTBF calculation.

Signed-off-by: Costa Shulyupin <costa.shul@xxxxxxxxxx>
---
 src/hwlatdetect/hwlatdetect.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/hwlatdetect/hwlatdetect.py b/src/hwlatdetect/hwlatdetect.py
index 68f312db639f..570460c9ddae 100755
--- a/src/hwlatdetect/hwlatdetect.py
+++ b/src/hwlatdetect/hwlatdetect.py
@@ -298,6 +298,7 @@     def get(self, field):
 
     def detect(self):
         self.samples = []
+        start = time.time()
         testend = time.time() + self.testduration
         pollcnt = 0
         self.start()
@@ -314,6 +315,7 @@     def detect(self):
         except KeyboardInterrupt as e:
             print("interrupted")
         self.stop()
+        self.act_duration = time.time() - start
         return self.samples
 
     def get_sample(self):
@@ -515,6 +517,7 @@ def microseconds(sval):
     detect.detect()
 
     info("test finished")
+    info(f"Duration: {detect.act_duration:.3f} seconds")
 
     max_latency = detect.get("max")
     if max_latency == 0:
@@ -527,6 +530,9 @@ def microseconds(sval):
     exceeding = detect.get("count")
     info(f"Samples exceeding threshold: {exceeding}")
 
+    if exceeding:
+        info(f"MTBF: {detect.act_duration / exceeding:.3f} seconds")
+
     if detect.have_msr:
         finishsmi = detect.getsmicounts()
         total_smis = 0
-- 
2.48.1