[PATCH 3/5] Netperf: add option max_deviation

[Ondrej Lichtner]

From: Ondrej Lichtner <olichtne(a)redhat.com&gt;

This option limits the maximum allowed deviation. If the measured
deviation exceeds this limit the result will automatically be FAIL.
This is because sometimes the deviation gets so big that it overlaps
with the specified threshold interval resulting in a PASS even though
the result is so unstable that it shouldn't be compared to anything.

The option accepts either a percentual value describing the maximum
deviation or an absolute value in the same format that we use for
specifying the threshold.

Signed-off-by: Ondrej Lichtner <olichtne(a)redhat.com&gt;
---
 test_modules/Netperf.py | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/test_modules/Netperf.py b/test_modules/Netperf.py
index 6367808..5a9ffe7 100644
--- a/test_modules/Netperf.py
+++ b/test_modules/Netperf.py
@@ -56,6 +56,9 @@ class Netperf(TestGeneric):
         else:
             self._threshold_interval = None
 
+        self._max_deviation = self._parse_max_deviation(
+                                self.get_opt("max_deviation", default=None))
+
     def _is_omni(self):
         return self._testname in self.omni_tests
 
@@ -313,6 +316,21 @@ class Netperf(TestGeneric):
         return {"rate": threshold_rate,
                 "unit": threshold_unit_type}
 
+    def _parse_max_deviation(self, deviation):
+        if deviation is None:
+            return None
+        percentual_deviation = r"(\d+(.\d+)?)\s*%"
+        match = re.match(percentual_deviation, deviation)
+        if match:
+            return {"type": "percent",
+                    "value": float(match.group(1))}
+        else:
+            val = self._parse_threshold(deviation)
+            if val is not None:
+                return {"type": "absolute",
+                        "value": val}
+        return None
+
     def _sum_results(self, first, second):
         result = {}
 
@@ -457,6 +475,30 @@ class Netperf(TestGeneric):
         rate_dev_pretty = self._pretty_rate(rate_deviation,
unit=rate_pretty["unit"])
 
         res_val = False
+        if self._max_deviation is not None:
+            if self._max_deviation["type"] == "percent":
+                percentual_deviation = (rate_deviation / rate) * 100
+                if percentual_deviation > self._max_deviation["value"]:
+                    res_val = False
+                    res_data["msg"] = "Measured rate %.2f +-%.2f %s has
bigger "\
+                                      "deviation than allowed (+-%.2f %%)" %\
+                                      (rate_pretty["rate"],
+                                       rate_dev_pretty["rate"],
+                                       rate_pretty["unit"],
+                                       self._max_deviation["value"])
+                    return (res_val, res_data)
+            elif self._max_deviation["type"] == "absolute":
+                if rate_deviation >
self._max_deviation["value"]["rate"]:
+                    pretty_deviation =
self._pretty_rate(self._max_deviation["value"]["rate"])
+                    res_val = False
+                    res_data["msg"] = "Measured rate %.2f +-%.2f %s has
bigger "\
+                                      "deviation than allowed (+-%.2f %s)" %\
+                                      (rate_pretty["rate"],
+                                       rate_dev_pretty["rate"],
+                                       rate_pretty["unit"],
+                                       pretty_deviation["rate"],
+                                       pretty_deviation["unit"])
+                    return (res_val, res_data)
         if self._threshold_interval is not None:
             result_interval = (rate - rate_deviation,
                                rate + rate_deviation)
-- 
2.9.0