[benchmark] LogParser measure environment

Measure more of environment during test

In addition to measuring maximum resident set size, also extract number of voluntary and involuntary context switches from the verbose mode.

benchmark/scripts/test_compare_perf_tests.py

@@ -248,6 +248,22 @@ Totals,2"""
         self.assertEquals(results[1].all_samples,
                           [(0, 1, 369900), (1, 1, 381039), (2, 1, 371043)])
 
+    def test_parse_environment_verbose(self):
+        """Parse stats about environment in verbose mode."""
+        verbose_log = """    MAX_RSS 8937472 - 8904704 = 32768 (8 pages)
+    ICS 1338 - 229 = 1109
+    VCS 2 - 1 = 1
+2,AngryPhonebook,3,11269,11884,11657,338,11820
+"""
+        parser = LogParser()
+        results = parser.parse_results(verbose_log.split('\n'))
+
+        r = results[0]
+        self.assertEquals(r.max_rss, 32768)
+        self.assertEquals(r.mem_pages, 8)
+        self.assertEquals(r.voluntary_cs, 1)
+        self.assertEquals(r.involuntary_cs, 1109)
+
     def test_results_from_merge(self):
         """Parsing concatenated log merges same PerformanceTestResults"""
         concatenated_logs = """4,ArrayAppend,20,23641,29000,24990,0,24990