[PATCH v1] perf test: Add a runs-per-test flag

[Ian Rogers <irogers@google.com>]

To detect flakes it is useful to run tests more than once. Add a
runs-per-test flag that will run each test multiple times.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/tests/builtin-test.c | 38 ++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index d2cabaa8ad92..574fbd5caff0 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -42,6 +42,8 @@
 static bool dont_fork;
 /* Fork the tests in parallel and wait for their completion. */
 static bool sequential;
+/* Numer of times each test is run. */
+static unsigned int runs_per_test = 1;
 const char *dso_to_test;
 const char *test_objdump_path = "objdump";
 
@@ -490,10 +492,10 @@ static int __cmd_test(struct test_suite **suites, int argc, const char *argv[],
 				len = strlen(test_description(*t, subi));
 				if (width < len)
 					width = len;
-				num_tests++;
+				num_tests += runs_per_test;
 			}
 		} else {
-			num_tests++;
+			num_tests += runs_per_test;
 		}
 	}
 	child_tests = calloc(num_tests, sizeof(*child_tests));
@@ -556,21 +558,25 @@ static int __cmd_test(struct test_suite **suites, int argc, const char *argv[],
 			}
 
 			if (!has_subtests(*t)) {
-				err = start_test(*t, curr, -1, &child_tests[child_test_num++],
-						 width, pass);
-				if (err)
-					goto err_out;
+				for (unsigned int run = 0; run < runs_per_test; run++) {
+					err = start_test(*t, curr, -1, &child_tests[child_test_num++],
+							width, pass);
+					if (err)
+						goto err_out;
+				}
 				continue;
 			}
-			for (int subi = 0, subn = num_subtests(*t); subi < subn; subi++) {
-				if (!perf_test__matches(test_description(*t, subi),
-							curr, argc, argv))
-					continue;
-
-				err = start_test(*t, curr, subi, &child_tests[child_test_num++],
-						 width, pass);
-				if (err)
-					goto err_out;
+			for (unsigned int run = 0; run < runs_per_test; run++) {
+				for (int subi = 0, subn = num_subtests(*t); subi < subn; subi++) {
+					if (!perf_test__matches(test_description(*t, subi),
+									curr, argc, argv))
+						continue;
+
+					err = start_test(*t, curr, subi, &child_tests[child_test_num++],
+							width, pass);
+					if (err)
+						goto err_out;
+				}
 			}
 		}
 		if (!sequential) {
@@ -714,6 +720,8 @@ int cmd_test(int argc, const char **argv)
 		    "Do not fork for testcase"),
 	OPT_BOOLEAN('S', "sequential", &sequential,
 		    "Run the tests one after another rather than in parallel"),
+	OPT_UINTEGER('r', "runs-per-test", &runs_per_test,
+		     "Run each test the given number of times, default 1"),
 	OPT_STRING('w', "workload", &workload, "work", "workload to run for testing, use '--list-workloads' to list the available ones."),
 	OPT_BOOLEAN(0, "list-workloads", &list_workloads, "List the available builtin workloads to use with -w/--workload"),
 	OPT_STRING(0, "dso", &dso_to_test, "dso", "dso to test"),
-- 
2.47.0.277.g8800431eea-goog