perf test: Print result for each BPF subtest

This patch prints each sub-tests results for BPF testcases.

Before:

  # ./perf test BPF
  37: Test BPF filter                                          : Ok

After:

  # ./perf test BPF
  37: Test BPF filter                                          :
  37.1: Test basic BPF filtering                               : Ok
  37.2: Test BPF prologue generation                           : Ok

When a failure happens:

  # cat ~/.perfconfig
  [llvm]
      clang-path = "/bin/false"
  # ./perf test BPF
  37: Test BPF filter                                          :
  37.1: Test basic BPF filtering                               : Skip
  37.2: Test BPF prologue generation                           : Skip

Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447749170-175898-5-git-send-email-wangnan0@huawei.com
[ Fixed up not to use .func in an anonymous union ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/bpf.c

@@ -215,28 +215,46 @@ out:
 	return ret;
 }
 
-int test__bpf(int subtest __maybe_unused)
+int test__bpf_subtest_get_nr(void)
+{
+	return (int)ARRAY_SIZE(bpf_testcase_table);
+}
+
+const char *test__bpf_subtest_get_desc(int i)
+{
+	if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
+		return NULL;
+	return bpf_testcase_table[i].desc;
+}
+
+int test__bpf(int i)
 {
-	unsigned int i;
 	int err;
 
+	if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
+		return TEST_FAIL;
+
 	if (geteuid() != 0) {
 		pr_debug("Only root can run BPF test\n");
 		return TEST_SKIP;
 	}
 
-	for (i = 0; i < ARRAY_SIZE(bpf_testcase_table); i++) {
-		err = __test__bpf(i);
+	err = __test__bpf(i);
+	return err;
+}
 
-		if (err != TEST_OK)
-			return err;
-	}
+#else
+int test__bpf_subtest_get_nr(void)
+{
+	return 0;
+}
 
-	return TEST_OK;
+const char *test__bpf_subtest_get_desc(int i __maybe_unused)
+{
+	return NULL;
 }
 
-#else
-int test__bpf(void)
+int test__bpf(int i __maybe_unused)
 {
 	pr_debug("Skip BPF test because BPF support is not compiled\n");
 	return TEST_SKIP;

tools/perf/tests/builtin-test.c

@@ -173,6 +173,11 @@ static struct test generic_tests[] = {
 	{
 		.desc = "Test BPF filter",
 		.func = test__bpf,
+		.subtest = {
+			.skip_if_fail	= true,
+			.get_nr		= test__bpf_subtest_get_nr,
+			.get_desc	= test__bpf_subtest_get_desc,
+		},
 	},
 	{
 		.func = NULL,

tools/perf/tests/tests.h

@@ -76,6 +76,8 @@ int test__llvm(int subtest);
 const char *test__llvm_subtest_get_desc(int subtest);
 int test__llvm_subtest_get_nr(void);
 int test__bpf(int subtest);
+const char *test__bpf_subtest_get_desc(int subtest);
+int test__bpf_subtest_get_nr(void);
 int test_session_topology(int subtest);
 
 #if defined(__arm__) || defined(__aarch64__)