selftests/resctrl: Move resctrl FS mount/umount to higher level

A few places currently lack umounting resctrl FS on error paths:
  - cmt_resctrl_val() has multiple error paths with direct return.
  - cat_perf_miss_val() has multiple error paths with direct return.
In addition, validate_resctrl_feature_request() is called by
run_mbm_test() and run_mba_test(). Neither MBA nor MBM test tries to
umount resctrl FS.

Each and every test does require resctrl FS to be present already for
feature check. Thus, it makes sense to just mount it on higher level in
resctrl_tests.c and properly pair it with umount.

Move resctrl FS (re)mount/unmount into each test function in
resctrl_tests.c. Make feature validation to simply check that resctrl
FS is mounted.

As there's the final umount in main() before this change, the selftest
should not leave resctrl FS behind after the tests even if one of the
forementioned paths is taken (thus, no fixes tag).

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan (Fujitsu) <tan.shaopeng@fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

1 files changed, 41 insertions, 6 deletions

diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index 61c3882a26c8..6bf4ead74496 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -77,9 +77,15 @@ static void run_mbm_test(bool has_ben, char **benchmark_cmd, int span,
 
 	ksft_print_msg("Starting MBM BW change ...\n");
 
+	res = remount_resctrlfs(true);
+	if (res) {
+		ksft_exit_fail_msg("Failed to mount resctrl FS\n");
+		return;
+	}
+
 	if (!validate_resctrl_feature_request(MBM_STR) || (get_vendor() != ARCH_INTEL)) {
 		ksft_test_result_skip("Hardware does not support MBM or MBM is disabled\n");
-		return;
+		goto umount;
 	}
 
 	if (!has_ben)
@@ -88,6 +94,9 @@ static void run_mbm_test(bool has_ben, char **benchmark_cmd, int span,
 	ksft_test_result(!res, "MBM: bw change\n");
 	if ((get_vendor() == ARCH_INTEL) && res)
 		ksft_print_msg("Intel MBM may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
+
+umount:
+	umount_resctrlfs();
 }
 
 static void run_mba_test(bool has_ben, char **benchmark_cmd, int span,
@@ -97,15 +106,24 @@ static void run_mba_test(bool has_ben, char **benchmark_cmd, int span,
 
 	ksft_print_msg("Starting MBA Schemata change ...\n");
 
+	res = remount_resctrlfs(true);
+	if (res) {
+		ksft_exit_fail_msg("Failed to mount resctrl FS\n");
+		return;
+	}
+
 	if (!validate_resctrl_feature_request(MBA_STR) || (get_vendor() != ARCH_INTEL)) {
 		ksft_test_result_skip("Hardware does not support MBA or MBA is disabled\n");
-		return;
+		goto umount;
 	}
 
 	if (!has_ben)
 		sprintf(benchmark_cmd[1], "%d", span);
 	res = mba_schemata_change(cpu_no, bw_report, benchmark_cmd);
 	ksft_test_result(!res, "MBA: schemata change\n");
+
+umount:
+	umount_resctrlfs();
 }
 
 static void run_cmt_test(bool has_ben, char **benchmark_cmd, int cpu_no)
@@ -113,9 +131,16 @@ static void run_cmt_test(bool has_ben, char **benchmark_cmd, int cpu_no)
 	int res;
 
 	ksft_print_msg("Starting CMT test ...\n");
+
+	res = remount_resctrlfs(true);
+	if (res) {
+		ksft_exit_fail_msg("Failed to mount resctrl FS\n");
+		return;
+	}
+
 	if (!validate_resctrl_feature_request(CMT_STR)) {
 		ksft_test_result_skip("Hardware does not support CMT or CMT is disabled\n");
-		return;
+		goto umount;
 	}
 
 	if (!has_ben)
@@ -124,6 +149,9 @@ static void run_cmt_test(bool has_ben, char **benchmark_cmd, int cpu_no)
 	ksft_test_result(!res, "CMT: test\n");
 	if ((get_vendor() == ARCH_INTEL) && res)
 		ksft_print_msg("Intel CMT may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
+
+umount:
+	umount_resctrlfs();
 }
 
 static void run_cat_test(int cpu_no, int no_of_bits)
@@ -132,13 +160,22 @@ static void run_cat_test(int cpu_no, int no_of_bits)
 
 	ksft_print_msg("Starting CAT test ...\n");
 
+	res = remount_resctrlfs(true);
+	if (res) {
+		ksft_exit_fail_msg("Failed to mount resctrl FS\n");
+		return;
+	}
+
 	if (!validate_resctrl_feature_request(CAT_STR)) {
 		ksft_test_result_skip("Hardware does not support CAT or CAT is disabled\n");
-		return;
+		goto umount;
 	}
 
 	res = cat_perf_miss_val(cpu_no, no_of_bits, "L3");
 	ksft_test_result(!res, "CAT: test\n");
+
+umount:
+	umount_resctrlfs();
 }
 
 int main(int argc, char **argv)
@@ -269,7 +306,5 @@ int main(int argc, char **argv)
 	if (cat_test)
 		run_cat_test(cpu_no, no_of_bits);
 
-	umount_resctrlfs();
-
 	ksft_finished();
 }