[PATCH v6 12/21] selftests/resctrl: Check for resctrl mount point only if resctrl FS is supported

From: Fenghua Yu
Date: Tue Mar 16 2021 - 22:27:34 EST

check_resctrlfs_support() does the following
1. Checks if the platform supports resctrl file system or not by looking
for resctrl in /proc/filesystems
2. Calls opendir() on default resctrl file system path
(i.e. /sys/fs/resctrl)
3. Checks if resctrl file system is mounted or not by looking at

Steps 2 and 3 will fail if the platform does not support resctrl file
system. So, there is no need to check for them if step 1 fails.

Fix this by returning immediately if the platform does not support
resctrl file system.

Tested-by: Babu Moger <babu.moger@xxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
tools/testing/selftests/resctrl/resctrlfs.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 6b22a186790a..87195eb78356 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -570,6 +570,9 @@ bool check_resctrlfs_support(void)
ksft_print_msg("%s kernel supports resctrl filesystem\n",
ret ? "Pass:" : "Fail:");

+ if (!ret)
+ return ret;
dp = opendir(RESCTRL_PATH);
ksft_print_msg("%s resctrl mountpoint \"%s\" exists\n",
dp ? "Pass:" : "Fail:", RESCTRL_PATH);