umount_resctrlfs() directly attempts to unmount resctrl file system without checking if resctrl FS is already mounted or not. It returns 0 on success and on failure it prints an error message and returns an error status. Calling umount_resctrlfs() when resctrl FS isn't mounted will return an error status.
There could be situations where-in the caller might not know if resctrl FS is already mounted or not and the caller might still want to unmount resctrl FS if it's already mounted (For example during teardown).
To support above use cases, change umount_resctrlfs() such that it now first checks if resctrl FS is already mounted or not and unmounts resctrl FS only if it's already mounted.
unmount resctrl FS upon exit. For example, running only mba test on a Broadwell (BDW) machine (MBA isn't supported on BDW CPU).
This happens because validate_resctrl_feature_request() would mount resctrl FS to check if mba is enabled on the platform or not and finds that the H/W doesn't support mba and hence will return false to run_mba_test(). This in turn makes the main() function return without unmounting resctrl FS.
Tested-by: Babu Moger babu.moger@amd.com Signed-off-by: Fenghua Yu fenghua.yu@intel.com --- tools/testing/selftests/resctrl/resctrl_tests.c | 2 ++ tools/testing/selftests/resctrl/resctrlfs.c | 3 +++ 2 files changed, 5 insertions(+)
diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c index fb246bc41f47..f51b5fc066a3 100644 --- a/tools/testing/selftests/resctrl/resctrl_tests.c +++ b/tools/testing/selftests/resctrl/resctrl_tests.c @@ -253,5 +253,7 @@ int main(int argc, char **argv) if (cat_test) run_cat_test(cpu_no, no_of_bits);
+ umount_resctrlfs(); + return ksft_exit_pass(); } diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c index 26563175acf6..ade5f2b8b843 100644 --- a/tools/testing/selftests/resctrl/resctrlfs.c +++ b/tools/testing/selftests/resctrl/resctrlfs.c @@ -82,6 +82,9 @@ int remount_resctrlfs(bool mum_resctrlfs)
int umount_resctrlfs(void) { + if (find_resctrl_mount(NULL)) + return 0; + if (umount(RESCTRL_PATH)) { perror("# Unable to umount resctrl");