[PATCH] selftests/damon/_damon_sysfs: skip testcases if CONFIG_DAMON_SYSFS is disabled

[Enze Li <lienze@kylinos.cn>]

When CONFIG_DAMON_SYSFS is disabled, the selftests fail with the
following outputs,

not ok 2 selftests: damon: sysfs_update_schemes_tried_regions_wss_estimation.py # exit=1
not ok 3 selftests: damon: damos_quota.py # exit=1
not ok 4 selftests: damon: damos_quota_goal.py # exit=1
not ok 5 selftests: damon: damos_apply_interval.py # exit=1
not ok 6 selftests: damon: damos_tried_regions.py # exit=1
not ok 7 selftests: damon: damon_nr_regions.py # exit=1
not ok 11 selftests: damon: sysfs_update_schemes_tried_regions_hang.py # exit=1

The root cause of this issue is that all the testcases above do not
check the sysfs interface of DAMON whether it exists or not.  With this
patch applied, all the testcases above now pass successfully.

Signed-off-by: Enze Li <lienze@kylinos.cn>
---
 tools/testing/selftests/damon/_damon_sysfs.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/damon/_damon_sysfs.py b/tools/testing/selftests/damon/_damon_sysfs.py
index 6e136dc3df19..cab67addfb00 100644
--- a/tools/testing/selftests/damon/_damon_sysfs.py
+++ b/tools/testing/selftests/damon/_damon_sysfs.py
@@ -15,6 +15,10 @@ if sysfs_root is None:
     print('Seems sysfs not mounted?')
     exit(ksft_skip)
 
+if not os.path.exists(sysfs_root):
+    print('Seems DAMON disabled?')
+    exit(ksft_skip)
+
 def write_file(path, string):
     "Returns error string if failed, or None otherwise"
     string = '%s' % string

base-commit: 0f70f5b08a47a3bc1a252e5f451a137cde7c98ce
-- 
2.43.0