From 809ba69f9f4d17f9c04f4aaba5e680fdd71975dd Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj@kernel.org>
Date: Wed, 22 Oct 2025 18:25:33 -0700
Subject: [PATCH] selftests/damon/sysfs: add obsolete_target test

A new DAMON sysfs file for pin-point target removal, namely
obsolete_target, has been added.  Add a test for the functionality.  It
starts DAMON with three monitoring target processes, mark one in the
middle as obsolete, commit it, and confirm the internal DAMON status is
updated to remove the target in the middle.

Link: https://lkml.kernel.org/r/20251023012535.69625-10-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Bijan Tabatabai <bijan311@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 tools/testing/selftests/damon/sysfs.py | 37 ++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/tools/testing/selftests/damon/sysfs.py b/tools/testing/selftests/damon/sysfs.py
index fd8d3698326e8..b34aea0a67751 100755
--- a/tools/testing/selftests/damon/sysfs.py
+++ b/tools/testing/selftests/damon/sysfs.py
@@ -279,5 +279,42 @@ def main():
 
     kdamonds.stop()
 
+    # test obsolete_target.
+    proc1 = subprocess.Popen(['sh'], stdout=subprocess.PIPE,
+                             stderr=subprocess.PIPE)
+    proc2 = subprocess.Popen(['sh'], stdout=subprocess.PIPE,
+                             stderr=subprocess.PIPE)
+    proc3 = subprocess.Popen(['sh'], stdout=subprocess.PIPE,
+                             stderr=subprocess.PIPE)
+    kdamonds = _damon_sysfs.Kdamonds(
+            [_damon_sysfs.Kdamond(
+                contexts=[_damon_sysfs.DamonCtx(
+                    ops='vaddr',
+                    targets=[
+                        _damon_sysfs.DamonTarget(pid=proc1.pid),
+                        _damon_sysfs.DamonTarget(pid=proc2.pid),
+                        _damon_sysfs.DamonTarget(pid=proc3.pid),
+                        ],
+                    schemes=[_damon_sysfs.Damos()],
+                    )])])
+    err = kdamonds.start()
+    if err is not None:
+        print('kdamond start failed: %s' % err)
+        exit(1)
+    kdamonds.kdamonds[0].contexts[0].targets[1].obsolete = True
+    kdamonds.kdamonds[0].commit()
+
+    status, err = dump_damon_status_dict(kdamonds.kdamonds[0].pid)
+    if err is not None:
+        print(err)
+        kdamonds.stop()
+        exit(1)
+
+    del kdamonds.kdamonds[0].contexts[0].targets[1]
+
+    assert_ctxs_committed(kdamonds.kdamonds[0].contexts, status['contexts'])
+
+    kdamonds.stop()
+
 if __name__ == '__main__':
     main()
-- 
2.47.3