[merged mm-stable] selftests-damon-sysfspy-pause-damon-before-dumping-status.patch removed from -mm tree

[merged mm-stable] selftests-damon-sysfspy-pause-damon-before-dumping-status.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: selftests/damon/sysfs.py: pause DAMON before dumping status
has been removed from the -mm tree.  Its filename was
     selftests-damon-sysfspy-pause-damon-before-dumping-status.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: SeongJae Park <sj@kernel.org>
Subject: selftests/damon/sysfs.py: pause DAMON before dumping status
Date: Mon, 27 Apr 2026 08:12:29 -0700

The sysfs.py test commits DAMON parameters, dump the internal DAMON state,
and show if the parameters are committed as expected using the dumped
state.  While the dumping is ongoing, DAMON is alive.  It can make
internal changes including addition and removal of regions.  It can
therefore make a race that can result in false test results.  Pause DAMON
execution during the state dumping to avoid such races.

Link: https://lore.kernel.org/20260427151231.113429-11-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
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@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/damon/sysfs.py |   38 +++++++++++++++++++++++
 1 file changed, 38 insertions(+)

--- a/tools/testing/selftests/damon/sysfs.py~selftests-damon-sysfspy-pause-damon-before-dumping-status
+++ a/tools/testing/selftests/damon/sysfs.py
@@ -198,18 +198,55 @@ def assert_ctx_committed(ctx, dump):
     assert_true(dump['pause'] == ctx.pause, 'pause', dump)
 
 def assert_ctxs_committed(kdamonds):
+    ctxs_paused_for_dump = []
+    kdamonds_paused_for_dump = []
+    # pause for safe state dumping
+    for kd in kdamonds.kdamonds:
+        for ctx in kd.contexts:
+            if ctx.pause is False:
+                ctx.pause = True
+                ctxs_paused_for_dump.append(ctx)
+                if not kd in kdamonds_paused_for_dump:
+                    kdamonds_paused_for_dump.append(kd)
+        if kd in kdamonds_paused_for_dump:
+            err = kd.commit()
+            if err is not None:
+                print('pause fail (%s)' % err)
+                kdamonds.stop()
+                exit(1)
+
     status, err = dump_damon_status_dict(kdamonds.kdamonds[0].pid)
     if err is not None:
         print(err)
         kdamonds.stop()
         exit(1)
 
+    # resume contexts paused for safe state dumping
+    for ctx in ctxs_paused_for_dump:
+        ctx.pause = False
+    for kd in kdamonds_paused_for_dump:
+        err = kd.commit()
+        if err is not None:
+            print('resume fail (%s)' % err)
+            kdamonds.stop()
+            exit(1)
+
+    # restore for comparison
+    for ctx in ctxs_paused_for_dump:
+        ctx.pause = True
+
     ctxs = kdamonds.kdamonds[0].contexts
     dump = status['contexts']
     assert_true(len(ctxs) == len(dump), 'ctxs length', dump)
     for idx, ctx in enumerate(ctxs):
         assert_ctx_committed(ctx, dump[idx])
 
+    # restore for the caller
+    for kd in kdamonds.kdamonds:
+        for ctx in kd.contexts:
+            if ctx in ctxs_paused_for_dump:
+                ctx.pause = False
+
 def main():
     kdamonds = _damon_sysfs.Kdamonds(
             [_damon_sysfs.Kdamond(
@@ -309,6 +346,7 @@ def main():
         print('kdamond start failed: %s' % err)
         exit(1)
     kdamonds.kdamonds[0].contexts[0].targets[1].obsolete = True
+    kdamonds.kdamonds[0].contexts[0].pause = True
     kdamonds.kdamonds[0].commit()
     del kdamonds.kdamonds[0].contexts[0].targets[1]
     assert_ctxs_committed(kdamonds)
_

Patches currently in -mm which might be from sj@kernel.org are

mm-damon-ops-common-call-folio_test_lru-after-folio_get.patch
mm-damon-reclaim-handle-ctx-allocation-failure.patch
mm-damonn-lru_sort-handle-ctx-allocation-failure.patch
mm-damon-core-introduce-struct-damon_probe.patch
mm-damon-core-embed-damon_probe-objects-in-damon_ctx.patch
mm-damon-core-introduce-damon_filter.patch
mm-damon-core-commit-probes.patch
mm-damon-core-introduce-damon_region-probe_hits.patch
mm-damon-core-introduce-damon_ops-apply_probes.patch
mm-damon-core-do-data-attributes-monitoring.patch
mm-damon-paddr-support-data-attributes-monitoring.patch
mm-damon-sysfs-implement-probes-dir.patch
mm-damon-sysfs-implement-probe-dir.patch
mm-damon-sysfs-implement-filters-directory.patch
mm-damon-sysfs-implement-filter-dir.patch
mm-damon-sysfs-implement-filter-dir-files.patch
mm-damon-sysfs-setup-probes-on-damon-core-api-parameters.patch
mm-damon-sysfs-schemes-implement-tried_regions-r-probes.patch
mm-damon-sysfs-schemes-implement-probe-dir.patch
mm-damon-sysfs-schemes-implement-probe-hits-file.patch
mm-damon-trace-probe_hits.patch
selftests-damon-sysfssh-test-probes-dir.patch
docs-mm-damon-design-document-data-attributes-monitoring.patch
docs-admin-guide-mm-damon-usage-document-data-attributes-monitoring.patch
mm-damon-core-introduce-damon_filter_type_memcg.patch
mm-damon-paddr-support-damon_filter_type_memcg.patch
mm-damon-sysfs-add-filters-f-path-file.patch
mm-damon-sysfs-schemes-move-memcg_path_to_id-to-sysfs-common.patch
mm-damon-sysfs-setup-damon_filter-memcg_id-from-path.patch
docs-mm-damon-design-update-for-memcg-damon-filter.patch
docs-admin-guide-mm-damon-usage-update-for-memcg-damon-filter.patch
mm-damon-core-safely-handle-no-region-case-in-damon_set_regions.patch
mm-damon-core-do-not-use-region-out-of-a-loop-in-damon_set_regions.patch
samples-damon-mtier-replace-damon_add_region-with-damon_set_regions.patch
mm-damon-tests-vaddr-kunit-replace-damon_add_region-with-damon_set_regions.patch
mm-damon-core-hide-damon_add_region.patch
mm-damon-core-hide-damon_insert_region.patch
mm-damon-core-hide-damon_destroy_region.patch
mm-damon-core-add-kdamond_call-debug_sanity-check.patch
mm-damon-core-remove-damon_verify_nr_regions.patch
mm-damon-tests-core-kunit-add-damon_set_regions-test-cases.patch
selftests-damon-sysfspy-stop-kdamonds-before-failing.patch
selftests-damon-sysfssh-test-monitoring-intervals-goal-dir.patch
selftests-damon-sysfssh-test-addr_unit-file-existence.patch
selftests-damon-sysfssh-test-pause-file-existence.patch
mm-damon-core-trace-esz-at-first-setup.patch