[PATCH 2/4] selftests/damon: add tests for DAMON_RECLAIM's enabled parameter

[SeongJae Park <sj@kernel.org>]

Adds simple test cases for DAMON_RECLAIM's 'enabled' parameter.  Those
tests are focusing on the synchronous behavior of DAMON_RECLAIM enabling
and disabling.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/Makefile   |  1 +
 tools/testing/selftests/damon/reclaim.sh | 42 ++++++++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100755 tools/testing/selftests/damon/reclaim.sh

diff --git a/tools/testing/selftests/damon/Makefile b/tools/testing/selftests/damon/Makefile
index a1fa2eff8192..dbbf18cb3e6b 100644
--- a/tools/testing/selftests/damon/Makefile
+++ b/tools/testing/selftests/damon/Makefile
@@ -8,5 +8,6 @@ TEST_PROGS = debugfs_attrs.sh debugfs_schemes.sh debugfs_target_ids.sh
 TEST_PROGS += debugfs_empty_targets.sh debugfs_huge_count_read_write.sh
 TEST_PROGS += debugfs_duplicate_context_creation.sh
 TEST_PROGS += sysfs.sh
+TEST_PROGS += reclaim.sh
 
 include ../lib.mk
diff --git a/tools/testing/selftests/damon/reclaim.sh b/tools/testing/selftests/damon/reclaim.sh
new file mode 100755
index 000000000000..78dbc2334cbe
--- /dev/null
+++ b/tools/testing/selftests/damon/reclaim.sh
@@ -0,0 +1,42 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+if [ $EUID -ne 0 ]
+then
+	echo "Run as root"
+	exit $ksft_skip
+fi
+
+damon_reclaim_enabled="/sys/module/damon_reclaim/parameters/enabled"
+if [ ! -f "$damon_reclaim_enabled" ]
+then
+	echo "No 'enabled' file.  Maybe DAMON_RECLAIM not built"
+	exit $ksft_skip
+fi
+
+nr_kdamonds=$(pgrep kdamond | wc -l)
+if [ "$nr_kdamonds" -ne 0 ]
+then
+	echo "Another kdamond is running"
+	exit $ksft_skip
+fi
+
+echo Y > "$damon_reclaim_enabled"
+
+nr_kdamonds=$(pgrep kdamond | wc -l)
+if [ "$nr_kdamonds" -ne 1 ]
+then
+	echo "kdamond is not turned on"
+	exit 1
+fi
+
+echo N > "$damon_reclaim_enabled"
+nr_kdamonds=$(pgrep kdamond | wc -l)
+if [ "$nr_kdamonds" -ne 0 ]
+then
+	echo "kdamond is not turned off"
+	exit 1
+fi
-- 
2.25.1