From 94a62284ede0250e48c886416041ad65907ee917 Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Fri, 16 Jan 2026 18:07:24 -0800 Subject: [PATCH] selftests/damon/sysfs_memcg_path_leak.sh: use kmemleak Patch series "selftests/damon: improve leak detection and wss estimation reliability". Two DAMON selftets, namely 'sysfs_memcg_leak' and 'sysfs_update_schemes_tried_regions_wss_estimation' frequently show intermittent failures due to their unreliable leak detection and working set size estimation. Make those more reliable. This patch (of 5): sysfs_memcg_path_leak.sh determines if the memory leak has happened by seeing if Slab size on /proc/meminfo increases more than expected after an action. Depending on the system and background workloads, the reasonable expectation varies. For the reason, the test frequently shows intermittent failures. Use kmemleak, which is much more reliable and correct, instead. Link: https://lkml.kernel.org/r/20260117020731.226785-1-sj@kernel.org Link: https://lkml.kernel.org/r/20260117020731.226785-2-sj@kernel.org Signed-off-by: SeongJae Park Cc: Shuah Khan Signed-off-by: Andrew Morton --- .../selftests/damon/sysfs_memcg_path_leak.sh | 26 ++++++++++--------- 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/tools/testing/selftests/damon/sysfs_memcg_path_leak.sh b/tools/testing/selftests/damon/sysfs_memcg_path_leak.sh index 64c5d8c518a42..33a7ff43ed6cc 100755 --- a/tools/testing/selftests/damon/sysfs_memcg_path_leak.sh +++ b/tools/testing/selftests/damon/sysfs_memcg_path_leak.sh @@ -14,6 +14,13 @@ then exit $ksft_skip fi +kmemleak="/sys/kernel/debug/kmemleak" +if [ ! -f "$kmemleak" ] +then + echo "$kmemleak not found" + exit $ksft_skip +fi + # ensure filter directory echo 1 > "$damon_sysfs/kdamonds/nr_kdamonds" echo 1 > "$damon_sysfs/kdamonds/0/contexts/nr_contexts" @@ -22,22 +29,17 @@ echo 1 > "$damon_sysfs/kdamonds/0/contexts/0/schemes/0/filters/nr_filters" filter_dir="$damon_sysfs/kdamonds/0/contexts/0/schemes/0/filters/0" -before_kb=$(grep Slab /proc/meminfo | awk '{print $2}') - -# try to leak 3000 KiB -for i in {1..102400}; +# try to leak 128 times +for i in {1..128}; do echo "012345678901234567890123456789" > "$filter_dir/memcg_path" done -after_kb=$(grep Slab /proc/meminfo | awk '{print $2}') -# expect up to 1500 KiB free from other tasks memory -expected_after_kb_max=$((before_kb + 1500)) - -if [ "$after_kb" -gt "$expected_after_kb_max" ] +echo scan > "$kmemleak" +kmemleak_report=$(cat "$kmemleak") +if [ "$kmemleak_report" = "" ] then - echo "maybe memcg_path are leaking: $before_kb -> $after_kb" - exit 1 -else exit 0 fi +echo "$kmemleak_report" +exit 1 -- 2.47.3