In cgroup v2, memory and hugetlb usage reparenting is asynchronous. This can cause test flakiness when immediately asserting usage after deleting a child cgroup. To address this, add a helper function `assert_with_retry()` that checks usage values with a timeout-based retry. This improves test stability without relying on fixed sleep delays.
Also bump up the tolerance size to 7MB.
To avoid False Positives: ... # Assert memory charged correctly for child only use. # actual a = 11 MB # expected a = 0 MB # fail # cleanup # [FAIL] not ok 11 hugetlb_reparenting_test.sh -cgroup-v2 # exit=1 # 0 # SUMMARY: PASS=10 SKIP=0 FAIL=1
Signed-off-by: Li Wang liwang@redhat.com Cc: Waiman Long longman@redhat.com Cc: Anshuman Khandual anshuman.khandual@arm.com Cc: Dev Jain dev.jain@arm.com Cc: Kirill A. Shuemov kirill.shutemov@linux.intel.com Cc: Shuah Khan shuah@kernel.org --- .../selftests/mm/hugetlb_reparenting_test.sh | 96 ++++++++----------- 1 file changed, 41 insertions(+), 55 deletions(-)
diff --git a/tools/testing/selftests/mm/hugetlb_reparenting_test.sh b/tools/testing/selftests/mm/hugetlb_reparenting_test.sh index 11f9bbe7dc22..1c172c6999f4 100755 --- a/tools/testing/selftests/mm/hugetlb_reparenting_test.sh +++ b/tools/testing/selftests/mm/hugetlb_reparenting_test.sh @@ -36,7 +36,7 @@ else do_umount=1 fi fi -MNT='/mnt/huge/' +MNT='/mnt/huge'
function get_machine_hugepage_size() { hpz=$(grep -i hugepagesize /proc/meminfo) @@ -60,6 +60,41 @@ function cleanup() { set -e }
+function assert_with_retry() { + local actual_path="$1" + local expected="$2" + local tolerance=$((7 * 1024 * 1024)) + local timeout=20 + local interval=1 + local start_time + local now + local elapsed + local actual + + start_time=$(date +%s) + + while true; do + actual="$(cat "$actual_path")" + + if [[ $actual -ge $(($expected - $tolerance)) ]] && + [[ $actual -le $(($expected + $tolerance)) ]]; then + return 0 + fi + + now=$(date +%s) + elapsed=$((now - start_time)) + + if [[ $elapsed -ge $timeout ]]; then + echo "actual = $((${actual%% *} / 1024 / 1024)) MB" + echo "expected = $((${expected%% *} / 1024 / 1024)) MB" + cleanup + exit 1 + fi + + sleep $interval + done +} + function assert_state() { local expected_a="$1" local expected_a_hugetlb="$2" @@ -70,58 +105,13 @@ function assert_state() { expected_b="$3" expected_b_hugetlb="$4" fi - local tolerance=$((5 * 1024 * 1024)) - - local actual_a - actual_a="$(cat "$CGROUP_ROOT"/a/memory.$usage_file)" - if [[ $actual_a -lt $(($expected_a - $tolerance)) ]] || - [[ $actual_a -gt $(($expected_a + $tolerance)) ]]; then - echo actual a = $((${actual_a%% *} / 1024 / 1024)) MB - echo expected a = $((${expected_a%% *} / 1024 / 1024)) MB - echo fail - - cleanup - exit 1 - fi - - local actual_a_hugetlb - actual_a_hugetlb="$(cat "$CGROUP_ROOT"/a/hugetlb.${MB}MB.$usage_file)" - if [[ $actual_a_hugetlb -lt $(($expected_a_hugetlb - $tolerance)) ]] || - [[ $actual_a_hugetlb -gt $(($expected_a_hugetlb + $tolerance)) ]]; then - echo actual a hugetlb = $((${actual_a_hugetlb%% *} / 1024 / 1024)) MB - echo expected a hugetlb = $((${expected_a_hugetlb%% *} / 1024 / 1024)) MB - echo fail - - cleanup - exit 1 - fi - - if [[ -z "$expected_b" || -z "$expected_b_hugetlb" ]]; then - return - fi - - local actual_b - actual_b="$(cat "$CGROUP_ROOT"/a/b/memory.$usage_file)" - if [[ $actual_b -lt $(($expected_b - $tolerance)) ]] || - [[ $actual_b -gt $(($expected_b + $tolerance)) ]]; then - echo actual b = $((${actual_b%% *} / 1024 / 1024)) MB - echo expected b = $((${expected_b%% *} / 1024 / 1024)) MB - echo fail - - cleanup - exit 1 - fi
- local actual_b_hugetlb - actual_b_hugetlb="$(cat "$CGROUP_ROOT"/a/b/hugetlb.${MB}MB.$usage_file)" - if [[ $actual_b_hugetlb -lt $(($expected_b_hugetlb - $tolerance)) ]] || - [[ $actual_b_hugetlb -gt $(($expected_b_hugetlb + $tolerance)) ]]; then - echo actual b hugetlb = $((${actual_b_hugetlb%% *} / 1024 / 1024)) MB - echo expected b hugetlb = $((${expected_b_hugetlb%% *} / 1024 / 1024)) MB - echo fail + assert_with_retry "$CGROUP_ROOT/a/memory.$usage_file" "$expected_a" + assert_with_retry "$CGROUP_ROOT/a/hugetlb.${MB}MB.$usage_file" "$expected_a_hugetlb"
- cleanup - exit 1 + if [[ -n "$expected_b" && -n "$expected_b_hugetlb" ]]; then + assert_with_retry "$CGROUP_ROOT/a/b/memory.$usage_file" "$expected_b" + assert_with_retry "$CGROUP_ROOT/a/b/hugetlb.${MB}MB.$usage_file" "$expected_b_hugetlb" fi }
@@ -174,7 +164,6 @@ size=$((${MB} * 1024 * 1024 * 25)) # 50MB = 25 * 2MB hugepages.
cleanup
-echo echo echo Test charge, rmdir, uncharge setup @@ -195,7 +184,6 @@ cleanup
echo done echo -echo if [[ ! $cgroup2 ]]; then echo "Test parent and child hugetlb usage" setup @@ -212,7 +200,6 @@ if [[ ! $cgroup2 ]]; then assert_state 0 $(($size * 2)) 0 $size
rmdir "$CGROUP_ROOT"/a/b - sleep 5 echo Assert memory reparent correctly. assert_state 0 $(($size * 2))
@@ -224,7 +211,6 @@ if [[ ! $cgroup2 ]]; then cleanup fi
-echo echo echo "Test child only hugetlb usage" echo setup