| Message ID | 20250407084201.74492-1-liwang@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | selftest/mm: Make hugetlb_reparenting_test tolerant to async reparenting | expand |
On 4/7/25 2:12 PM, Li Wang wrote: > 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 I was also seeing this failure. I have tested this patch on my powerPC setup and it is passing now. ./hugetlb_reparenting_test.sh -cgroup-v2 cleanup Test charge, rmdir, uncharge mkdir write Writing to this path: /mnt/huge/test Writing this size: 52428800 Populating. Not writing to memory. Using method=0 Shared mapping. RESERVE mapping. Allocating using HUGETLBFS. rmdir uncharge cleanup done Test child only hugetlb usage setup write Writing to this path: /mnt/huge/test2 Writing this size: 52428800 Populating. Not writing to memory. Using method=0 Shared mapping. RESERVE mapping. Allocating using HUGETLBFS. Assert memory charged correctly for child only use. actual = 10 MB expected = 0 MB cleanup Feel free to add Tested-by Donet Tom <donettom@linux.ibm.com> > > 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 [[ ! $cgroup2 ]]; then > cleanup > fi > > -echo > echo > echo "Test child only hugetlb usage" > echo setup
diff --git a/tools/testing/selftests/mm/hugetlb_reparenting_test.sh b/tools/testing/selftests/mm/hugetlb_reparenting_test.sh index 11f9bbe7dc22..1c172c6999f4 100755 --- a/tools/testing/selftests/mm/hugetlb_reparenting_test.sh +++ b/tools/testing/selftests/mm/hugetlb_reparenting_test.sh @@ -36,7 +36,7 @@ else do_umount=1 fi fi -MNT='/mnt/huge/' +MNT='/mnt/huge' function get_machine_hugepage_size() { hpz=$(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
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(-)