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 <donet...@linux.ibm.com>
Signed-off-by: Li Wang <liw...@redhat.com>
Cc: Waiman Long <long...@redhat.com>
Cc: Anshuman Khandual <anshuman.khand...@arm.com>
Cc: Dev Jain <dev.j...@arm.com>
Cc: Kirill A. Shuemov <kirill.shute...@linux.intel.com>
Cc: Shuah Khan <sh...@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
