From 7f9c0920ff3debae3cb4d60260e3daf56ab68395 Mon Sep 17 00:00:00 2001 From: Sayali Patil Date: Thu, 21 May 2026 12:17:43 +0530 Subject: [PATCH] selftests/mm: restore default nr_hugepages value via exit trap in hugetlb_reparenting_test.sh The test modifies nr_hugepages during execution and restores it from cleanup() and again reconfigure it setup, which is invoked multiple times across test flow. This can lead to repeated allocation/freeing of hugepages. With set -e, failures in cleanup (e.g., rmdir/umount) can also cause early exit before restoring the original value at the end. Move restoration of the original nr_hugepages value to a trap handler registered for EXIT, INT, and TERM signals so it is always restored on all exit paths. This also avoids unnecessary allocation churn across repeated cleanup/setup cycles. Link: https://lore.kernel.org/29db637c3c6ba6c168f6b33f59f059a0b39c35c8.1779296493.git.sayalip@linux.ibm.com Fixes: 585a9145886a ("selftests/mm: restore default nr_hugepages value during cleanup in hugetlb_reparenting_test.sh") Signed-off-by: Sayali Patil Acked-by: Zi Yan Tested-by: Venkat Rao Bagalkote Cc: David Hildenbrand (Arm) Cc: Dev Jain Cc: Liam Howlett Cc: Miaohe Lin Cc: Michal Hocko Cc: Oscar Salvador Cc: "Ritesh Harjani (IBM)" Cc: Shuah Khan Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/hugetlb_reparenting_test.sh | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/mm/hugetlb_reparenting_test.sh b/tools/testing/selftests/mm/hugetlb_reparenting_test.sh index 0dd31892ff67..11f914831146 100755 --- a/tools/testing/selftests/mm/hugetlb_reparenting_test.sh +++ b/tools/testing/selftests/mm/hugetlb_reparenting_test.sh @@ -12,6 +12,8 @@ if [[ $(id -u) -ne 0 ]]; then fi nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages) +trap 'echo "$nr_hugepgs" > /proc/sys/vm/nr_hugepages' EXIT INT TERM + usage_file=usage_in_bytes if [[ "$1" == "-cgroup-v2" ]]; then @@ -56,7 +58,6 @@ function cleanup() { rmdir "$CGROUP_ROOT"/a/b 2>/dev/null rmdir "$CGROUP_ROOT"/a 2>/dev/null rmdir "$CGROUP_ROOT"/test1 2>/dev/null - echo $nr_hugepgs >/proc/sys/vm/nr_hugepages set -e } @@ -240,4 +241,3 @@ if [[ $do_umount ]]; then rm -rf $CGROUP_ROOT fi -echo "$nr_hugepgs" > /proc/sys/vm/nr_hugepages