selftests/mm: fix hugetlb pathname construction in hugetlb_reparenting_test.sh

The hugetlb_reparenting_test.sh script constructs hugetlb cgroup memory
interface file names based on the configured huge page size.  The script
formats the size only in MB units, which causes mismatches on systems
using larger huge pages where the kernel exposes normalized units (e.g.
"1GB" instead of "1024MB").

As a result, the test fails to locate the corresponding cgroup files when
1GB huge pages are configured.

Update the script to detect the huge page size and select the appropriate
unit (MB or GB) so that the constructed paths match the kernel's hugetlb
controller naming.

Also print an explicit "Fail" message when a test failure occurs to
improve result visibility.

Link: https://lore.kernel.org/837ce751965c93f74c95d89587debf1e93281364.1779296493.git.sayalip@linux.ibm.com
Fixes: e487a5d513cb ("selftest/mm: make hugetlb_reparenting_test tolerant to async reparenting")
Signed-off-by: Sayali Patil <sayalip@linux.ibm.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/hugetlb_reparenting_test.sh b/tools/testing/selftests/mm/hugetlb_reparenting_test.sh
index 11f914831146f42bb07faf902962673724a52ab4..d724b6e45432f86f846c36b554dc9d31ae894e9a 100755 (executable)
--- a/tools/testing/selftests/mm/hugetlb_reparenting_test.sh
+++ b/tools/testing/selftests/mm/hugetlb_reparenting_test.sh
@@ -48,6 +48,13 @@ function get_machine_hugepage_size() {
 }
 
 MB=$(get_machine_hugepage_size)
+if (( MB >= 1024 )); then
+  UNIT="GB"
+  MB_DISPLAY=$((MB / 1024))
+else
+  UNIT="MB"
+  MB_DISPLAY=$MB
+fi
 
 function cleanup() {
   echo cleanup
@@ -88,6 +95,7 @@ function assert_with_retry() {
     if [[ $elapsed -ge $timeout ]]; then
       echo "actual = $((${actual%% *} / 1024 / 1024)) MB"
       echo "expected = $((${expected%% *} / 1024 / 1024)) MB"
+      echo FAIL
       cleanup
       exit 1
     fi
@@ -108,11 +116,13 @@ function assert_state() {
   fi
 
   assert_with_retry "$CGROUP_ROOT/a/memory.$usage_file" "$expected_a"
-  assert_with_retry "$CGROUP_ROOT/a/hugetlb.${MB}MB.$usage_file" "$expected_a_hugetlb"
+  assert_with_retry \
+         "$CGROUP_ROOT/a/hugetlb.${MB_DISPLAY}${UNIT}.$usage_file" "$expected_a_hugetlb"
 
   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" "$expected_b_hugetlb"
+    assert_with_retry \
+         "$CGROUP_ROOT/a/b/hugetlb.${MB_DISPLAY}${UNIT}.$usage_file" "$expected_b_hugetlb"
   fi
 }