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

The charge_reserved_hugetlb.sh script assumes hugetlb cgroup memory
interface file names use the "<size>MB" format
(e.g. hugetlb.1024MB.current).
This assumption breaks on systems with larger huge pages such as 1GB,
where the kernel exposes normalized units:
    hugetlb.1GB.current
    hugetlb.1GB.max
    hugetlb.1GB.rsvd.max
    ...

As a result, the script attempts to access files like
hugetlb.1024MB.current, which do not exist when the kernel reports the
size in GB.

Normalize the huge page size and construct the pathname using the
appropriate unit (MB or GB), matching the hugetlb controller naming.

Link: https://lore.kernel.org/04b6b49e4a2acf46319f627caf82b09e6dc1ad7f.1779296493.git.sayalip@linux.ibm.com
Fixes: 209376ed2a84 ("selftests/vm: make charge_reserved_hugetlb.sh work with existing cgroup setting")
Fixes: 29750f71a9b4 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
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>

1 files changed, 29 insertions, 13 deletions

diff --git a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
index e1945901fd20..a1cfd3a349db 100755
--- a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
+++ b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
@@ -94,6 +94,15 @@ function get_machine_hugepage_size() {
 }
 
 MB=$(get_machine_hugepage_size)
+if (( MB >= 1024 )); then
+        # For 1GB hugepages
+        UNIT="GB"
+        MB_DISPLAY=$((MB / 1024))
+else
+        # For 2MB hugepages
+        UNIT="MB"
+        MB_DISPLAY=$MB
+fi
 
 function setup_cgroup() {
   local name="$1"
@@ -103,11 +112,12 @@ function setup_cgroup() {
   mkdir $cgroup_path/$name
 
   echo writing cgroup limit: "$cgroup_limit"
-  echo "$cgroup_limit" >$cgroup_path/$name/hugetlb.${MB}MB.$fault_limit_file
+  echo "$cgroup_limit" > \
+	  $cgroup_path/$name/hugetlb.${MB_DISPLAY}${UNIT}.$fault_limit_file
 
   echo writing reservation limit: "$reservation_limit"
   echo "$reservation_limit" > \
-    $cgroup_path/$name/hugetlb.${MB}MB.$reservation_limit_file
+    $cgroup_path/$name/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_limit_file
 
   if [ -e "$cgroup_path/$name/cpuset.cpus" ]; then
     echo 0 >$cgroup_path/$name/cpuset.cpus
@@ -142,7 +152,7 @@ function wait_for_file_value() {
 
 function wait_for_hugetlb_memory_to_get_depleted() {
   local cgroup="$1"
-  local path="$cgroup_path/$cgroup/hugetlb.${MB}MB.$reservation_usage_file"
+  local path="$cgroup_path/$cgroup/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file"
 
   wait_for_file_value "$path" "0"
 }
@@ -150,7 +160,7 @@ function wait_for_hugetlb_memory_to_get_depleted() {
 function wait_for_hugetlb_memory_to_get_reserved() {
   local cgroup="$1"
   local size="$2"
-  local path="$cgroup_path/$cgroup/hugetlb.${MB}MB.$reservation_usage_file"
+  local path="$cgroup_path/$cgroup/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file"
 
   wait_for_file_value "$path" "$size"
 }
@@ -158,7 +168,7 @@ function wait_for_hugetlb_memory_to_get_reserved() {
 function wait_for_hugetlb_memory_to_get_written() {
   local cgroup="$1"
   local size="$2"
-  local path="$cgroup_path/$cgroup/hugetlb.${MB}MB.$fault_usage_file"
+  local path="$cgroup_path/$cgroup/hugetlb.${MB_DISPLAY}${UNIT}.$fault_usage_file"
 
   wait_for_file_value "$path" "$size"
 }
@@ -180,8 +190,8 @@ function write_hugetlbfs_and_get_usage() {
   hugetlb_difference=0
   reserved_difference=0
 
-  local hugetlb_usage=$cgroup_path/$cgroup/hugetlb.${MB}MB.$fault_usage_file
-  local reserved_usage=$cgroup_path/$cgroup/hugetlb.${MB}MB.$reservation_usage_file
+  local hugetlb_usage=$cgroup_path/$cgroup/hugetlb.${MB_DISPLAY}${UNIT}.$fault_usage_file
+  local reserved_usage=$cgroup_path/$cgroup/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file
 
   local hugetlb_before=$(cat $hugetlb_usage)
   local reserved_before=$(cat $reserved_usage)
@@ -312,8 +322,10 @@ function run_test() {
 
   cleanup_hugetlb_memory "hugetlb_cgroup_test"
 
-  local final_hugetlb=$(cat $cgroup_path/hugetlb_cgroup_test/hugetlb.${MB}MB.$fault_usage_file)
-  local final_reservation=$(cat $cgroup_path/hugetlb_cgroup_test/hugetlb.${MB}MB.$reservation_usage_file)
+  local final_hugetlb=$(cat \
+	 $cgroup_path/hugetlb_cgroup_test/hugetlb.${MB_DISPLAY}${UNIT}.$fault_usage_file)
+  local final_reservation=$(cat \
+	  $cgroup_path/hugetlb_cgroup_test/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file)
 
   echo $hugetlb_difference
   echo $reserved_difference
@@ -369,10 +381,14 @@ function run_multiple_cgroup_test() {
   reservation_failed1=$reservation_failed
   oom_killed1=$oom_killed
 
-  local cgroup1_hugetlb_usage=$cgroup_path/hugetlb_cgroup_test1/hugetlb.${MB}MB.$fault_usage_file
-  local cgroup1_reservation_usage=$cgroup_path/hugetlb_cgroup_test1/hugetlb.${MB}MB.$reservation_usage_file
-  local cgroup2_hugetlb_usage=$cgroup_path/hugetlb_cgroup_test2/hugetlb.${MB}MB.$fault_usage_file
-  local cgroup2_reservation_usage=$cgroup_path/hugetlb_cgroup_test2/hugetlb.${MB}MB.$reservation_usage_file
+  local cgroup1_hugetlb_usage=\
+	  $cgroup_path/hugetlb_cgroup_test1/hugetlb.${MB_DISPLAY}${UNIT}.$fault_usage_file
+  local cgroup1_reservation_usage=\
+	  $cgroup_path/hugetlb_cgroup_test1/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file
+  local cgroup2_hugetlb_usage=\
+	  $cgroup_path/hugetlb_cgroup_test2/hugetlb.${MB_DISPLAY}${UNIT}.$fault_usage_file
+  local cgroup2_reservation_usage=\
+	  $cgroup_path/hugetlb_cgroup_test2/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file
 
   local usage_before_second_write=$(cat $cgroup1_hugetlb_usage)
   local reservation_usage_before_second_write=$(cat $cgroup1_reservation_usage)