1 files changed, 30 insertions, 21 deletions
diff --git a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
index fa6713892d82..447769657634 100755
--- a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
+++ b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
@@ -100,7 +100,7 @@ function setup_cgroup() {
   echo writing cgroup limit: "$cgroup_limit"
   echo "$cgroup_limit" >$cgroup_path/$name/hugetlb.${MB}MB.$fault_limit_file
 
-  echo writing reseravation limit: "$reservation_limit"
+  echo writing reservation limit: "$reservation_limit"
   echo "$reservation_limit" > \
     $cgroup_path/$name/hugetlb.${MB}MB.$reservation_limit_file
 
@@ -112,41 +112,50 @@ function setup_cgroup() {
   fi
 }
 
+function wait_for_file_value() {
+  local path="$1"
+  local expect="$2"
+  local max_tries=60
+
+  if [[ ! -r "$path" ]]; then
+    echo "ERROR: cannot read '$path', missing or permission denied"
+    return 1
+  fi
+
+  for ((i=1; i<=max_tries; i++)); do
+    local cur="$(cat "$path")"
+    if [[ "$cur" == "$expect" ]]; then
+      return 0
+    fi
+    echo "Waiting for $path to become '$expect' (current: '$cur') (try $i/$max_tries)"
+    sleep 1
+  done
+
+  echo "ERROR: timeout waiting for $path to become '$expect'"
+  return 1
+}
+
 function wait_for_hugetlb_memory_to_get_depleted() {
   local cgroup="$1"
   local path="$cgroup_path/$cgroup/hugetlb.${MB}MB.$reservation_usage_file"
-  # Wait for hugetlbfs memory to get depleted.
-  while [ $(cat $path) != 0 ]; do
-    echo Waiting for hugetlb memory to get depleted.
-    cat $path
-    sleep 0.5
-  done
+
+  wait_for_file_value "$path" "0"
 }
 
 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"
-  # Wait for hugetlbfs memory to get written.
-  while [ $(cat $path) != $size ]; do
-    echo Waiting for hugetlb memory reservation to reach size $size.
-    cat $path
-    sleep 0.5
-  done
+
+  wait_for_file_value "$path" "$size"
 }
 
 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"
-  # Wait for hugetlbfs memory to get written.
-  while [ $(cat $path) != $size ]; do
-    echo Waiting for hugetlb memory to reach size $size.
-    cat $path
-    sleep 0.5
-  done
+
+  wait_for_file_value "$path" "$size"
 }
 
 function write_hugetlbfs_and_get_usage() {