8262235: Remove unnecessary logic in hugetlbfs_sanity_check()

Reviewed-by: iwalulya, tschatzl

Author: kstefanj

src/hotspot/os/linux/os_linux.cpp

@@ -3493,39 +3493,21 @@ int os::Linux::hugetlbfs_page_size_flag(size_t page_size) {
 }
 
 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) {
-  bool result = false;
-
   // Include the page size flag to ensure we sanity check the correct page size.
   int flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_HUGETLB | hugetlbfs_page_size_flag(page_size);
   void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE, flags, -1, 0);
 
   if (p != MAP_FAILED) {
-    // We don't know if this really is a huge page or not.
-    FILE *fp = fopen("/proc/self/maps", "r");
-    if (fp) {
-      while (!feof(fp)) {
-        char chars[257];
-        long x = 0;
-        if (fgets(chars, sizeof(chars), fp)) {
-          if (sscanf(chars, "%lx-%*x", &x) == 1
-              && x == (long)p) {
-            if (strstr (chars, "hugepage")) {
-              result = true;
-              break;
-            }
-          }
-        }
-      }
-      fclose(fp);
-    }
+    // Mapping succeeded, sanity check passed.
     munmap(p, page_size);
+    return true;
   }
 
-  if (warn && !result) {
-    warning("HugeTLBFS is not supported by the operating system.");
+  if (warn) {
+    warning("HugeTLBFS is not configured or not supported by the operating system.");
   }
 
-  return result;
+  return false;
 }
 
 bool os::Linux::shm_hugetlbfs_sanity_check(bool warn, size_t page_size) {