src/hotspot/os/linux/gc/z/zPhysicalMemoryBacking_linux.cpp

*** 136,153 ****
    _filesystem = buf.f_type;
    _block_size = buf.f_bsize;
    _available = buf.f_bavail * _block_size;
  
    // Make sure we're on a supported filesystem
!   if (!is_tmpfs() && !is_hugetlbfs()) {
      log_error(gc)("Backing file must be located on a %s or a %s filesystem",
                    ZFILESYSTEM_TMPFS, ZFILESYSTEM_HUGETLBFS);
      return;
    }
  
    // Make sure the filesystem type matches requested large page type
!   if (ZLargePages::is_transparent() && !is_tmpfs()) {
      log_error(gc)("-XX:+UseTransparentHugePages can only be enable when using a %s filesystem",
                    ZFILESYSTEM_TMPFS);
      return;
    }
  
--- 136,153 ----
    _filesystem = buf.f_type;
    _block_size = buf.f_bsize;
    _available = buf.f_bavail * _block_size;
  
    // Make sure we're on a supported filesystem
!   if (!ZAllowHeapOnFileSystem && !is_tmpfs() && !is_hugetlbfs()) {
      log_error(gc)("Backing file must be located on a %s or a %s filesystem",
                    ZFILESYSTEM_TMPFS, ZFILESYSTEM_HUGETLBFS);
      return;
    }
  
    // Make sure the filesystem type matches requested large page type
!   if (!ZAllowHeapOnFileSystem && ZLargePages::is_transparent() && !is_tmpfs()) {
      log_error(gc)("-XX:+UseTransparentHugePages can only be enable when using a %s filesystem",
                    ZFILESYSTEM_TMPFS);
      return;
    }
  
*** 168,178 ****
                    ZFILESYSTEM_HUGETLBFS);
      return;
    }
  
    const size_t expected_block_size = is_tmpfs() ? os::vm_page_size() : os::large_page_size();
!   if (expected_block_size != _block_size) {
      log_error(gc)("%s filesystem has unexpected block size " SIZE_FORMAT " (expected " SIZE_FORMAT ")",
                    is_tmpfs() ? ZFILESYSTEM_TMPFS : ZFILESYSTEM_HUGETLBFS, _block_size, expected_block_size);
      return;
    }
  
--- 168,178 ----
                    ZFILESYSTEM_HUGETLBFS);
      return;
    }
  
    const size_t expected_block_size = is_tmpfs() ? os::vm_page_size() : os::large_page_size();
!   if (!ZAllowHeapOnFileSystem && (expected_block_size != _block_size)) {
      log_error(gc)("%s filesystem has unexpected block size " SIZE_FORMAT " (expected " SIZE_FORMAT ")",
                    is_tmpfs() ? ZFILESYSTEM_TMPFS : ZFILESYSTEM_HUGETLBFS, _block_size, expected_block_size);
      return;
    }
  
*** 199,208 ****
--- 199,213 ----
  
    return fd;
  }
  
  int ZPhysicalMemoryBacking::create_file_fd(const char* name) const {
+   if (ZAllowHeapOnFileSystem && (AllocateHeapAt == NULL)) {
+     log_error(gc)("-XX:AllocateHeapAt is needed when ZAllowHeapOnFileSystem is specified");
+     return -1;
+   }
+ 
    const char* const filesystem = ZLargePages::is_explicit()
                                   ? ZFILESYSTEM_HUGETLBFS
                                   : ZFILESYSTEM_TMPFS;
    const char** const preferred_mountpoints = ZLargePages::is_explicit()
                                               ? z_preferred_hugetlbfs_mountpoints