src/hotspot/os/posix/os_posix.cpp

*** 237,247 ****
    return posix_fallocate(fd, offset, len);
  #endif
  }
  
  // Map the given address range to the provided file descriptor.
! char* os::map_memory_to_dax_file(char* base, size_t size, int fd) {
    assert(fd != -1, "File descriptor is not valid");
  
    // allocate space for the file
    if (util_posix_fallocate(fd, 0, (off_t)size) != 0) {
      vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory."));
--- 237,247 ----
    return posix_fallocate(fd, offset, len);
  #endif
  }
  
  // Map the given address range to the provided file descriptor.
! char* os::map_memory_to_file(char* base, size_t size, int fd) {
    assert(fd != -1, "File descriptor is not valid");
  
    // allocate space for the file
    if (util_posix_fallocate(fd, 0, (off_t)size) != 0) {
      vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory."));
*** 265,279 ****
      return NULL;
    }
    return addr;
  }
  
! char* os::replace_existing_mapping_with_dax_file_mapping(char* base, size_t size, int fd) {
    assert(fd != -1, "File descriptor is not valid");
    assert(base != NULL, "Base cannot be NULL");
  
!   return map_memory_to_dax_file(base, size, fd);
  }
  
  // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
  // so on posix, unmap the section at the start and at the end of the chunk that we mapped
  // rather than unmapping and remapping the whole chunk to get requested alignment.
--- 265,279 ----
      return NULL;
    }
    return addr;
  }
  
! char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
    assert(fd != -1, "File descriptor is not valid");
    assert(base != NULL, "Base cannot be NULL");
  
!   return map_memory_to_file(base, size, fd);
  }
  
  // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
  // so on posix, unmap the section at the start and at the end of the chunk that we mapped
  // rather than unmapping and remapping the whole chunk to get requested alignment.
*** 326,336 ****
        os::release_memory(extra_base + begin_offset + size, end_offset);
    }
  
    if (file_desc != -1) {
      // After we have an aligned address, we can replace anonymous mapping with file mapping
!     if (replace_existing_mapping_with_dax_file_mapping(aligned_base, size, file_desc) == NULL) {
        vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
      }
      MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
    }
    return aligned_base;
--- 326,336 ----
        os::release_memory(extra_base + begin_offset + size, end_offset);
    }
  
    if (file_desc != -1) {
      // After we have an aligned address, we can replace anonymous mapping with file mapping
!     if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
        vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
      }
      MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
    }
    return aligned_base;