Declare device_type structure as const as it is only stored in the type field of a device structure. This field is of type const, so add const to declaration of device_type structure. File size before: text data bss dec hex filename 19278 3199 16 22493 57dd nvdimm/namespace_devs.o File size after: text data bss dec hex filename 19929 3160 16 23105 5a41 nvdimm/namespace_devs.o Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>