extern unsigned long dirty_background_bytes;
extern int vm_dirty_ratio;
extern unsigned long vm_dirty_bytes;
-extern int dirty_writeback_interval;
-extern int dirty_expire_interval;
+extern unsigned int dirty_writeback_interval;
+extern unsigned int dirty_expire_interval;
extern int vm_highmem_is_dirtyable;
extern int block_dump;
extern int laptop_mode;