What are the benefits of mappi

Mapping objects into virtual memory greatly eases the sharing of data between processes.Rather than opening a file,locking access to it,and reading and writing sections via the I/O system calls,memory-mapped objects are accessible as "normal" memory,with reads and writes to locations independent of disk pointers..Loc king is mud h easier also,since one shared memory location can be used as a locking variable for semaphore access.Unfortunately,memory mapping adds complexity to the operating system,especially in a distributed system.