What's the max file mapping size in 64bits machine

Question

I\'m new to 64-bits architecture. Could you tell me what\'s MAX file size supported by file mapping in 64 bits linux machine. I want to open more than 20GB files by file map

Answer 1

From the mmap(2) man page:

   void *mmap(void *addr, size_t length, int prot, int flags,
              int fd, off_t offset);

length is a size_t, which on 64-bit machines is 64 bits in length. Therefore yes, you can theoretically map a 20GB file.