RFC: Change x86-64 maximum page size to 2MB

[H. J. Lu]

The current x86-64 maximum page size is 1MB. With the future
development, 2MB is better for performance. Using 2MB won't break
anything, except for up to 2MB gap in virtual address space per file,
instead of 1MB. x86-64 has 48 bits in virtual address space. It
shouldn't be an issue for most applications. I have a patch:

http://sourceware.org/ml/binutils/2005-05/msg00644.html

which can be used to implement "-z max-page-size=xxxx" so that people
can control maximum page size at the link time if they prefer different
maximum page size.


H.J.