understanding applications and PAE

[Michael K. Johnson]

On Tue, Dec 09, 2003 at 12:00:38PM -0500, Nathan Bryant wrote:
> Sounds like you could treat /dev/shm as a large, linear file and mmap() 
> one window into it at a time...

And in RHEL3 and 2.6 kernel, that's what remap_file_pages is for -- a fast
remapping that doesn't trash vmas.  Quoting from mm/fremap.c:

* this syscall works purely via pagetables, so it's the most efficient
* way to map the same (large) file into a given virtual window. Unlike
* mmap()/mremap() it does not create any new vmas. The new mappings are
* also safe across swapout.

michaelkjohnson

 "He that composes himself is wiser than he that composes a book."
 Linux Application Development                     -- Ben Franklin
 http://people.redhat.com/johnsonm/lad/