The use case I'm thinking of is not random access over large files. It's using lots of very small files mmap()'ed so that you get the Linux VM helping you run a

The use case I'm thinking of is not random access over large files. It's using lots of very small files mmap()'ed so that you get the Linux VM helping you run an efficient cache. I've run across this with thumbnail caches in image processing software. It's easy for these kinds of things to be present in generally used libraries that your standard app will be using just because it has a GTK file selector for example. > you can mmap parts of a big file no problem with large file support in libc. For the speedups discussed here I definitely don't want to spend any time writing special code just to be able to read a 3GB file. That ship has long sailed and good riddance to all those subtle issues where things seem to work fine until they don't and it's not clear why.