[formerly_proven]

WILLNEED really just reads the entire file asynchronously into the page cache, at least on Linux.

[wtallis]

Is that still true if the size_t parameter to the madvise call is less than the entire file size? I would think that madvise hints could be issued at page granularity and not affect the entire mapping as originally allocated.

[shawnz]

With no limit? What if the file is huge, will it evict other things in the cache?