Re: [PATCH] Radix-tree pagecache for 2.5

[Anton Blanchard]

> That has some potential big wins beyond oracle. Some of the big number
> crunching algorithms also benefit heavily from 4Mb pages even when you
> try and minimise tlb misses.

There are further wins on some architectures, eg POWER has hardware
prefetch streams which terminate at a page boundary. With a 4kB pagesize
the prefetch engine will have to restart every 4kB, so we would want to
use 16MB pages if possible.

How would we allocate large pages? Would there be a boot option to
reserve an area of RAM for large pages only?

Anton