Re: [rfc][patch] store-free path walking

Linus Torvalds
2009-10-07T20:53:09Z

On Wed, 7 Oct 2009, Andi Kleen wrote:
>
> With some strategic prefetches it might be cheap enough to use
> two cache lines. Just fetch it with the other.

I _seriously_ doubt that.

This is one of the biggest (and hottest) hash tables in the whole kernel.

No amount of prefetching will help the fact that you effectively double
your cache footprint / working set if you have to fetch two cachelines in
the hot case lookup rather than one.

Linus