Re: [PATCH] mm: yield during swap prefetching

Andrew Morton
2006-03-08T01:21:25Z

Con Kolivas <kernel@kolivas.org> wrote:
>
> > but, but. If prefetching is prefetching stuff which that game will soon
> > use then it'll be an aggregate improvement. If prefetch is prefetching
> > stuff which that game _won't_ use then prefetch is busted. Using yield()
> > to artificially cripple kprefetchd is a rather sad workaround isn't it?
>
> It's not the stuff that it prefetches that's the problem; it's the disk
> access.

But the prefetch code tries to avoid prefetching when the disk is otherwise
busy (or it should - we discussed that a bit a while ago).

Sorry, I'm not trying to be awkward here - I think that nobbling prefetch
when there's a lot of CPU activity is just the wrong thing to do and it'll
harm other workloads.