Messages in this thread | | | Date | Thu, 10 May 2007 17:04:54 +1000 | From | Nick Piggin <> | Subject | Re: swap-prefetch: 2.6.22 -mm merge plans |
| |
Ray Lee wrote: > On 5/9/07, Nick Piggin <nickpiggin@yahoo.com.au> wrote: > >> Ray Lee wrote: >> > On 5/9/07, Nick Piggin <nickpiggin@yahoo.com.au> wrote: >> > >> >> You said it helped with the updatedb problem. That says we should >> look at >> >> why it is going bad first, and for example improve use-once >> algorithms. >> >> After we do that, then swap prefetching might still help, which is >> fine. >> > >> > Nick, if you're volunteering to do that analysis, then great. If not, >> > then you're just providing a airy hope with nothing to back up when or >> > if that work would ever occur. >> >> I'd like to try helping. Tell me your problem. > > > Huh? You already stated one version of it above, namely updatedb. But
So a swapping problem with updatedb should be unusual and we'd like to see if we can fix it without resorting to prefetching.
I know the theory behind swap prefetching, and I'm not saying it doesn't work, so I'll snip the rest of that.
>> What's wrong with the use-once we have? What improvements are you talking >> about? > > > You said, effectively: "Use-once could be improved to deal with > updatedb". I said I've been reading emails from Rik and others talking > about that for four years now, and we're still talking about it. Were > it merely updatedb, I'd say us userspace folk should step up and > rewrite the damn thing to amortize its work. However, I and others > feel it's only an example -- glaring, obviously -- of a more pervasive > issue. A small issue, to be sure!, but an issue nevertheless.
It isn't going to get fixed unless people complain about it. If you cover the use-once problem with swap prefetching, then it will never get fixed.
>> I don't think it is about energy or being mean, I'm just stating the >> issues I have with it. > > > Nick, I in no way think you're being mean, and I'm sorry if I've given > you that impression. However, if you're just stating the issues you > have with it, then can I assume that you won't lobby against having > this experiment merged?
Anybody is free to merge anything into their kernel. And if somebody asks for my issues with the swap prefetching patch, then I'll give them :)
-- SUSE Labs, Novell Inc. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |