Messages in this thread | | | Date | Wed, 06 Oct 2004 15:00:05 +1000 | From | Nick Piggin <> | Subject | Re: Default cache_hot_time value back to 10ms |
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Andrew Morton wrote:
> This tunable caused an 11% performance difference in (I assume) TPCx. > That's a big deal, and people will want to diddle it. >
True. But 2.5 I think really is too low (for anyone, except maybe a CPU with no/a tiny L2 cache).
> If one number works optimally for all machines and workloads then fine. >
Yeah.. 10ms may bring up idle times a bit on other workloads. Judith had some database tests that were very sensitive to this - if 10ms is OK there, then I'd say it would be OK for most things.
> But yes, avoiding a tunable would be nice, but we need a tunable to work > out whether we can avoid making it tunable ;) >
Heh. I think it would be good to have a automatic thingy to tune it. A smarter cache_decay_ticks calculation would suit.
> Not that I'm soliciting patches or anything. I'll duck this one for now. >
OK. Any idea when 2.6.9 will be coming out? :) - 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/
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