| Date | Thu, 27 May 2004 16:02:38 +1000 | From | Nick Piggin <> | Subject | Re: why swap at all? |
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Tom Felker wrote: > On Wednesday 26 May 2004 7:37 am, Matthias Schniedermeyer wrote: > > >>program to kernel: "i read ONCE though this file caching not useful". > > > Very true. The system is based on the assumption that just-used pages are > more useful that older pages, and it slows when this isn't true. We need > ways to tell the kernel whether the assumption holds. >
A streaming flag is great, but we usually do OK without it. There is a "used once" heuristic that often gets it right as far as I know. Basically, new pages that are only used once put almost zero pressure on the rest of the memory.
It has a few corner cases where it breaks down. Hopefully they can be improved... - 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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