Messages in this thread |  | | From | Daniel Phillips <> | Subject | Re: Linux VM design | Date | Mon, 24 Sep 2001 20:37:17 +0200 |
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On September 24, 2001 11:36 am, VDA wrote: > Daniel Phillips <phillips@bonn-fries.net> wrote: > DP> The arguments in support of aging over LRU that I'm aware of are: > > DP> - incrementing an age is more efficient than resetting several LRU > DP> list links > DP> - also captures some frequency-of-use information > > Of what use this info can be? If one page is accessed 100 times/second > and other one once in 10 seconds, they both have to stay in RAM. > VM should take 'time since last access' into account whan deciding > which page to swap out, not how often it was referenced.
You might want to have a look at this:
http://archi.snu.ac.kr/jhkim/seminar/96-004.ps (lrfu algorithm)
To tell the truth, I don't really see why the frequency information is all that useful either. Rik suggested it's good for streaming IO but we already have effective means of dealing with that that don't rely on any frequency information.
So the list of reasons why aging is good is looking really short.
-- Daniel - 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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