Messages in this thread |  | | Date | Tue, 12 Sep 2000 16:08:54 +0200 (CEST) | From | Andrea Arcangeli <> | Subject | Re: More on 2.2.18pre2aa2 |
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On Tue, 12 Sep 2000, Alan Cox wrote:
>Andrea - latency is time measured and perceived. Doing it time based seems to >make reasonable sense. I grant you might want to play with the weighting per
When you have a device that writes a request every two seconds you still want it not to seek all the time because this would mean to make it even slower. No? The point very is simple: if you want good latency buy a faster hardware (and with a faster hardware our current elevator can become even more aggressive than the 1/2 second thing). You can't workaround the slowness of a slow device by putting the elevator in function of time, that will only make the global system even slower.
BTW, about the rest of the proposal we're just doing that. It's just that we don't do that in function of time, but in function of how many requests are passing a certain request. When too many request passed a certain request, we stop further requests to pass it again. Simple. You control the "how many request can pass a request" factor via elvtune. Read and writes have different factors.
Andrea
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