Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 19 Jun 2007 12:04:33 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: Change in default vm_dirty_ratio |
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On Tue, 19 Jun 2007, John Stoffel wrote: > > Shouldn't the vm_dirty_ratio be based on the speed of the device, and > not the size of memory?
Yes. It should depend on: - speed of the device(s) in question - seekiness of the workload - wishes of the user as per the latency of other operations.
However, nobody has ever found the required algorithm.
So "at most 10% of memory dirty" is a simple (and fairly _good_) heuristic. Nobody has actually ever ended up complaining about the change from 40% -> 10%, and as far as I know this was the first report (and it's not so much because the change was bad, but because it showed up on a benchmark - and I don't think that actually says anythign about anything else then the behaviour of the benchmark itself)
So are there better algorithms in theory? Probably lots of them.
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