Messages in this thread | | | Date | Thu, 07 Mar 2002 14:23:21 -0800 | From | Andrew Morton <> | Subject | Re: [RFC] Arch option to touch newly allocated pages |
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Rik van Riel wrote: > > > So what *is* a solution. Well, there's only so much memory available. > > In either case a) or case b) we're "fairly" distributing that memory > > between all files. And that's the problem. *All* the files have too > > small a readahead window. Which points one at: we need to stop being > > fair. We need to give some files a good readahead window and others > > not. The "soft pinning" which I propose with GFP_READAHEAD and > > PG_readhead might have that effect, I think. > > Actually, it could boil down to something more: > > use-once reduces the VM to FIFO order, which suffers from > belady's anomaly so it doesn't matter much how much memory > you throw at it > > drop-behind will suffer the same problem once the readahead > memory is too large to keep in the system, but at least the > already-used pages won't kick out readahead pages
err.. Was there a fix in there somewhere, or are we stuck?
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