Hello John, Thursday, March 16, 2006, 4:00:34 AM, you wrote:
i suggest checking of AVAILABLE physical ram, that is perfectly possible in windows
JM> the problem is that available physical ram is wasted ram. any good os JM> will never let there be any available ram because it will fill it up JM> with disk buffers if nothing else. yes, but nevertheless really good operating systems report the avail ram what includes cache buffers. for not-so-good OSes disk cache can be a good measure ;) JM> the only time actual available ram JM> appears is when a big application quits, but then it quicky fills up due JM> to normal disk activity. determining how much of those buffers/cached JM> info you can push out without adversly affecting system performance or JM> thrashing is not very easy so at best we get a sort of approximation. John, not all algorithms are well determined. what we need is just to get "better behavior" in the most of cases JM> the best solution would be for ghc's garbage collector to periodically JM> call getrusage(2) and look at the number of page faults and swaps it is JM> causing and switch to compaction when it sees a jump in that. I don't JM> know what the equivalent routine on windows would be. not all operating JM> systems fill in all the values of getrusage, BSD is the best, linux is JM> the worst at this. but on linux you can get similar info from JM> /proc/self. (i think it does fill in the values we need in getrusage JM> though, I forget which ones it doesn't have) i agree tha this should be even better. windows have such mechanism. but it will be interesting if all our optimization tricks will work only with superuser privileges :) -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com