Messages in this thread | | | Date | Sun, 08 Sep 2002 14:51:04 -0700 | From | Andrew Morton <> | Subject | Re: LMbench2.0 results |
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Hugh Dickins wrote: > > On Sun, 8 Sep 2002, Andrew Morton wrote: > > > > We need to find some way of making vm_enough_memory not call get_page_state > > so often. One way of doing that might be to make get_page_state dump > > its latest result into a global copy, and make vm_enough_memory() > > only get_page_state once per N invokations. A speed/accuracy tradeoff there. > > Accuracy is not very important in that sysctl_overcommit_memory 0 case > e.g. the swapper_space.nr_pages addition was brought in at a time when > it was very necessary, but usually overestimates now (or last time I > thought about it). The main thing to look out for is running the same > memory grabber twice in quick succession: not nice if it succeeds the > first time, but not the second, just because of some transient effect > that its old pages are temporarily uncounted. >
That's right - there can be sudden and huge changes in pages used/free.
So any rate limiting tweak in there would have to be in terms of number-of-pages rather than number-of-seconds. - 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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