Messages in this thread | | | Date | Tue, 9 Oct 2007 07:52:39 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: remove zero_page (was Re: -mm merge plans for 2.6.24) |
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On Tue, 9 Oct 2007, Nick Piggin wrote: > > I have done some tests which indicate a couple of very basic common tools > don't do much zero-page activity (ie. kbuild). And also combined with some > logical arguments to say that a "sane" app wouldn't be using zero_page much. > (basically -- if the app cares about memory or cache footprint and is using > many pages of zeroes, then it should have a more compressed representation > of zeroes anyway).
One of the things that zero-page has been used for is absolutely *huge* (but sparse) arrays in Fortan programs.
At least in traditional fortran, it was very hard to do dynamic allocations, so people would allocate the *maximum* array statically, and then not necessarily use everything. I don't know if the pages ever even got paged in, but this is the kind of usage which is *not* insane.
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