Messages in this thread | | | Date | Tue, 16 Nov 2004 18:28:41 -0800 | From | Andrew Morton <> | Subject | Re: [RFC] Making compound pages mandatory |
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Linus Torvalds <torvalds@osdl.org> wrote: > > > > On Tue, 16 Nov 2004, David Howells wrote: > > > > Do you have any objection to compound pages being made mandatory, even without > > HUGETLB support? > > I haven't really looked into it, so I cannot make an informed decision. > How big is the overhead? And what's the _point_, since we don't seem to > need them normally, but the code is there for people who _do_ need them?
Yes, it's just the single pointer chase. Probably that's the common case now, because everyone will be enabling hugepages on lots of architectures.
But still, the non-compound code is well tested too, and leaving it in place does make a little microoptimisation available to those who want it, so I don't see a reason yet to make compound pages compulsory.
So I'd suggest that we make compound pages conditional on a new CONFIG_COMPOUND_PAGE and make that equal to HUGETLB_PAGE || !MMU. - 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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