On Thu, 17 Mar 2005, Andrew Morton wrote: > OK, so we're splitting each zone's buddy structure into two: one for zeroed > pages and one for not-zeroed pages, yes?
Right. > It's not obvious what the page->private of freed pages are being used for. > Please comment that. Ok. > What's all this (zero << 10) stuff? > > + page->private = order + (zero << 10); > + (page_zorder(page) == order + (zero << 10)) && > > Doesn't this explode if we already have order-1024 pages in there? I guess > that's a reasonable restriction, but where did the "10" come from? > Non-obvious, needs commenting. Yes it will fail if we have pages of the size of 2^1036. > And given that we have separate buddy structures for zeroed and not-zeroed > pages, why is this tagging needed at all? Because the buddy pointers may point to a page of the different kind. Then a merge is not possible. > These are all design decisions which have been made, but they're not > communicated either in the patch description or in code comments. It's to > everyone's advantage to fix that, no? Of course. Try to do this ASAP. Testing a patch that defines the following: Index: linux-2.6.11/include/linux/gfp.h =================================================================== --- linux-2.6.11.orig/include/linux/gfp.h 2005-03-01 23:37:50.000000000 -0800 +++ linux-2.6.11/include/linux/gfp.h 2005-03-17 14:59:06.000000000 -0800 @@ -125,6 +125,8 @@ extern void FASTCALL(__free_pages(struct extern void FASTCALL(free_pages(unsigned long addr, unsigned int order)); extern void FASTCALL(free_hot_page(struct page *page)); extern void FASTCALL(free_cold_page(struct page *page)); +extern void FASTCALL(free_hot_zeroed_page(struct page *page)); +extern void FASTCALL(free_cold_zeroed_page(struct page *page)); #define __free_page(page) __free_pages((page), 0) #define free_page(addr) free_pages((addr),0) This is what you want right? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
