On Fri, 20 Apr 2007, Mel Gorman wrote: > So the difference here appears to be that specifying an order means you > can't mmap(). right? > > That's fair enough for the moment but relaxing would make ramfs > potentially usable as a replacement for hugetlbfs so there would be just > one ram-based filesystem instead of two.
Yes I have some draft of patches that enable mmap. But I think we should fist make the non mmap case work cleanly. The current approach is to map higher order pages into an address space on a per PTE basis. A page fault will establish one pte which may point to a tail page of a compound page. This means that the 4k semantics are preserved. We essentially manage pointers into 4k sections of larger pages. Later we could add support for PMD faults. If the page size is larger than pmd size then establish pmds mapping 2M instead of ptes. But that would be much much later when everything else works. - 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/
