On Tue, Jul 01, 2014 at 02:50:21PM -0400, Naoya Horiguchi wrote: > On Tue, Jul 01, 2014 at 09:07:39PM +0300, Kirill A. Shutemov wrote: > > Why do we need this special case for hugetlb page ->index? Why not use > > PAGE_SIZE units there too? Or I miss something? > > hugetlb pages are never split, so we use larger page cache size for > hugetlbfs file (to avoid large sparse page cache tree.)
For transparent huge page cache I would like to have native support in page cache radix-tree: since huge pages are always naturally aligned we can create a leaf node for it several (RADIX_TREE_MAP_SHIFT - HPAGE_PMD_ORDER) levels up by tree, which would cover all indexes in the range the huge page represents. This approach should fit hugetlb too. And -1 special case for hugetlb. But I'm not sure when I'll get time to play with this... -- Kirill A. Shutemov -- 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/
