On Fri, 2007-04-20 at 12:10 -0700, Christoph Lameter wrote: > On Fri, 20 Apr 2007, Dave Kleikamp wrote: > > Yeah. I'm working on patches for storing file tails in buffers > > allocated from the slab cache, and the tail will be represented by a > > fake struct page. (This is primarily for kernels with a larger page > > size). So my version of page_cache_size(page) may return a different > > size for different pages belonging to the same mapping. I'm in the > > midst of cleaning up the patches and plan to post them to linux-mm by > > Monday. > > I am not sure what the point of that patchset would be in this context > given that this is about support for arbitrary page sizes. If the > filesystem wants it then it can reduce the page size for small files. > > Different page sizes for one mapping may introduce high complexity into a > filesystem.
I'm trying to keep it from getting too complicated. > And we can already represent different page size. We have compound pages > support in the kernel. There are advantages to having a larger base page size, such as increased TLB reach. I'm specifically targetting kernels built with CONFIG_PPC_64K_PAGES, but other architectures could benefit. > page_cache_size(page) in terms of current code in mm is > > PAGE_SIZE << compound_order(page) I don't see page_cache_size() in linux-2.6.21-rc6-mm1. Is there something newer? Anyway, my patches are at a proof-of-concept stage. I look forward to more discussion when I post the patch set. Thanks, Shaggy -- David Kleikamp IBM Linux Technology Center - 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/
