On Wed, Nov 14, 2007 at 03:59:39PM +0000, David Howells wrote: > Nick Piggin <npiggin@xxxxxxx> wrote: > > > Christoph Lameter has patches exactly to make PAGE_CACHE_SIZE larger than > > PAGE_SIZE, and they seem to work without much effort. I happen to hate the > > patches ;) but that doesn't change the fact that PAGE_CACHE_SIZE is > > relatively useful and it is not at all an ill-defined concept. > > Where, please? mm kernels? Floating around. I'm not saying it will even get upstream. It's just an example. > > Basically, anything that goes in the page cache is in units of > > PAGE_CACHE_SIZE, and nothing else. For filesystems it should be pretty > > easy... > > That depends on what the coverage of struct page is. I don't actually know > whether this is PAGE_SIZE or PAGE_CACHE_SIZE; I assumed it to be the former, > but from what you've said, I'm not actually sure. It can be pretty well any power of 2 from PAGE_SIZE upwards, with compound pages. None of the filesystems should really care at all. It's not even a new concept, hugetlbfs uses HPAGE_SIZE... - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
