On Thu, Apr 19, 2007 at 09:47:18PM -0700, William Lee Irwin III wrote: > On Thu, Apr 19, 2007 at 09:35:04AM -0700, Christoph Lameter wrote: > > This patchset modifies the core VM so that higher order page cache pages > > become possible. The higher order page cache pages are compound pages > > and can be handled in the same way as regular pages. > > The order of the pages is determined by the order set up in the mapping > > (struct address_space). By default the order is set to zero. > > This means that higher order pages are optional. There is no attempt here > > to generally change the page order of the page cache. 4K pages are effective > > for small files. > > Oh dear. Per-file pagesizes are foul. Better to fix up the pagecache's > radix tree than to restrict it like this.
How is this restrictive? This opens up much goodness to filesystems. I *want* to be able to use different radix tree index orders for different inodes in a single filesystem. Not just for data, either; XFS has metadata constructs larger than a page that mean we have to carry our own buffer cache around. Being able to use the page cache directly for these metadata constructs would enable us to remove a good chunk of code from XFS.... Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group - 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/
