On Thu, Aug 23, 2007 at 12:33:06PM +1000, David Chinner wrote: > On Wed, Aug 22, 2007 at 09:18:41AM +0800, Fengguang Wu wrote: > > On Tue, Aug 21, 2007 at 08:23:14PM -0400, Chris Mason wrote: > > Notes: > > (1) I'm not sure inode number is correlated to disk location in > > filesystems other than ext2/3/4. Or parent dir? > > The correspond to the exact location on disk on XFS. But, XFS has it's > own inode clustering (see xfs_iflush) and it can't be moved up > into the generic layers because of locking and integration into > the transaction subsystem. > > > (2) It duplicates some function of elevators. Why is it necessary? > > The elevators have no clue as to how the filesystem might treat adjacent > inodes. In XFS, inode clustering is a fundamental feature of the inode > reading and writing and that is something no elevator can hope to > acheive.... Thank you. That explains the linear write curve(perfect!) in Chris' graph. I wonder if XFS can benefit any more from the general writeback clustering. How large would be a typical XFS cluster? -fengguang - 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
