Re: How git affects kernel.org performance

On Mon, Jan 08, 2007 at 07:58:19AM -0500, Theodore Tso wrote:

The fastest and probably most important thing to add is some readahead
smarts to directories --- both to the htree and non-htree cases.  If
you're using some kind of b-tree structure, such as XFS does for
directories, preallocation doesn't help you much.  Delayed allocation
can save you if your delayed allocator knows how to structure disk
blocks so that a btree-traversal is efficient, but I'm guessing the
biggest reason why we are losing is because we don't have sufficient
readahead.  This also has the advantage that it will help without
needing to doing a backup/restore to improve layout.

Would e2fsck -D help? What kind of optimization
does it perform?


Thanks,
Johannes