At 11:11 PM -0400 7/16/05, Matthew Miller wrote: >On Sat, Jul 16, 2005 at 02:22:51PM -0400, Tony Nelson wrote: >> I didn't want to try a million files. Creation and listing seem to be >> linear with the number of files, but rm seems quadratic. I think this >> indicates that in my current 2.6.12 FC3 kernel using Ext3 the directory >> data structure is still a list and not a tree. > >I get similar results with your script. But try "dumpe2fs | grep features" >on your filesystem and look for dir_index. (Mine has it.) Well, it's not so impressive, though maybe by comparison it's good. As I say, it acts no better than if it were using a linked list, even if it is using a tree. >Then, if you want, >try using tune2fs to turn it off and retry the test.... On a test (loopback) FS, with dir_index I get results similar to before, while without dir_index, file creation gets very slow fast (100000 files: 1010 s vs. 34 s), while listing is about the same, and deleting is faster. So indexing is (and was) being used, but it doesn't help as much as I would expect, and it is still better to have only a moderate number of files per directory. ____________________________________________________________________ TonyN.:' <mailto:tonynelson@xxxxxxxxxxxxxxxxx> ' <http://www.georgeanelson.com/>
