[OpenAFS] namei/inode fileserver performance tests

[chas williams]

since people have questioned my results i have run a more 'definitive'
test.  the test machine was an ultra 60 with two processors.  the
cache was configured to 150M.  /vicepa (18G) was on a seperate single disk
(with respect to the cache).  the test volume was 500M (although thats probably
not very relevant).  bonnie++ was run locally (on the fileserver) to reduce
variation from network load.

testing with bonnie++ (-s 256 -r 128) on an 'inode' fileserver shows:

Version 1.02c       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
nova           256M  1725  26  1676  13  1397  11  2108  25  2335   7  19.1   4
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16    71  27   745  90    85  15    72  28   522  79   124  15

the same test, same machine, substituting a 'namei' fileserver shows:

Version 1.02c       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
nova           256M  1056  16  1218   9   961   8  1805  21  1951   5  19.0   4
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16    40  16   739  91    36   6    40  15   523  79    27   3

so on the first set of tests ("raw" i/o performance) namei is (on the average)
74.3% slower.  no change on seek performance.  for file operations, only
create/delete operations seem to suffer -- to the tune of about 50%.

[of course, before you ask, is bonnie++ the right benchmark?  if you dont
like my answers feel free to run your own.]