> I brought FreeBSD's ufs_dirhash into my -current tree and have
> seen some good improvements.
> ...

Whee, this makes a huge difference in my tests, as you indicated
it would.

Here's what my test system gets now:

...
pm>show
Current configuration is:
The base number of files is 20000
Transactions: 50000
Files range between 500 bytes and 9.77 kilobytes in size
Working directory: /u2
Block sizes are: read=3D512 bytes, write=3D512 bytes
Biases are: read/append=3D5, create/delete=3D5
Using Unix buffered file I/O
Random number generator seed is 42
Report format is verbose.
pm>run
Creating files...Done
Performing transactions..........Done
Deleting files...Done
Time:
        8 seconds total
        5 seconds of transactions (10000 per second)

Files:
        45093 created (5636 per second)
                Creation alone: 20000 files (10000 per second)
                Mixed with transactions: 25093 files (5018 per second)
        24789 read (4957 per second)
        25184 appended (5036 per second)
        45093 deleted (5636 per second)
                Deletion alone: 20186 files (20186 per second)
                Mixed with transactions: 24907 files (4981 per second)

Data:
        144.06 megabytes read (18.01 megabytes per second)
        271.87 megabytes written (33.98 megabytes per second)
pm>quit
0.594u 7.120s 0:07.94 97.1%  0+0k 79+87io 0pf+0w

For comparison, the old result was (with my patch):

...
Time:
        54 seconds total
        41 seconds of transactions (1219 per second)

Files:
        45093 created (835 per second)
                Creation alone: 20000 files (2500 per second)
                Mixed with transactions: 25093 files (612 per second)
        24789 read (604 per second)
        25184 appended (614 per second)
        45093 deleted (835 per second)
                Deletion alone: 20186 files (4037 per second)
                Mixed with transactions: 24907 files (607 per second)

Data:
        144.06 megabytes read (2.67 megabytes per second)
        271.87 megabytes written (5.03 megabytes per second)
pm>quit
0.747u 46.719s 0:54.16 87.6% 0+0k 13+323io 17pf+0w

Regards,

- H=E5vard