I decided to take Dave's claim of XFS being ood for small systems seriously. The small system I have handy today is my Scientific Linux 6.1 desktop machine. Q660 Quad core processor. 4GB ram. A single 1.5TB 7200rpm seagate SATA disk. Scientific Linux 6.1 uses the latest RHEL 6.2 kernel (2.6.32-220.4.1.el6.x86_64), which Dave says has all the patches he covered in his talk.
I put it into runlevel 3 and disabled all unnecessary services. Set up a 25GB logical volume formatted XFS. Mounted with Dave's suggested options: inode64,logbsize=262144
I stopped the mixed workload test after 45 minutes. vmstat was reporting about 700k/s in, 2k/s out. The drive light was on solid. Iozone was using only a about 2% of processor. This seemed quite puzzling. Tried again. Same result. Switching from CFQ to Deadline or Noop i/o scheduler made no difference. No error messages in the log. And I was on a text console, so would have seen any kernel messages immediately.
I reformatted to ext4 and mounted with default options. I got these results: