The benchmark: https://bitbucket.org/ivoras/stest/src/72b01c4d711cdfe75d37793c32faf098aea5dfec/open?at=default
Conclusion: the O_RDWR serialization might be a large contributor to blogbench being slow on FreeBSD.
Hardware: quad-core Xeon E3-1220, 3.1 GHz
| n_threads | ops/s |
| 1 | 785000 |
| 2 | 1170000 |
| 3 | 1570000 |
| 4 | 1880000 |
| 5 | 1860000 |
| 6 | 1890000 |
| 7 | 1890000 |
| 8 | 1920000 |
| 9 | 1920000 |
| n_threads | ops/s |
| 1 | 742000 |
| 2 | 1070000 |
| 3 | 1420000 |
| 4 | 1740000 |
| 5 | 1690000 |
| 6 | 1730000 |
| 7 | 1750000 |
| 8 | 1770000 |
| 9 | 1770000 |
| n_threads | ops/s |
| 1 | 307000 |
| 2 | 528000 |
| 3 | 659000 |
| 4 | 756000 |
| 5 | 711000 |
| 6 | 709000 |
| 7 | 710000 |
| 8 | 714000 |
| 9 | 705000 |
| n_threads | ops/s |
| 1 | 292000 |
| 2 | 297000 |
| 3 | 336000 |
| 4 | 321000 |
| 5 | 279000 |
| 6 | 247000 |
| 7 | 221000 |
| 8 | 206000 |
| 9 | 186000 |