My takeaways from this:
- Kernel 3.2 is in fact lethally bad.
- Kernel 3.13 is the best out of kernel 3.X so far. I hope that this can be credited to the PostgreSQL team's work with the LFS/MM group.
- No 3.X kernel yet has quite the throughput of 2.6.32, at least at moderate memory sizes and core counts.
- However, kernel 3.13 has substantially lower write volumes at almost the same throughput. This means that if you are write-bound on IO, 3.13 will improve your performance considerably.
- If your database is mostly-reads and highly concurrent, consider enabling