AOKP Performance Control is an application (apk) you can download from here -> [APP] AOKP Performance control [stock / Cyanogen]
Here is my settings based on trusted sources i.e. Red Hat, IBM, XDA, etc. and currently using with my phone without any problem.
CPU Govenor: smartass v2 - balance between performance and battery drain.
I/O Scheduler: NOOP or SIO
Reference: [REF] CPU Governors and I/O Schedulers
Free Memory & SD Read Ahead
Free memory: 50 mb is the optimum value for 512MB RAM.
SD read ahead: 512 kb or your preferred value.
The goal for virtual memory settings is to make latency lower for better responsive and experience.
I've set dirty settings to lower value, make it write back to disk faster for more free memory instead of keeping it in memory for a longer time and caused I/O botttleneck when flush a large dirty pages to disk.