FreeBSD MP Scalability Project

With the advent of readily affordable 32-thread hardware (sun4v), the starting goal of 4-processor scalability for the FreeBSD SMPng Project requires revision. This page is a work-in-progress todo list, and is not comprehensive.

1 Improve MUTEX_PROFILING - Measure contention times, not just counts; measure contention for spinlocks, sx locks, etc, not just mutexes.

2 Simplify locking in sleepqueues.

3 Determine how best to reduce runq lock contention.

4 Re-evaluate inlining decisions.

5 File descriptor lock contention.

6 General profiling of real-world workloads with > 8 cpus.

7 IPC lock granularity.