Martin Thompson on lock cost

Anything Martin Thompson says about performance is usually worth a good study. No exception is Locks & Condition Variables - Latency Impact.

His takeaway points:

1. The one-way latency to signal a change is pretty much the same as what is considered current state of the art for network hops between nodes via a switch.
2. The impact is clear when letting the OS choose what CPUs the threads get scheduled on rather than pinning them manually.