Most of the deadlocks I've faced are with different proccesses/devices both waiting on reads from each end of a socket/uart/etc. I've taken to putting timeouts on read calls, though then you have to deal with legitimate long request cycles timing out.
I have anecdata from my gamedev work that people tend to make mistakes when threads are pinned to some CPUs. Normally, when only time is a variable people can understand what can happen in their code. What confuses them is that space where those threads execute can be already taken. If a thread that should make whole system progress fails to grab a time slice these deadlocks are hard to reason about. Granted that lock ordering is the basic technique and if system did not had it all bets are off.
