Use std Mutex if your critical sections are short and you're not too worried about fairness.
Use parking_lot Mutex if you experience thread starvation and don't care about panic poisoning.

[–] MoSal@programming.dev 4 points 3 weeks ago

This, and similar posts discussing the same subject, seem to fail to realize that you can trivially implement your own back-off strategy using Mutex::try_lock(). This can have significant performance implications in use-cases where absolute low latency is not required.

I rarely see this get mentioned, although I think I did see it once or twice.

A shout out to the spin crate too, which has a lot of options that may interest people explicitly supported/exposed. It also supports no_std which can be immensely useful in some use-cases.