Here are my thoughts on the free online textbook Is Parallel Programming Hard, And, If So, What Can You Do About It? by Paul E. McKenney, author of the Linux kernel’s RCU synchronization mechanism. I read a lot of this textbook, got my fill, and probably won’t read more of it in the near future so wanted to write this review while it is all still fresh. Set & Setting Here I’ll talk about the mindset/life phase and physical setting I was in when I started reading this textbook. This might be like the tedious personal flavor preamble they have on recipe websites so skip ahead if that does not interest you.