This is where Schimmel’s book entered the chat. It was the first comprehensive guide on how to tear apart the UNIX kernel to make it run efficiently on multiple processors.
Unix systems in 1994 featured:
Here are a few references that might be useful for further reading: unix systems for modern architectures -1994- pdf
: How caches and multiprocessors work together, focusing on cache consistency. Online Availability and Access This is where Schimmel’s book entered the chat
// CPU B if (ready_flag) print(data); // On Alpha: prints 0, not 42 // On Alpha: prints 0
: While "modern" in 1994 referred to the dawn of Symmetric Multiprocessing (SMP) and CPU caches, reviewers note that today's systems are essentially the same architecture, just scaled up significantly.