-1994- Pdf ~repack~ — Unix Systems For Modern Architectures

: Features end-of-chapter exercises with selected answers and an appendix summarizing popular chips used in UNIX systems of that era.

In the early 90s, CPU speeds were outstripping memory bus speeds by orders of magnitude. A CPU might be able to execute an instruction in 5 nanoseconds, but fetching data from main RAM could take 100 nanoseconds. The solution was CPU caching—fast, expensive memory sitting directly next to the processor. unix systems for modern architectures -1994- pdf

// CPU B if (ready_flag) print(data); // On Alpha: prints 0, not 42 The solution was CPU caching—fast

While the title sounds ancient in an era of cloud computing and multi-core smartphones, the problems Schimmel addressed in 1994 are the exact same problems engineers face today. The book documents the difficult transition from single-processor systems to Symmetric Multiprocessing (SMP), a transition that fundamentally changed how operating systems are designed. // On Alpha: prints 0