Dear Reader,

I decided to write a quick review for a book I read through while taking a Operating Systems course at Harvard Extension.  I’m currently re-reading through it and found it really useful.

Modern Operating Systems goes through basic components of a computer and talks about how the operating system interacts with it. Topics covered:

1. Processes, CPU and Scheduling.
2. Memory and Paging.
3. File System and I/O devices.  I/O section is split into block and character devices with smaller sub-sections on clocks.
4. Deadlocks and algorithms to resolve them.
5. Virtual Machines and Security.
6. Examples of Operating Systems: Android, Windows and Linux.

Currently about 50% through the book.  The book covers gets pretty detailed.  Topics in the book that I found really interesting:

1. Scheduling algorithms and how processes are swapped out by the CPU.
2. Mutex/Semaphores and the concept of locking a resource.
3. Different levels of caching involved in CPU, memory and file-system.
4. How memory, virtual memory and swapping works.
5. I/O devices: it gets into the details of a hard disk and breaks down what determines seek time.

I plan on getting through at least 20-30% more of the book as it provides some extra context for my job.  I spend a lot of time working with virtual machines (AWS) and have to look for problems like a pegged CPU or high-levels of memory consumption.  Understanding what happens under the covers from a operating system perspective is useful.

Best,

Chris