Efficient Go

Chapter 4. How Go Uses the CPU Resource (or Two)

One of the most useful abstractions we can make is to treat properties of our hardware and infrastructure systems as resources. CPU, memory, data storage, and the network are similar to resources in the natural world: they are finite, they are physical objects in the real world, and they must be distributed and shared between various key players in the ecosystem.

Susan J. Fowler, Production-Ready Microservices (O’Reilly, 2016)

As you learned in “Behind Performance”, software efficiency depends on how our program uses the hardware resources. If the same functionality uses fewer resources, our efficiency increases and the requirements and net cost of running such a program decrease. For example, if we use less CPU time (CPU “resource”) or fewer resources with slower access time (e.g., disk), we usually reduce the latency of our software.

This might sound simple, but in modern computers, these resources interact with each other in a complex, nontrivial way. Furthermore, more than one process is using these resources, so our program does not use them directly. Instead, these resources are managed for us by an operating system. If that wasn’t complex enough, especially in cloud environments, we often “virtualize” the hardware further so it can be shared across many individual systems in an isolated way. That means there are methods for “hosts” to give access to part of a single CPU or disk to a “guest” operating system that thinks it’s ...