Programs and memory
"If you’re willing to restrict the flexibility of your approach, you can almost always do something better."
– John Carmack
As a motivation to understand memory and its management, it's important for us to have a general idea of how programs are run by the operating system and what mechanisms are in place that allow it to use memory for its requirements.
Every program needs memory to run, whether it's your favorite command-line tool or a complex stream processing service, and they have vastly different memory requirements. In major operating system implementations, a program in execution is implemented as a process. A process is a running instance of a program. When we execute ./my_program in a shell in Linux or double-click on my_program.exe on Windows, the OS loads my_program as a process in memory and starts executing it, along with other processes, giving it a share of CPU and memory. It assigns the process with its own virtual address space, which is distinct from the...
