Process Management

Another name for a process is a task.

How does the Linux kernel handle process management?

Linux implements the standard Unix process management APIs such as fork(), exec(), wait(), as well as standard POSIX threads.

The process is the core operating system abstraction. Process is a fundamental and crucial abstraction, at the heart of every modern operating system, and ultimately, we have operating systems altogether to run programs.

Linux stores and represents processes with task_struct and thread_info. In Linux, processes are created via fork() and ultimately clone().

New executable images are loaded into address space via the exec() family of system calls.

There’s a hierarchy of processes. Parents glean information about their deceased children via the wait() family of system calls.

Process ultimately dies forcefully or intentionally via exit().

Threads

It is often useful for the kernel to perform some operations in the background.

The kernel accomplishes these background operations via kernel threads - the standard processes that exist solely in kernel space.

What is the difference between threads and processes?

The significant difference between kernel threads and normal processes is that kernel threads do not have an address space. Their mm pointer, which points at their address space is NULL.