Understanding PID Management in Linux（pidlinux）

PID（Process Identification） control system is the primary method of managing processes on a Linux system. It’s a system that allows Linux to identify running processes and manage them based on the process ID or “PID” assigned to each one. Understanding how the PID management system works is an important skill for any user of Linux.

At a basic level, PID management involves assigning a unique identifying number to each process running on the system. This number is known as the process ID, or PID for short. The PID assigning system can be used to track individual processes and their associated tasks, identify and manage resources being used by a specific process, and terminate running processes.

When you run a program, the Linux kernel assigns it a unique PID to track the process. This number is then used to associate additional information about the process with its PID. This can include the process size, the amount of memory it requires, the amount of resources it’s using, and any related processes and tasks.

The main way to interact with PID management is through the ps and kill commands. The ps command will list all the processes running on the system and their associated PIDs. Knowing the process PID, you can then use the kill command to terminate the process. Other commands such as top, killall, and pkill can also be used to manage processes.

When PID management goes wrong, it can cause system instability and crashes. If a process has been running for too long, it can accumulate a large number of PIDs. As the number of assigned PIDs increases, the system becomes stressed and performance suffers. In cases like this, it’s a good idea to use the ps command to list all the PIDs that are running on the system and then kill the process with the highest number of associated PIDs to free up the most resources.

Understanding how the Linux PID management system works is important for any Linux user. It’s a way to manage running processes in a safe and efficient manner and is key to keeping your system running quickly and reliably. Understanding the ps and kill commands and how to use them in combination can help users effectively manage processes and keep their system performing its best.