Process and module management 8–29
Unit summary: Process and module management
Topic A In this topic, you learned that processes are running instances of programs. User
processes are associated with a particular user, while daemons are system processes
started and run by the kernel. You learned how to list processes and view process
dependencies. You learned that the /proc and /sys directories are dynamic lists of files
and directories that represent running processes and active components, respectively.
You also learned how to kill processes, that is, stop them from running.
Topic B In this topic, you learned that foreground processes run in a subshell and block further
activity in the parent shell. Background processes run in a subshell, but don’t block
their parent shell. You also managed process priority by setting nice and renice values.
Topic C In this topic, you learned that you can view kernel information with commands such as
uname. You also learned how to view files in the /proc directory to obtain system
information. You tuned the kernel by setting sysctl values. Finally, you learned how to
view, load, and unload kernel modules by using the modprobe and related commands.
1 True or false? A process is an executable application file stored on a disk.
False. That’s a program. A process is a running program.
2 Daemons are also known as __________.
3 Every process has a __________, which identifies the PID of the process that
PPID (parent process ID)
4 What is the PID of the init daemon?
5 True or false? PIDs are not assigned sequentially.
6 What command do you use to view the process tree with PIDs listed for each?
7 What would be output when you enter the ps aux command?
A list of processes, their PIDs, state, priority, CPU time, and user ID for all processes across all
8 What does it mean that the top command is “interactive”?
It doesn’t simply output information and stop. It continues to run, enabling you to enter commands
and view information until you stop it.
9 True or false? There are 64 different kill signals you can send to a process to stop it.
10 What is the name and number of the “absolute kill” signal?