Linux Internals - Process Management

In this episode of the CyberGizmo we explore how the Linux Process Management works, how programs become processes, how LINUX manages these process, and the State Machine behind the curtain that keeps it all straight. Also how Linux uses fork and exec to create new processes.

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Music Used in this video
Licensed under Creative Commons: By Attribution 3.0 License

[rotrose]

These knowledge are the very thing I am hunger for as a sys admin. Please continue to share these deep talk of Linux.

[diegonayalazo]

Thanks DJ for sharing your knowledge in such a digestible way. You are an inspiration! Keep up the good work

[KipIngram]

This was a good one. I've been working through these for continuing education at work. Some of them are a little boring, just because I already know parts of all this (so that's no criticism - they'd be great for someone not familiar), but this one was on some details I hadn't delved into before. So thanks for a very clear presentation and keep up the great work! Stay safe!

[cleightthejw]

@DJ This is good stuff. I don't know how old these videos are but this is definitely more the 'education' stuff for guys like myself.

[ajaynair]

I have an interview tomorrow and this is very helpful!

[chandrakumar]

Thank you for such a wonderful explanation..

[GrooveMotionArena]

I am very much happy with the video...Thanks DJ Ware

[emcpadden]

Another great explanation, thank you!

[franklemanschik_de]

Nice introduction Tasks relativ scheduled are the best processes

[over]

The freaky thing (annoying) about zombies is that they don't or can't trap signals anymore. You find a defunct a.out because your program locked up somewhere, but you can't kill -9 it as it's already marked defunct. It gets even more freaky when the process you were trying to evict was a hung "mount" command, say due to a hung NFS mount point. You get fed up and kill the mount process, but you can't kill it as it's blocked in kernel space, the process disappears, you get your shell back, but the mount command stays as a defunct zombie for a while. Hung NFS mounts are evil.

[celinaamados]

These videos are awesome! Helping me refresh concepts and prepare for interviews. Do you have a link to these slides?

[jaykb]

I think the zombie process definition is not accurate. When a parent dies, its just a running orphan process which will be adopted by init. Zombie is when the child is already dead but it continues to use reasources - and the parent doesnt/canot do anything about it.

[RobinSingh-mdsh]

Thanks for the video. However I believe your description of zombie process is wrong and you actually described an orphaned process. What are your thoughts?

[cleightthejw]

comment 2
@DJ

Do you think you could do a video or so on how a protocol works with its functions on 2 machines(which is ultimately expanded beyond that)? Like when IP sends out to another device- what is the other side wating for or how does it know what to send back like which functions to use? Does that make sense?

Or if you are familiar with BGP (and I'm sure you are) how would that work on a 'smile level' (even overly simplified)?

Are those functions packed in the same 'while'/'for' loop or are they separate? How does the other device know which function to use to address what it is receiving and then send out (if necessary) and visa-versa? So basically 'how are they 'talking' to each other with knoledge of what they are saying/expecting?

DJ, I was saying this for video stuff- not to have you literally writing it all here. I'm sure that would take a while to do
Thank you

[anonymous.youtuber]

Hehe somehow you look some 20 years younger. The guru look was also ok though. 😉

[lunaeclipse]

im on my way on backend, am i doing right being ended up here?

[dimitardanov]

Thank you for the series. Much appreciated.

[trinadadtobago]

At 2.20ish you mentioned that each process will have a pid and this will be a number generated by the system. this number has a limit and then it will be recycled back through the numbers. can you please tell me what is that number (the limit) and also doco relating to that? Thank you.
Your content is excellent, please keep going esp with Internals... :)

[icewreck]

Awesome tutorials. Can you send a link to the slides ?

[waliabbas]

Thank you, your clear explanation has given me peace.