Linux @lemmy.ml learnbyexample @programming.dev 3w ago

What is PID 0?

blog.dave.tf What is PID 0? · blog.dave.tf

Yes, there's a PID 0! An explanation of what it is, and a quick walk through linux early boot code.

17 comments

It's unused, you can go ahead and kill it.
- Kernel: dies
ITT: people giving wrong answers to a post linked to a blog that answers the question 'What is PID 0?'
- For me it just gives an error post0 failed to load.
  
  Edit: that's probably my lemmy client trying to approach this blog as though it were a lemmy instance 🤦‍♂️
- Nonsense, yes. Isn't that what low effort posts (like nothing else but a link) are made for?
  
  You can call it low effort, but Lemmy is a "link aggregator". Even just sharing links has its value.
The tl;dr from the article (which is actually worth a read):

The very short version: Unix PIDs do start at 0! PID 0 just isn’t shown to userspace through traditional APIs. PID 0 starts the kernel, then retires to a quiet life of helping a bit with process scheduling and power management. Also the entire web is mostly wrong about PID 0, because of one sentence on Wikipedia from 16 years ago.
It's proportion integral derivative control of some functionality. Fans can use it.
- only fans? 😆
There is no PID 0. I guess I'll read the article.

Edit: This guy knows things
Mr. Anderson, Thank you for your analysis/work and well written treatise, on PID 0. I enjoyed learning more about Linux & Unix and a bit of history thereof as well.
- I read that in Agent Smith's voice.
  
  Happy cake day
The last time my community found a PID.0 in our midst, he was beaten downtown in broad daylight by over a dozen assailants, no witnesses.
- Plot twist: the assailants were holograms

17 comments