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Inside Your OS: What is a Process Scheduler, and How Does it Work?
(2008)
https://www.informit.com/articles/article.aspx
@feloneouscat Note that it was written in 2008.
I'm not sure that changes anything, but sometimes context matters.
My first real-time kernel was written for a tiny (real tiny) microprocessor. We tried to sell it but it was too “cutting edge” (no one knew what to do with an RTX as no one was using them at the time).
This was in the early 90’s.
The first page of the article is wrong. The subsequent pages are a weird mix of “total BS” mixed with legitimate if weirdly phrased truth.
It’s a mess.
@estherschindler
“The Linux O(1) scheduler used a priority array—an array of run queues indexed by priority.”
Um. 30 years ago I wrote a real-time kernel that allowed 256 priorities and a single run queue. It’s actually faster to search one queue than multiple queues. Also you don’t have to look to see if the high priority queue is empty. With my queuing mechanism the next to run is always at the top of the queue.
This article is weird and biased towards x86.