In particular, one of the first questions is "What is the fundamental difference between the kernel and a process?" It rejects "The kernel is a special process with elevated privileges" (which is essentially correct) and prefers "The kernel is not a process—it's the system itself that serves processes," which is sort of wrong? The kernel represents itself as a process (process zero), because kernel threads also need scheduling. And it is privileged, obviously.
> The kernel represents itself as a process (process zero)
This isn't true of any modern operating system. Kernel code isn't confined to a single process or even a limited number of processes. Transitioning to kernel mode doesn't necessitate switching to a dedicated process. Prior to the emergence of CPU speculative execution vulnerabilities, it was common for kernel code to be mapped directly into the virtual address spaces of userspace processes.
PID 0 is merely an implementation detail of the scheduler shared among many Unices. It doesn't function like a normal process, nor is it an accurate representation of how the large part of the kernel operates.
This article (and comment you’re replying to) is about Linux, which does represent its own threads as pid 0. Yes, there are concepts that aren’t threads. Nevertheless, in a very real sense the kernel is a special process zero.
Also in Chapter 6 1. What is the relationship between CPU state and kernel state?, it prefers "CPU is stateless; kernel manages state" instead of "They share state equally". I also wouldn't divide it down as "equally" as the kernel manages much more state, but CPUs have registers and cache lines so I wouldn't say they're stateless either.
> This is actually based on "The Kernel in The Mind" by Moon Hee Lee.
This looks like a really interesting resource. Can anybody here vouch for its accuracy or usefulness? I can't find a ton about it online. The fact that it's only published as a series of LinkedIn posts, or a PDF attached to a LinkedIn post, does not fill me with confidence - but I guess we can't expect kernel devs to know how to create websites?
In particular, one of the first questions is "What is the fundamental difference between the kernel and a process?" It rejects "The kernel is a special process with elevated privileges" (which is essentially correct) and prefers "The kernel is not a process—it's the system itself that serves processes," which is sort of wrong? The kernel represents itself as a process (process zero), because kernel threads also need scheduling. And it is privileged, obviously.
> The kernel represents itself as a process (process zero)
This isn't true of any modern operating system. Kernel code isn't confined to a single process or even a limited number of processes. Transitioning to kernel mode doesn't necessitate switching to a dedicated process. Prior to the emergence of CPU speculative execution vulnerabilities, it was common for kernel code to be mapped directly into the virtual address spaces of userspace processes.
PID 0 is merely an implementation detail of the scheduler shared among many Unices. It doesn't function like a normal process, nor is it an accurate representation of how the large part of the kernel operates.
This article (and comment you’re replying to) is about Linux, which does represent its own threads as pid 0. Yes, there are concepts that aren’t threads. Nevertheless, in a very real sense the kernel is a special process zero.
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Also in Chapter 6 1. What is the relationship between CPU state and kernel state?, it prefers "CPU is stateless; kernel manages state" instead of "They share state equally". I also wouldn't divide it down as "equally" as the kernel manages much more state, but CPUs have registers and cache lines so I wouldn't say they're stateless either.
The very first sentence of the guide is "It's not X—it's Y. It does Z". Safe to assume the entire thing is AI generated.
Can you please elaborate what exactly is the problem with the first sentence?
"The kernel isn't a process—it's the system. It serves user processes, reacts to context, and enforces separation and control."
This is actually based on "The Kernel in The Mind" by Moon Hee Lee. You are welcome to provide feedback.
> This is actually based on "The Kernel in The Mind" by Moon Hee Lee.
This looks like a really interesting resource. Can anybody here vouch for its accuracy or usefulness? I can't find a ton about it online. The fact that it's only published as a series of LinkedIn posts, or a PDF attached to a LinkedIn post, does not fill me with confidence - but I guess we can't expect kernel devs to know how to create websites?
Is it or is it not AI generated? That's all I said, and you didn't deny it.
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