I needed to add a custom System Request (Sys Req or SysRq) to a linux kernel some time ago. While doing so, I dug deep into how it works and I thought I’d make a quick post about it. Here is a good SuperUser answer about what a SysRq is. You may also know about SysRq via REISUB. This post has three parts: how to raise a SysRq, how SysRq works (looking into kernel code), and how to add your own SysRq.
Huh, I never actually gave any thought to how the SysRq key works. Interesting thing to learn after all these decades, heh
Removed by mod
I actually don’t know nearly enough about OS design, and I’ve been toying with the idea of learning more for like 20 years now but never manage to get around to it. How’s that book hold up, considering it was (apparently?) published in '96? I’d assume a lot of the basics are still the same, and since it’s a book about the “evolution” of UNIX the historical parts will still be interesting in any case
Removed by mod
The BSD book does seem interesting from a historical perspective, BSD is one of Ye Olden UN*X distros after all. Thanks for the recommendations! I think I’ll try to get my hands on a dead trees version of the BSD book.
Oh and did you specifically mean “The Design and Implementation of the 4.4BSD Operating System”? Looks like there’s one for FreeBSD as well
Removed by mod
Singapore eh?
Could have just left me alone 😔
I’ll set aside a whole day for you to talk about me not liking Linus tech tips if you like.
Let’s dive deep!
Please refrain from harassing our users, keep whatever argument you have contained to the thread it started. Following and harassing users across communities/instances is not tolerated.
You will only be given a temporary ban of one week from our instance, but if it continues after that it will changed to a permanent ban.
What happened? You don’t want to talk endlessly anymore ?