The material looks fine for a quick refresher ... would need good books, in-depth stuff and code if you really want to learn OSes internals.

I think this type of content shouldn't be posted on HN. It's not news and it's been a long time since there was any shortage of study aids online.

I find these links very useful. HN seems to be serving a broader role than news,(another instance is the askhn posts). About non-shortage of online course material, this is very much true. Still, the 'aggregation' part remains - a way for users to post study notes that they find useful or interesting and then to discuss them.

Just don't up-vote. Its better to just rely on the voting system to describe the preferences of the community than to try to explain every user every nuance of what you think they should and should not post.

I'm interested in operating systems research and I haven't seen this before (perhaps only because I'm just getting started). So, this is useful to me; it may not be for you.

Besides, the biggest value of HN is not the links or 'news' posted here but the discussions around them.

Surely, not everything on HN is always useful to everyone. But on days when the front page isn't that appealing to me, it reminds me to get back to my work and try and apply what I've learned so far.

It from Martin Rinard who is god among men in modern operating systems research.

HN isn't just about "news news." This is part of the culture here. Most of us like it, I think. There's always TechCrunch ...