Hacker News Reader

>With the proper BPF tracing scripts, I think we can validate that programs indeed avoids page faults

Sorry, I'm a little confused why this would be necessary? Like, sure, it's a nice to have on a CI as a basic sanity check but if you just invoke mlockall you'll end up with everything wired down and you're good to go regardless?

View on HN

Yeah you're right on that one. I probably over-extended the use case here as I'm still just learning about this and thus tried to apply it to everywhere. I guess one thing you can maybe do is to use CI to validate that mlockall indeed has been called, haha. That said it's probably overkill as other tools can probably do this too.

While on that thought experiment, perhaps in general if you can use BPF/USDT to help trace/debug RT programs? I'm thinking of being able to verify/visualize timing for better tracing? Or maybe there are already tools that existing that I don't really know how to use (like ftrace + trace compass, maybe)

mloclall () requires the application under check to call them such that the application process cannot modify memory pages.

Whereas ebpf allows instrumentation free enforcement. Plus, app devs do not need to be aware of this fact. This facilitate separate of responsibility in code and organization.

Reply on news.ycombinator.com