Panic on rwtest


(Jiawei Zhao) #1

After submission, rwtest 1 and 2 shows following:
panic: Assertion failed: fla - prpage < PAGE_SIZE, at …/…/vm/kmalloc.c:984 (subpage_kmalloc),
could anyone please clarify what does it mean, please?


(Geoffrey Challen) #2

This usually means that you allocated some large variable on your stack. Kernel thread stacks on OS/161 are only 4K, meaning that you have to be careful about what you allocate on them.

Not sure why this would be happening now though… People usually hit this on ASST2.


(Jiawei Zhao) #3

Thanks a lot for the explanation, could you please give us some context to showcase the way rw-lock works? Just like the bounded buffer with condition variable, kind of confused implementing rw-lock.


(Geoffrey Challen) #4

I think that the interface is pretty descriptive. If you need more help, come to office hours.