You're never gonna be right 100% of the time when guessing how much buffer
space you need. This avoids having to make that type of decision in a bunch
of cases. :^)
Okay, now ProcFS doesn't crash due to the crappy buffer size estimates
not really working out. This thing has dogshit performance and I will
fix that separately.
The SpinLock was all backwards and didn't actually work. Fixing it exposed
how wrong most of the locking here is.
I need to come up with a better granularity here.