7 ms·
As an aside, it's shame that hardware page table walking won out over software filled TLBs, as some older computers had. I wonder what clever and wonderful hack
by quotemstr 2y ago
As an aside, it's shame that hardware page table walking won out over software filled TLBs, as some older computers had. I wonder what clever and wonderful hacks we might have been able to invent had we not needed to give the CPU a raw pointer to a data structure the layout of which is fixed forever.
- IshKebab 2y agoYeah maybe, though in practice I think it would be just too slow.
- zerohp 2y agoSoftware table walk performance is bad on modern out of order processors because it has to finish every older instruction in flight and redirect the front end to the exception vector. This can take several hundred cycles. Hardware table walk can take <20 cycles to hit in the next level cache.
- Denvercoder9 2y agoPage table layout isn't really fixed forever, x86 has changed its multiple times.
- quotemstr 2y agoNot without revving the hardware though