According to this[1] paper the fact, that you effectively double your data cache with 32bit pointers leads to a performance increase of up to 30% in real world applications. I don't believe the comparatively rare context switches caused by TLB management interrupts cause a speed penalty that high. Hence I still don't understand why people want desperately go to 64bit. Just because some kernel programmers find it too stressful to bother with some minor memory management details?

[1] http://www.sciencedirect.com/science/article/pii/S1877050913...