Minimal progress on the stratified trees but some pointy haired issues came up that distracted me for a while.
Reviewed some small changes from Sam Ortiz that look pretty as far as getting SGI's discontigmem stuff to play happily in combination with removing ->virtual. It's not clear whether it will perform well as it apparently takes some doing (in terms of CPU cycles, the code is not that bad) to remap mem_map array indices to page frame number offsets. Hopefully that won't be too bad, but if it is, ->virtual is #ifdef'd and can be brought back by that method.
Tried to take a harder look at the discontigmem thing itself but there's quite a bit there to wade through. I think I'll be waiting for the separated patch so I don't need to guess at which chunk corresponds to which feature it's trying to implement. If it were smaller (which I'm not sure it can be) it'd be easier to get a full picture, but it'll only get smaller by becoming multiple patches.
Finally got a look at Pat's NUMA-Q discontigmem patch and was very impressed, the code was very clean and very readable. I'll have to take a harder look to be sure I've done due diligence with respect to it not breaking other things but it's very nice.
The hashing flamewar apparently degenerated to the name-calling level, though the name-caller does not have a particularly good reputation. I don't care. I'll continue collecting hash table metrics and their measurements from test runs. Sounds like I might be having a benchmark weekend. Again.