On Mon, 2 Apr 2007, Dave Hansen wrote:
I completely agree, it looks like it should be faster. The code
certainly has potential benefits. But, to add this neato, apparently
more performant feature, we unfortunately have to add code. Adding the
code has a cost: code maintenance. This isn't a runtime cost, but it is
a real, honest to goodness tradeoff.
Its just the opposite. The vmemmap code is so efficient that we can remove lots of other code and gops of these alternate implementations. On x86_64 its even superior to FLATMEM since FLATMEM still needs a memory reference for the mem_map area. So if we make SPARSE standard for all configurations then there is no need anymore for FLATMEM DISCONTIG etc etc. Can we not cleanup all this mess? Get rid of all the gazillions of #ifdefs please? This would ease code maintenance significantly. I hate having to constantly navigate my way through all the alternatives.