On the other hand, Linus is one of a handful of people in the world who may be in a position to get results by yelling at Intel engineers to 'make it go faster!'. This isn't because Intel is too ignorant to do things on their own, but because practically everything can be optimized further, and Linus may have enough sway to focus the engineers' attention on the problem that he wants solved.
Personally, I don't care much about the speed of the Linux kernel build system, but I do care about the speed with which page faults are handled by the CPU. Even if the chances of success are lower, if he is able to succeed in speeding up every page fault on future Intel processors, I would consider that a much greater good.
The real problem (as I see it) is that I think he's trying to optimize the wrong thing. His worst-case test is based on trying to repeatedly fault in an uncacheable page: every lookup TLB lookup fails at every level of the cache. Likely, Intel has chosen to optimize the real situation where page translations are cached when they are repeatedly accessed.
Personally, I don't care much about the speed of the Linux kernel build system, but I do care about the speed with which page faults are handled by the CPU. Even if the chances of success are lower, if he is able to succeed in speeding up every page fault on future Intel processors, I would consider that a much greater good.
The real problem (as I see it) is that I think he's trying to optimize the wrong thing. His worst-case test is based on trying to repeatedly fault in an uncacheable page: every lookup TLB lookup fails at every level of the cache. Likely, Intel has chosen to optimize the real situation where page translations are cached when they are repeatedly accessed.