Well, in some ways, even those can be solved with abstraction. The key is where that abstraction layer is placed. :) The assumption is you add them "on top" of what came before; but if you go in the other direction you may be able to improve performance by implementing, say, a smarter CPU with higher level abstractions built into the silicon. Things like that.
High level languages is also an example. C is really an abstraction layer upon machine code, but in most cases compilers produce faster code than what you would do if you wrote assembler. So C is an abstraction layer that helps you improve performance.
If a problem is so critical that one of its side-effects earns the title "the vietnam of computer science", then I think it is 'ok' to put "performance" considerations on a secondary tier and first see if there is a solution to the problem, in principle.
Well, in some ways, even those can be solved with abstraction. The key is where that abstraction layer is placed. :) The assumption is you add them "on top" of what came before; but if you go in the other direction you may be able to improve performance by implementing, say, a smarter CPU with higher level abstractions built into the silicon. Things like that.