Difference between capability and memory mapping

Adam Lackorzynski adam at os.inf.tu-dresden.de
Tue Sep 30 23:15:16 CEST 2014


On Mon Sep 29, 2014 at 13:24:56 -0400, Yuxin Ren wrote:
> I found in the kernel, the capability mapping and memory mapping have very
> similar code path.
> But I found their performance difference is around 1000 cycles.
> Is this true? If it is true, why do they have such large difference?
> If this gap does not make sense, it should be a bug in my test.

Hmm, yes, there can be a difference. Of course, the number depends on
the hardware. Which one was slower/faster? For example, for memory there
there could be the need to TLB flushes, so it could be slower than cap

Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/

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