On my machine, cap mapping is faster than memory.

I do not think there is tlb flush in memory mapping. It only happens when memory is unmapped, right?

But I found the mapping database for them are very different.

Cap mapping database is simpler than the memory's.

Thank you very much.

Yuxin

On Tue, Sep 30, 2014 at 5:15 PM, Adam Lackorzynski <adam@os.inf.tu-dresden.de> wrote:

Hi,

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
mappings.

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

_______________________________________________
l4-hackers mailing list
l4-hackers@os.inf.tu-dresden.de
http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers