On Thu, Jul 07, 2011 at 02:09:18PM +0200, Lennert Buytenhek wrote:

On Mon, Jun 27, 2011 at 03:19:43PM +0200, Arnd Bergmann wrote:

quoted

quoted

quoted

I suppose for the majority of the cases, the overhead of the indirect
function call is near-zero, compared to the overhead of the cache
management operation, so it would only make a difference for coherent
systems without an IOMMU. Do we care about micro-optimizing those?

FWIW, when I was hacking on ARM access point routing performance some
time ago, turning the L1/L2 cache maintenance operations into inline
functions (inlined into the ethernet driver) gave me a significant and
measurable performance boost.

On what architecture?  Can you show what you did to gain that?