[PATCH] ARM: change definition of cpu_relax() for ARM11MPCore

[Russell King - ARM Linux]

On Mon, Apr 12, 2010 at 06:23:58PM +0100, Will Deacon wrote:
> This patch changes the definition of cpu_relax() to smp_mb() for ARMv6 cores,
> forcing the write buffer to drain while inside a polling loop on an SMP system.
> If the Kernel is not compiled for SMP support, this will expand to a barrier()
> as before.

Linus asked how expensive (in terms of power rather than performance)
this was; so far that question has remained unanswered.  Can someone
please answer his question?