On Thu, Oct 01, 2015 at 08:09:09AM -0700, Paul E. McKenney wrote:

On Thu, Oct 01, 2015 at 02:24:40PM +0200, Peter Zijlstra wrote:

quoted

I must say I'm somewhat surprised by this level of relaxation, I had
expected to only loose SMP barriers, not the program order ones.

Is there a good argument for this?

Yes, when we say "relaxed", we really mean relaxed.  ;-)

Both the CPU and the compiler are allowed to reorder around relaxed
operations.

Is this documented somewhere, because I completely missed this part.