[ltt-dev] [RFC git tree] Userspace RCU (urcu) for Linux (repost)

[Linus Torvalds]

On Thu, 12 Feb 2009, Paul E. McKenney wrote:
> 
> In other words, you are arguing for using ACCESS_ONCE() in the loops,
> but keeping the old ACCESS_ONCE() definition, and declaring BF hardware
> broken?

Well, I _also_ argue that if you have a busy loop, you'd better have a 
cpu_relax() in there somewhere anyway. If you don't, you have a bug.

So I think the BF approach is "borderline broken", but I think it should 
work, if BF just has whatever appropriate cache flush in its cpu_relax.

			Linus