Re: [PATCH v7 1/4] spinlock: A new lockref structure for locklessupdate of refcount

[Benjamin Herrenschmidt]

On Thu, 2013-08-29 at 19:35 -0700, Linus Torvalds wrote:
> That said, on power, you have that "ACCESS_ONCE()" implicit in the
> *type*, not in the code, so an "arch_spinlock_t" is fundamentally
> volatile in itself. It's one of the reasons I despise "volatile":
> things like volatility are _not_ attributes of a variable or a type,
> but of the code in question. Something can be volatile in one context,
> but not in another (one context might be locked, for example).

Right, we can probably change that to use ACCESS_ONCE... volatile tend
to never quite do what you expect anyway.

Cheers,
Ben.


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