On Sat, Feb 28, 2015 at 09:36:15PM +0100, Manfred Spraul wrote: > +/* > + * Place this after a control barrier (such as e.g. a spin_unlock_wait()) > + * to ensure that reads cannot be moved ahead of the control_barrier. > + * Writes do not need a barrier, they are not speculated and thus cannot > + * pass the control barrier. > + */ > +#ifndef smp_mb__after_control_barrier > +#define smp_mb__after_control_barrier() smp_rmb() > +#endif Sorry to go bike shedding again; but should we call this: smp_acquire__after_control_barrier() ? The thing is; its not a full MB because: - stores might actually creep into it; while the control dependency guarantees stores will not creep out, nothing is stopping them from getting in; - its not transitive, and our MB is defined to be so. Oleg, Paul? -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html