On Mon, Nov 02, 2015 at 02:09:20PM -0800, Paul Turner wrote: > If we went this route, we could do something like: > > + * So in this case the scheduler does not provide an obvious full barrier; > but > + * the smp_store_release() in finish_lock_switch(), paired with the > control-dep > + * and smp_rmb() in try_to_wake_up() form a release-acquire pair and fully > + * order things between CPU0 and CPU1. > > Instead of having this, which is complete, but hard to synchronize > with the points at which it actually matters. Just use acquire and > release above, then at the actual site, e.g. in try_to_wake_up() > document how we deliver the acquire required by the higher level > documentation/requirements.
Right, which was most of the point of trying to introduce smp_cond_acquire(), abstract out the tricky cond-dep and rmb trickery so we can indeed talk about release+acquire like normal people ;-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
