On Wed, 2013-10-09 at 15:56 -0700, Josh Triplett wrote: > I'd be really hesitant to introduce that type of direct assignment to an > __rcu pointer without wrapping it in some appropriately named macro, or > at the very least adding a comment.
Well, there is no special magic here, in this specific case : - deleting an item in an rcu list Check list_del_rcu(), and you'll notice there is no _barrier_ Adding correct barriers is good, but please do not add them when not needed. It makes code hard to understand. ACCESS(*ptr) = value; is clear and autodocumented, because it highlights the potential problem, that is *ptr can be read without any barrier from another cpu. So we ask the compiler to not write temporary garbage in it. rcu_assign_pointer(*ptr, rcu_access_pointer(value)) is very confusing, because it hides the _real_ problem and add defensive programming tricks. -- 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/
