Le mercredi 07 avril 2010 à 17:19 +0100, David Howells a écrit : > Why not: > > ASSERT(atomic_read(&sk->sk_wmem_alloc) == 0); > filter = rcu_dereference(sk->sk_filter); > > This is much clearer, and you're not combining an unrelated assertion with the > RCU dereference. 1) Because we want the check being done only when CONFIG_PROVE_RCU is set. 2) Because rcu_dereference() default condition is : 'Am I owning rcu_read_lock() or equivalent'. In this context, I am _not_ owning rcu lock, so we will trigger a warning. So this is best done as is :) I personally find this very clear and clean, this is why I acked Paul patch :) If we were 100% sure testing sk_wmem_alloc is not necessary, we would have put : filter = rcu_dereference_check(sk->sk_filter, 1); -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
