Lai Jianshan pulled off an interesting feat, locating a bug in rcu_barrier() by inspection and producing a very nice fix. The interesting part is that he produced the fix just in time for Frederic Weisbecker and perhaps Ingo Molnar as well.
Usually the fix comes after the bug is reproduced, not just in time!
paulmckrcu 
Hmm…
Hey don’t say it’s solved. We never know 😉
Re: Hmm…
True enough!!!