Aside from the two small comments, the pipe side looked reasonable, but I stopped looking when the patches moved on to the notificaiton part, and maybe I missed something in the earlier ones too. Which does bring me to the meat of this email: can we please keep the pipe cleanups and prepwork (and benchmarking) as a separate patch series? I'd like that to be done separately from the notification code, since it's re-organization and cleanup - while the eventual goal is to be able to add messages to the pipe atomically, I think the series makes sense (and should make sense) on its own. Linus