On Fri, Oct 04, 2013 at 05:13:23PM +0200, Oleg Nesterov wrote: > Not sure I understand... > > percpu-rwsem will use exclusive mode, with or without the possible > improvements we can copy from cpuhp. sb_writers can probably use it > too (along with other helpers from percpu-rwsem we do not have yet).
Oh; I thought to have understood it would go away when you switched to the reader scheme from the hotplug bits. But thinking a little more; yes you'd still need something to serialize writers. > If you mean that the "raw" rcu_sync infrastructure will never have > more users, will I am not sure, it looks "natural". But I can not > know for sure. Right, so this would be something I'd forgo if there were no immediate users. We could always reconsider if there was one; but apparently percpu-rwsem is one.. > I am not trying saying this feature is "must have", of course it > is not. The only problem, I am a bit puzzled why you dislike it > that much. The reason I dislike it is because I feel we're now mixing two objects into one; one object doing mutual exclusion and one object being terribly smart with sync_rcu. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
