On Wed, 09 Jun 2010 11:38:07 +0200 Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > On Wed, 2010-06-09 at 11:15 +0200, florian@xxxxxxxxxxx wrote: > > In order to have the pm_qos framework be callable from interrupt > > context, all listeners have to also be callable in that context. > > That makes no sense at all. Why add work structs _everywhere_ in the > callees and make the API harder to use and easy to get wrong completely, > instead of just adding a single work struct that will be queued from the > caller and dealing with the locking complexity etc. just once. > > johannes Just to defend this approach, but I'm certainly not married to it (hence RFC): There are only two listeners at the moment. I suspect that most future uses of the framework need to be atomic, as the driver that requests a specific quality of service probably doesn't want to get into races with the provider of that service(listener). So i suspected the network listener to be the special case. The race between service-provider and qos-requester for non-atomic contextes is already there, isn't it? so, locking complexity shouldn't be worse than before. But my first approach to this is seen here: https://lists.linux-foundation.org/pipermail/linux-pm/2010-June/026902.html A third possibility would be to make it dependent on the type of the constraint, if blocking notifiers are allowed or not. But that would sacrifice API consistency (update_request for one constraint is allowed to be called in interrupt context and update_request for another would be not). Cheers, Flo -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
