Messages in this thread | | | Date | Wed, 27 Oct 2021 12:28:24 -0700 | From | Jakub Kicinski <> | Subject | Re: [PATCH net-next] netdevsim: Register and unregister devlink traps on probe/remove device |
| |
On Wed, 27 Oct 2021 22:15:41 +0300 Leon Romanovsky wrote: > One of the outcomes is that such chain usually prevents from us to ensure > proper locking annotation. > > Let's take as an example devlink_trap_policers_register(). > In some drivers, it is called before device_register() and we don't need > any locks at all, because we are in initialization flow. > > In mlxsw, it is called during devlink reload, and we don't really need to > lock it too, because we were supposed to lock everything for the reload. > > However, for the mlxsw, we created devlink_trap_policers_register() to be > dynamic, so we must lock devlink->lock, as we don't know how other users > of this API will use it. > > In the reality, no one uses it dynamically except mlxsw and we stuck > with function that calls to useless lock without us able to properly > annotate it with an invitation to misuse. > > It is an example of layering problem, there are many more subtle issues > like this that require some cabal knowledge of proper locks to make it > is safe.
Now that you made me express my opinion I started feeling attached to my way of thinking :) Let me try to convert devlink core, netdevsim and nfp to devlink instance locking and see how far I can get...
| |