On Mon Apr 28, 2025 at 11:00 PM JST, Danilo Krummrich wrote: > This patch series implements a direct accessor for the data stored within > a Devres container for cases where we can prove that we own a reference > to a Device<Bound> (i.e. a bound device) of the same device that was used > to create the corresponding Devres container. > > Usually, when accessing the data stored within a Devres container, it is > not clear whether the data has been revoked already due to the device > being unbound and, hence, we have to try whether the access is possible > and subsequently keep holding the RCU read lock for the duration of the > access. > > However, when we can prove that we hold a reference to Device<Bound> > matching the device the Devres container has been created with, we can > guarantee that the device is not unbound for the duration of the > lifetime of the Device<Bound> reference and, hence, it is not possible > for the data within the Devres container to be revoked. > > Therefore, in this case, we can bypass the atomic check and the RCU read > lock, which is a great optimization and simplification for drivers. Thanks, this removes one of my pain points with the way revocable resources were accessed and will allow to write drivers in a much more natural way. FWIW, the series Reviewed-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
