On Sat, Mar 21, 2020 at 10:49:04PM +0100, Thomas Gleixner wrote: [...] > >> +rwsems have grown interfaces which allow non owner release for special > >> +purposes. This usage is problematic on PREEMPT_RT because PREEMPT_RT > >> +substitutes all locking primitives except semaphores with RT-mutex based > >> +implementations to provide priority inheritance for all lock types except > >> +the truly spinning ones. Priority inheritance on ownerless locks is > >> +obviously impossible. > >> + > >> +For now the rwsem non-owner release excludes code which utilizes it from > >> +being used on PREEMPT_RT enabled kernels. > > > > I could not parse the last sentence here, but I think you meant "For now, > > PREEMPT_RT enabled kernels disable code that perform a non-owner release of > > an rwsem". Correct me if I'm wrong. > > Right, that's what I wanted to say :) > > Care to send a delta patch? Absolutely, doing that now. :-) thanks, - Joel