On Tue, Apr 30, 2019 at 04:15:01PM +0200, Oleg Nesterov wrote: > Sorry, I don't understand... So the problem is that on -RT rwsem uses PI mutexes, and the below just cannot work. Also see: https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/tree/include/linux/rwsem_rt.h?h=linux-5.0.y-rt https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/tree/kernel/locking/rwsem-rt.c?h=linux-5.0.y-rt > On 04/30, Peter Zijlstra wrote: > > > > Thaw then does the reverse, frobs lockdep > > Yes, in particular it does > > lockdep_sb_freeze_acquire() > percpu_rwsem_acquire() > sem->rw_sem.owner = current; > Oh ARGGH, I missed that. This is horrible :-(
