On Wed, 2019-06-26 at 11:08 -0400, Steven Rostedt wrote: > On Fri, 21 Jun 2019 16:59:55 -0700 > "Paul E. McKenney" <paul...@linux.ibm.com> wrote: > > > I have no objection to the outlawing of a number of these sequences in > > mainline, but am rather pointing out that until they really are outlawed > > and eliminated, rcutorture must continue to test them in mainline. > > Of course, an rcutorture running in -rt should avoid testing things that > > break -rt, including these sequences. > > We should update lockdep to complain about these sequences. That would > "outlaw" them in mainline. That is, after we clean up all the current > sequences in the code. And we also need to get Linus's approval of this > as I believe he was against enforcing this in the past.
Was the opposition to prohibiting some specific sequence? It's only certain misnesting scenarios that are problematic. The rcu_read_lock/ local_irq_disable restriction can be dropped with the IPI-to-self added in Paul's tree. Are there any known instances of the other two (besides rcutorture)? -Scott
