On Wed, 12 Apr 2017 07:48:00 -0700 "Paul E. McKenney" <[email protected]> wrote:
> > > > Like this? (Untested, but builds at least some of the time.) > > > > > > Not like that... :-/ Update on its way. > > > > Perhaps more like this. Started rcutorture on it, will see how it goes. I just love the above discussion with yourself ;-) > > Do you need this patch? If so, I should do some more work on it to > eliminate the extra common-case branch on the scheduler fastpath. > Do I still need this patch? Maybe. :-) I changed my benchmark test to call cond_resched_rcu_qs() instead and that appears to fix the issue. But I'm not sure if there's any other kthread out there that just calls cond_resched() or schedule(). Actually, I think it is still a good idea to have it. I believe that it will still allow synchronize_rcu_tasks() to progress even if there's a kthread task that is constantly being woken up, and never sleeps when it calls schedule(), as it may always have the R state. -- Steve
