Hello, I'm trying to isolate some cores to run a CPU-bound real-time task and even though I'm using rcu_nocbs and rcu_nocb_poll, I can see the rcuc threads wake up, and I get RCU stall warnings on the isolated core. As per the documentation, if I use rcutree.kthread_prio with a priority > my RT task, then the rcu stall does not happen. However I find it confusing: why are the rcuc threads woken up on the isolated cores despite using rcu_nocbs and rcu_nocb_poll? In my (very likely erroneous) understanding, I shouldn't have to fiddle with rcu priority... In other words, how come I get rcu stalls on cores that have no rcu callbacks? Thanks.
