[PATCH v2] sched/core: fix illegal RCU from offline CPUs

[Qian Cai]

> On Apr 2, 2020, at 11:54 AM, Paul E. McKenney <paulmck at kernel.org> wrote:
> 
> I do run this combination quite frequently, but only as part of
> rcutorture, which might not be a representative workload.  For one thing,
> it has a minimal userspace consisting only of a trivial init program.
> I don't recall having ever seen this.  (I have seen one recent complaint
> about an IPI being sent to an offline CPU, but I cannot prove that this
> was not due to RCU bugs that I was chasing at the time.)

Yes, a trivial init is tough while running systemd should be able to catch it as it will use cgroup.