Re: [RT] 5.9-rt14 softirq_ctrl.lock vs listening_hash[i].lock lockdep splat

[Sebastian Andrzej Siewior]

On 2020-12-09 11:05:45 [+0100], Peter Zijlstra wrote:
> In general we have the rule that as long as a lock is only ever used
> from task context (like the above ilb->lock, afaict) then it doesn't
> matter if you also take it with (soft)irqs disabled or not. But this
> softirq scheme breaks that. If you ever take a lock with BH disabled,
> you must now always take it with BH disabled, otherwise you risk
> deadlocks against the softirq_ctrl lock.
> 
> Or am I missing something obvious (again) ?

No. With this explanation it makes sense. Thank you.

Sebastian