Re: 6.18.13 iwlwifi deadlock allocating cma while work-item is active.

[Tejun Heo]

Hello,

On Tue, Mar 03, 2026 at 12:49:24PM +0100, Johannes Berg wrote:
> Fair. I don't know, I don't think there's anything that even shows that
> there's a dependency between the two workqueues and the
> "((wq_completion)events_unbound)" and "((wq_completion)events)", and
> there would have to be for it to deadlock this way because of that?
> 
> But one is mm_percpu_wq and the other is system_percpu_wq.
> 
> Tejun, does the workqueue code somehow introduce a dependency between
> different per-CPU workqueues that's not modelled in lockdep?

Hopefully not. Kinda late to the party. Why isn't mm_percpu_wq making
forward progress? That should in all circumstances. What's the work item and
kworker doing?

Thanks.

-- 
tejun