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From: Tejun Heo <tj@kernel.org>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: Ben Greear <greearb@candelatech.com>,
	linux-wireless <linux-wireless@vger.kernel.org>,
	"Korenblit, Miriam Rachel" <miriam.rachel.korenblit@intel.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: 6.18.13 iwlwifi deadlock allocating cma while work-item is active.
Date: Tue, 3 Mar 2026 10:52:28 -1000	[thread overview]
Message-ID: <aadKDCKGHk1Ua-7_@slm.duckdns.org> (raw)
In-Reply-To: <35779061f94c2a55bb58dcd619ae91c618509cf4.camel@sipsolutions.net>

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


  reply	other threads:[~2026-03-03 20:52 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-23 22:36 Ben Greear
2026-02-27 16:31 ` Ben Greear
2026-03-01 15:38   ` Ben Greear
2026-03-02  8:07     ` Johannes Berg
2026-03-02 15:26       ` Ben Greear
2026-03-02 15:38         ` Johannes Berg
2026-03-02 15:50           ` Ben Greear
2026-03-03 11:49             ` Johannes Berg
2026-03-03 20:52               ` Tejun Heo [this message]
2026-03-03 21:03                 ` Johannes Berg
2026-03-03 21:12                 ` Johannes Berg
2026-03-03 21:40                   ` Ben Greear
2026-03-03 21:54                     ` Tejun Heo
2026-03-04  0:02                       ` Ben Greear

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