From: Byungchul Park <byungchul.park@lge.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: mingo@kernel.org, linux-kernel@vger.kernel.org,
kernel-team@lge.com, Arnaldo Carvalho de Melo <acme@kernel.org>,
Dave Chinner <david@fromorbit.com>, Tejun Heo <tj@kernel.org>,
johannes@sipsolutions.net
Subject: Re: [PATCH v3 1/3] lockdep: Make LOCKDEP_CROSSRELEASE configs all part of PROVE_LOCKING
Date: Tue, 22 Aug 2017 14:14:38 +0900 [thread overview]
Message-ID: <20170822051438.GD20323@X58A-UD3R> (raw)
In-Reply-To: <20170821154600.asyzqs2zg6w6o4pg@hirez.programming.kicks-ass.net>
On Mon, Aug 21, 2017 at 05:46:00PM +0200, Peter Zijlstra wrote:
> Now given the above observance rule and the fact that the below report
> is from the complete, the thing that happened appears to be:
>
>
> lockdep_map_acquire(&work->lockdep_map)
> down_write(&A)
>
> down_write(&A)
> wait_for_completion(&C)
>
> lockdep_map_acquire(&work_lockdep_map);
> complete(&C)
>
> Which lockdep then puked over because both sides saw the same work
> class.
>
> Byungchul; should we not exclude the work class itself, it appears to me
> the workqueue code is explicitly parallel, or am I confused again?
Do you mean the lockdep_map_acquire(&work->lockdep_map) used manuallly?
That was introduced by Johannes:
commit 4e6045f134784f4b158b3c0f7a282b04bd816887
"workqueue: debug flushing deadlocks with lockdep"
I am not sure but, for that purpose, IMHO, we can use a
lockdep_map_acquire_read() instead, in process_one_work(), can't we?
next prev parent reply other threads:[~2017-08-22 5:14 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-17 8:57 Byungchul Park
2017-08-17 8:57 ` [PATCH v3 2/3] lockdep: Reword title of LOCKDEP_CROSSRELEASE config Byungchul Park
2017-08-17 10:21 ` [tip:locking/core] locking/lockdep: " tip-bot for Byungchul Park
2017-08-17 8:57 ` [PATCH v3 3/3] lockdep: Rename LOCKDEP_COMPLETE config Byungchul Park
2017-08-17 10:22 ` [tip:locking/core] locking/lockdep: Rename CONFIG_LOCKDEP_COMPLETE to CONFIG_LOCKDEP_COMPLETIONS tip-bot for Byungchul Park
2017-08-17 10:21 ` [tip:locking/core] locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE part of CONFIG_PROVE_LOCKING tip-bot for Byungchul Park
2017-08-17 10:45 ` Ingo Molnar
2017-08-18 5:33 ` Byungchul Park
2017-08-21 15:46 ` [PATCH v3 1/3] lockdep: Make LOCKDEP_CROSSRELEASE configs all part of PROVE_LOCKING Peter Zijlstra
2017-08-22 5:14 ` Byungchul Park [this message]
2017-08-22 7:52 ` Peter Zijlstra
2017-08-22 8:51 ` Byungchul Park
2017-08-22 9:21 ` Peter Zijlstra
2017-08-22 9:33 ` Byungchul Park
2017-08-22 10:08 ` Peter Zijlstra
2017-08-22 13:49 ` Peter Zijlstra
2017-08-22 14:46 ` Peter Zijlstra
2017-08-22 15:10 ` Peter Zijlstra
2017-08-22 15:59 ` Oleg Nesterov
2017-08-22 16:35 ` Peter Zijlstra
2017-08-23 16:39 ` Oleg Nesterov
2017-08-23 17:47 ` Peter Zijlstra
2017-08-24 6:11 ` Byungchul Park
2017-08-24 7:37 ` Byungchul Park
2017-08-24 8:11 ` Byungchul Park
2017-08-25 1:14 ` Byungchul Park
2017-08-29 15:52 ` Oleg Nesterov
2017-08-29 17:07 ` lockdep && recursive-read Oleg Nesterov
2017-08-29 17:30 ` Peter Zijlstra
2017-08-29 17:51 ` [PATCH v3 1/3] lockdep: Make LOCKDEP_CROSSRELEASE configs all part of PROVE_LOCKING Peter Zijlstra
2017-08-23 2:43 ` Byungchul Park
2017-08-23 6:31 ` Byungchul Park
2017-08-23 10:26 ` Peter Zijlstra
2017-08-24 5:07 ` Byungchul Park
2017-08-22 5:46 ` Dave Chinner
2017-08-22 9:06 ` Peter Zijlstra
2017-08-22 9:22 ` Byungchul Park
2017-08-22 9:37 ` Peter Zijlstra
2017-08-22 9:42 ` Peter Zijlstra
2017-08-23 2:12 ` Byungchul Park
2017-08-23 6:03 ` Byungchul Park
2017-08-23 10:20 ` Peter Zijlstra
2017-08-24 2:02 ` Byungchul Park
2017-08-24 7:30 ` Byungchul Park
2017-08-22 21:19 ` Dave Chinner
2017-08-23 2:31 ` Byungchul Park
2017-08-23 6:11 ` Byungchul Park
2017-08-23 10:46 ` Peter Zijlstra
2017-08-24 5:06 ` Byungchul Park
2017-08-23 1:56 ` Byungchul Park
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