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Message-ID: <a8e1da0801152041m7f6ca5casf5a5a4147be7f65f@mail.gmail.com>
Date: Wed, 16 Jan 2008 12:41:50 +0800
From: "Dave Young" <hidave.darkstar@gmail.com>
To: "Johannes Berg" <johannes@sipsolutions.net>
Subject: Re: [PATCH for 2.6.24] fix workqueue creation API lockdep interaction
Cc: "Peter Zijlstra" <peterz@infradead.org>,
       "Linus Torvalds" <torvalds@linux-foundation.org>,
       "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
       "Ingo Molnar" <mingo@elte.hu>, "Oleg Nesterov" <oleg@tv-sign.ru>
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On Jan 15, 2008 9:04 PM, Johannes Berg <johannes@sipsolutions.net> wrote:
> Dave Young reported warnings from lockdep that the workqueue API
> can sometimes try to register lockdep classes with the same key
> but different names. This is not permitted in lockdep.
>
> Unfortunately, I was unaware of that restriction when I wrote
> the code to debug workqueue problems with lockdep and used the
> workqueue name as the lockdep class name. This can obviously
> lead to the problem if the workqueue name is dynamic.
>
> This patch solves the problem by always using a constant name
> for the workqueue's lockdep class, namely either the constant
> name that was passed in or a string consisting of the variable
> name.
>
> Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
> ---
> Please be careful with this patch, I haven't been able to test it so far
> because my powerbook doesn't have lockdep.

Hi,
Just for confirm, the warnings didn't trigger after applied your patch, thanks.

Regards
dave
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