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Date: Sun, 8 Nov 2009 10:38:59 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: Tejun Heo <tj@kernel.org>, Jiri Kosina <jkosina@suse.cz>,
       Peter Zijlstra <peterz@infradead.org>,
       Yinghai Lu <yhlu.kernel@gmail.com>,
       Thomas Gleixner <tglx@linutronix.de>, cl@linux-foundation.org,
       linux-kernel@vger.kernel.org
Subject: Re: irq lock inversion
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* Jens Axboe <jens.axboe@oracle.com> wrote:

> On Fri, Nov 06 2009, Ingo Molnar wrote:
> > Read the lockdep message please, consider all the backtraces it prints, 
> > it says something different.
> 
> In all honesty, reading and parsing lockdep messages requires a 
> special state of mind. IOW, readability is not its high point.

We frequently do patches to improve the messages but there's a hard 
limit: generally the messages mirror the complexity of the underlying 
locking scenario.

Unfortunately lockdep cannot pretend something is simple when it is not. 
There are two ways out of that: either to simplify the underlying 
locking rules, or to understand them.

	Ingo