Re: irq lock inversion

[Jens Axboe <jens.axboe@oracle.com>]

On Sun, Nov 08 2009, Ingo Molnar wrote:
> 
> * 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.

I think the primary problem is that it tries to condense too much
information, instead of just spelling it out. That may be obvious to a
person intimately familiar with lockdep, but not to others. Things like
the STATE line, for instance. It would read a lot easier if these things
were just spelled out.

I know this message isn't really productive, just tossing it out there.
I'll try to to back it up with a patch the next time it annoys me :-)

-- 
Jens Axboe