Re: [PATCH] lockdep: Show up to three levels for a deadlock scenario

[Steven Rostedt]

On Tue, 19 Dec 2017 11:54:10 -0500
Dhaval Giani <dhaval.giani@xxxxxxxxxx> wrote:

> On 2017-12-19 11:52 AM, Steven Rostedt wrote:
> > On Tue, 19 Dec 2017 17:46:19 +0100
> > Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> > 
> >   
> >> It really isn't that hard, Its mostly a question of TL;DR.
> >>
> >> #0 is useless and should be thrown out
> >> #1 shows where we take #1 while holding #0
> >> ..
> >> #n shows where we take #n while holding #n-1
> >>
> >> And the bottom callstack shows where we take #0 while holding #n. Which
> >> gets you a nice circle in your graph, which spells deadlock.
> >>
> >> Plenty people have shown they get this stuff.  
> > 
> > 
> > Then I suggest that you can either take my patch to improve the
> > visual or remove the visual completely, as nobody cares about it.
> >   
> 
> I prefer the former. As Steven has mentioned elsewhere, people find
> lockdep output hard to follow (enough that he has given talks :) )
> 

Not to mention. There's commit logs that throw everything out except
for this information. See commits:

 692b48258dda
 5acb3cc2c2e9
 7b7622bb95eb5
 478fe3037b227
 fdaf0a51bad49
 1ddd45f8d76f0
 63aea0dbab90a
 1215e51edad12
 f159b3c7cd45c

And those only go back to March of this year.

-- Steve