Messages in this thread | | | Date | Thu, 22 Mar 2007 08:06:44 +0100 | From | Jarek Poplawski <> | Subject | Re: [PATCH] lockdep: lockdep_depth vs. debug_locks Re: [2.6.20] BUG: workqueue leaked lock |
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On Wed, Mar 21, 2007 at 10:28:02PM -0800, Andrew Morton wrote: > On Thu, 22 Mar 2007 07:11:19 +0100 Jarek Poplawski <jarkao2@o2.pl> wrote: > > > > > Here is some joke: > > > > [PATCH] lockdep: lockdep_depth vs. debug_locks > > > > lockdep really shouldn't be used when debug_locks == 0! > > > > This isn't a very good changelog. > > > > > Reported-by: Folkert van Heusden <folkert@vanheusden.com> > > Inspired-by: Oleg Nesterov <oleg@tv-sign.ru> > > Signed-off-by: Jarek Poplawski <jarkao2@o2.pl> > > > > --- > > > > diff -Nurp 2.6.21-rc4-git4-/include/linux/lockdep.h 2.6.21-rc4-git4/include/linux/lockdep.h > > --- 2.6.21-rc4-git4-/include/linux/lockdep.h 2007-03-20 20:24:17.000000000 +0100 > > +++ 2.6.21-rc4-git4/include/linux/lockdep.h 2007-03-21 22:32:41.000000000 +0100 > > @@ -245,7 +245,7 @@ extern void lock_release(struct lockdep_ > > > > # define INIT_LOCKDEP .lockdep_recursion = 0, > > > > -#define lockdep_depth(tsk) ((tsk)->lockdep_depth) > > +#define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) > > > > #else /* !LOCKDEP */ > > > > What problem does this solve, and how does it solve it? > > I assume that some codepath is incrementing ->lockdep_depth even when > debug_locks==0. Isn't that wrong of it? >
This should definitely solve this problem - as it was said a few times before lockdep stops registering locks after a bug, so even the lock which caused the warning isn't reported. Here lockdep found a bug in a workqueue function, so after this no lock or unlock isn't counted nor reported.
I think Ingo can tell more.
Regards, Jarek P. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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