Re: SLUB/debugobjects locking (Re: 2.6.27-rc4-git1: Reportedregressions from 2.6.26)

From: Ingo Molnar
Date: Thu Aug 28 2008 - 09:57:37 EST



* Vegard Nossum <vegard.nossum@xxxxxxxxx> wrote:

> On Wed, Aug 27, 2008 at 12:14 AM, Daniel J Blueman
> <daniel.blueman@xxxxxxxxx> wrote:
> > On Mon, Aug 25, 2008 at 8:44 PM, Vegard Nossum <vegard.nossum@xxxxxxxxx> wrote:
> >> I tried your suggestion of promoting the lock to irq-safe, and it
> >> fixed the warning for me (didn't get or look for deadlocks yet, but it
> >> seems likely that it is caused by the same thing?), the patch is
> >> attached for reference.
> >>
> >> I also don't know if this is the best fix, but I also don't have any
> >> other (better) suggestions.
> >>
> >> Others are welcome to pick it up from here...
> >
> > The solution looks like is needs to get the lock ordering correct
> > w.r.t. SLUB, as we get this, alas:
> >
> > =======================================================
> > [ INFO: possible circular locking dependency detected ]
> > 2.6.27-rc4-229c-debug #1
>
> Hm. Is this with my first patch + the one in the e-mail you replied
> to? It was intended to be a delta patch on top of my first one.
>
> That would be the one in
>
> http://marc.info/?l=linux-kernel&m=121946972307110&w=4
>
> plus the one in
>
> http://marc.info/?l=linux-kernel&m=121969394110327&w=1
>
> Thanks for testing and sorry for the confusion. (Maybe I just confused
> myself. Please let me know either way.)

could you resend the final patch please? It's a candidate for .27, if it
works out fine.

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/