Re: [PATCH 1/3][-mm] add class_reclassify macro

[Andrew Morton]

On Tue, 20 May 2008 19:05:21 +0800 "Dave Young" <hidave.darkstar@xxxxxxxxx> wrote:

> On Tue, May 20, 2008 at 6:02 PM, Andrew Morton
> <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> > On Tue, 20 May 2008 17:55:54 +0800 Dave Young <hidave.darkstar@xxxxxxxxx> wrote:
> >
> >> Converting class semaphore to mutex cause lockdep warnings due to
> >> class_interface_register/unregister will possible call device_add/del
> >
> > Shouldn't we just fix that?
> 
> Andrew, could you tell more?

Well what are these lockdep warnings?  Normally such a warning means that
we have a locking bug. I _assume_ that you've determined that the warnings
are false-positives?

The warning which Mariusz Kozlowski discovered ("Subject: Re:
2.6.26-rc2-mm1: possible circular locking dependency detected") was
triggered by the "class semaphore to mutex" conversion and it looks
like a real bug to me.  Would your patch prevent warnings such as that
one from being available to us?

--
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/