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

[Greg KH]

On Wed, May 28, 2008 at 09:06:37AM -0700, Greg KH wrote:
> On Wed, May 28, 2008 at 09:48:40AM -0600, Matthew Wilcox wrote:
> > On Mon, May 26, 2008 at 11:59:34PM -0700, Andrew Morton wrote:
> > > If that semaphore is being used as a mutex then we should convert it to
> > > a mutex (dammit).
> > 
> > Right.
> > 
> > > Leaving it implemented as a semphore is not the proper way of
> > > suppressing the lockdep warnings.  It would be better to convert it to
> > > a mutex then add suitable (and suitably commented) open-coded lockdep
> > > annotations to suppress the runtime warnings.
> > 
> > We don't even have to go that far.  Here's all that's needed:
> > 
> > diff -u a/drivers/base/class.c b/drivers/base/class.c
> > --- a/drivers/base/class.c
> > +++ b/drivers/base/class.c
> > @@ -134,7 +134,7 @@
> >  	}
> >  }
> >  
> > -int class_register(struct class *cls)
> > +int __class_register(struct class *cls, struct lock_class_key *key)
> 
> Sorry, this will not work properly, as class_create() is now more
> commonly called, and it calls class_register() from within the driver
> core.  So there would be a lot of classes with the same "key" because of
> this.
> 
> So try changing class_create also.

Oh forget it, I'm messing around in this area anyway, so all of these
changes are not going to apply to tomorrow's -next tree at all.

I'll take this and get it working, give me a bit...

thanks,

greg k-h
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