Re: Unregistering interfaces

[Greg KH <greg@kroah.com>]

On Mon, Mar 29, 2004 at 03:31:17PM -0800, Andrew Morton wrote:
> Greg KH <greg@kroah.com> wrote:
> >
> > > The module should remain in memory, "unhashed", until the final kobject
> > > reference falls to zero.  Destruction of that kobject causes the refcount
> > > on the module to fall to zero which causes the entire module to be
> > > released.
> > > 
> > > (hmm, the existence of a kobject doesn't appear to contribute to its
> > > module's refcount.  Why not?)
> > 
> > It does, if a file for that kobject is opened.  In this case, there was
> > no file opened, so the module refcount isn't incremented.
> 
> hm, surprised.  Shouldn't the existence of a kobject contribute to its
> module's refcount?

No, a kobject by itself knows nothing about a module.  Only the
attribute files do (and they are the things that contain the struct
module *), as they are what user space can grab references to.

I never thought that the kobject would care, as it is only a directory,
and I didn't think that anything could grab directory references on
their own.  But then Maneesh's patch wasn't in the kernel at that time
:)

thanks,

greg k-h