Re: [RFC][PATCH 2/7] kref: Add kref_read()

From: Peter Zijlstra
Date: Tue Nov 15 2016 - 02:47:18 EST


On Tue, Nov 15, 2016 at 08:28:55AM +0100, Greg KH wrote:
> On Mon, Nov 14, 2016 at 10:16:55AM -0800, Christoph Hellwig wrote:
> > On Mon, Nov 14, 2016 at 06:39:48PM +0100, Peter Zijlstra wrote:
> > > Since we need to change the implementation, stop exposing internals.
> > >
> > > Provide kref_read() to read the current reference count; typically
> > > used for debug messages.
> >
> > Can we just provide a printk specifier for a kref value instead as
> > that is the only valid use case for reading the value?
>
> Yeah, that would be great as no one should be doing anything
> logic-related based on the kref value.

IIRC there are a few users that WARN_ON() the value with a minimum bound
or somesuch. Those would be left in the cold, but yes I too like the
idea of a printk() format specifier.