Re: [PATCH 2.6.19-rc1-mm1] Export jiffies_to_timespec()

[Christoph Hellwig <hch@infradead.org>]

On Wed, Oct 11, 2006 at 11:17:39AM -0700, Andrew Morton wrote:
> On Wed, 11 Oct 2006 17:16:28 +0100
> Christoph Hellwig <hch@infradead.org> wrote:
> 
> > On Tue, Oct 10, 2006 at 05:36:54PM -0700, Jeremy Fitzhardinge wrote:
> > > Export jiffies_to_timespec; previously modules used the inlined header 
> > > version.
> > 
> > NACK, drivers shouldn know about these timekeeping details and no
> > in-tree driver uses it (fortunately)
> 
> Disagree.
> 
> a) `jiffies' and `timepsec' are hardly "details".  They are basic
>    kernel-wide concepts.  timespecs are even known to userspace.  Exporting
>    a helper function which converts from one to the other is perfectly
>    reasonable.

That non one in tree ever uses it is a very good reason no to export it
either.  While there are still far too many direct jiffy users there
is no one directly convertin it to a timespec for good reason.

> 
> b) jiffies_to_timespec() was previously available to modules.  We
>    changed that without notice and we changed it *by accident*.  There was
>    no intention to withdraw jiffies_to_timespec() from the
>    available-to-modules API.

By that rationale everything errornously implemented as a macro or inline
at some point will need to be exported.  Except for you we still maintain
that we don't want to keep unused exports.  Arjan even put a formal mechanism
in to warn about them and has gotten a global buy-in to kill them.  This
will fall under this ASAP and only give people a short period to keep using
it.  Not a very useful message.

(especially when the only user is closed source crap where people should
help the proper reverse-engineered driver instead)