Re: [RFC][PATCH] introduce ptr_diff()

Andi Kleen
2010-08-19T13:39:28Z

On Thu, Aug 19, 2010 at 03:05:13PM +0200, Bernd Petrovitsch wrote:
> On Don, 2010-08-19 at 14:59 +0200, Andi Kleen wrote:
> > > If so, the warning seems valid as sizeof(struct page) is probably not
> > > (always) a power of 2. On a native build on x86_64 it is 56 bytes
> > > hereover.
> > > Hmm ....
> >
> > gcc just generats a mull with inverted value. mull is cheap on any
> > reasonable CPU. Please fix sparse.
>
> Not that I really know the code of sparse but what would be an
> acceptable condition (except plain simply disabling/removing the warning
> as such)?

I think acceptable would be to warn if the type is variable sized
(although I think gcc likely would error out in this case anyways)

-Andi
--
ak@linux.intel.com -- Speaking for myself only.