Re: [RFC patch 08/18] cnt32_to_63 should use smp_rmb()

Andrew Morton
2008-11-07T17:28:37Z

On Fri, 07 Nov 2008 17:10:00 +0000 David Howells <dhowells@redhat.com> wrote:

>
> Andrew Morton <akpm@linux-foundation.org> wrote:
>
> > I'd expect it to behave in the same way as it would if the function was
> > implemented out-of-line.
> >
> > But it occurs to me that the modrobe-doesnt-work thing would happen if
> > the function _is_ inlined anyway, so we won't be doing that.
> >
> > Whatever. Killing this many puppies because gcc may do something so
> > bizarrely wrong isn't justifiable.
>
> With gcc, you get one instance of the static variable from inside a static
> (inline or outofline) function per .o file that invokes it, and these do not
> merge even though they're common symbols. I asked around and the opinion
> seems to be that this is correct C. I suppose it's the equivalent of cutting
> and pasting a function between several files - why should the compiler assume
> it's the same function in each?
>

OK, thanks, I guess that makes sense. For static inline. I wonder if
`extern inline' or plain old `inline' should change it.

It's one of those things I hope I never need to know about, but perhaps
we do somewhere have static storage in an inline. Wouldn't surprise
me, and I bet that if we do, it's a bug.