Date: Fri, 7 Nov 2008 09:26:43 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: David Howells <dhowells@redhat.com>
Cc: Nicolas Pitre <nico@cam.org>,
       Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Ingo Molnar <mingo@elte.hu>, Peter Zijlstra <a.p.zijlstra@chello.nl>,
       linux-kernel@vger.kernel.org, Ralf Baechle <ralf@linux-mips.org>,
       benh@kernel.crashing.org, paulus@samba.org,
       David Miller <davem@davemloft.net>, Ingo Molnar <mingo@redhat.com>,
       Thomas Gleixner <tglx@linutronix.de>,
       Steven Rostedt <rostedt@goodmis.org>, linux-arch@vger.kernel.org
Subject: Re: [RFC patch 08/18] cnt32_to_63 should use smp_rmb()
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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.
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