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Subject: Re: [PATCH 1/2] Add thread_info_cache_init() to all archs
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Date: Wed, 21 May 2008 13:56:25 -0400
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On Fri, 2008-04-18 at 16:44 +1000, Benjamin Herrenschmidt wrote:
> > > so what
> > > about the patch below ?
> > 
> > I like it, but the compiler won't ;)
> > 
> > > If you're ok, I'll re-send with appropriate sob
> > > & adapted powerpc part.
> > 
> > Sure.
> > 
> > > +void __init __attribute__((weak) thread_info_cache_init(void)
> >

Back to this old subject...

I'm having reports that this is not working...

gcc is seeing the empty weak function and is optimizing it out
before it gets a chance to link to the arch provided one.

This would affect that and the other one next to it..

That seems pretty bad... it causes nasty crashes as we end up having no
idea what the compiler decided to generate... I suppose we could keep
the weak stubs out of the file where they are called but that sucks.

ie. This is some form of gcc 4.1.1

Is that a known problem ? A gcc issue ? Not sure what is expected from
those weak functions.

Ben.