Re: [Qemu-devel] RFC: fix for random Qemu crashes

["J. Mayer" <l_indien@magic.fr>]

On Fri, 2007-11-16 at 21:32 +0100, andrzej zaborowski wrote:
> On 16/11/2007, Jocelyn Mayer <l_indien@magic.fr> wrote:
> >
> > On Fri, 2007-11-16 at 15:52 +0000, Paul Brook wrote:
> > > > Then, I choosed to replace 'inline' by 'always_inline', which is more
> > > > invasive but have less risks of side effects. The diff is attached in
> > > > always_inline.diff.
> > > > The last thing that helps solve the problem is to change the inlining
> > > > limits of gcc, at least to compile the op.o file.
> > >
> > > Presumably we only need one of the last two patches? It seems rather pointless
> > > to have always_inline *and* change the inlining heuristics.
> >
> > >From the tests I made, it seems that adding always_inline helps but
> > unfortunatelly does not solve all cases. Should check in the gcc source
> > code why it is so...
> >
> > > I'm ok with using always_inline for op.o (and things it uses directly) as this
> > > is required for correctness. I'm not convinced that that using always_inline
> > > everywhere is such a good idea.
> >
> > That's exactly what I did: I changed 'inline' to 'always_inline' in
> > headers that are included by op.c, I did not made any change in other
> > headers.
> 
> I think a line like
> 
> #define inline __attribute__ (( always_inline )) inline
> 
> in dyngen-exec.h should be 

As I already pointed it in the first message of the thread, this kind of
define would expand recursivelly, which is particullary ugly, and which
can in some cases lead to compiler warnings or errors. I already had
this kind of problems using the linux kernel headers which preciselly
uses this definitition.
But, once again, adding always_inline to functions does not completelly
solve the problem (please read the thread !) or at least does not solves
it with all gcc versions. The inline growth limits tweaking seems needed
too.

-- 
J. Mayer <l_indien@magic.fr>
Never organized