Re: [UML] 3.16 build without optimization fails

From: Thomas Meyer
Date: Tue Aug 19 2014 - 16:35:26 EST


Yes, it's still there.

Am 19.08.2014 22:26 schrieb Richard Weinberger <richard.weinberger@xxxxxxxxx>:
>
> On Tue, Aug 19, 2014 at 10:19 PM, Thomas Meyer <thomas@xxxxxxxx> wrote:
> > Hi.
> >
> > Thanks for your answer.
> >
> > There goes my plan to better understand an UML kernel lock up by using a debugger... Everything gets optimised out with -O2 :-(
>
> Is it the filesystem/block lockup you saw some time ago?
> Maybe Thorsten can give more details.
> He sent me an patch off list a few days ago.
>
> > Can you give an example function that relies on this GCC feature?
> >
> > With kind regards
> > Thomas
> >
> > Am 19.08.2014 22:06 schrieb Valdis.Kletnieks@xxxxxx:
> >>
> >> On Tue, 19 Aug 2014 21:12:10 +0200, Thomas Meyer said:
> >> > > Hi,
> >> > >
> >> > > the build with -O0 fails with:
> >>
> >> > > bug or feature?
> >> > >
> >> > > any ideas?
> >>
> >> Feature. The kernel is *known* to not build with -O0, because that
> >> disables *all* function inlining, and there's several functions that *have*
> >> to be inlined in order to function properly (most notably, anything
> >> that uses the gcc __builtin_return_address in a function that is expected
> >> to be inlined).
>
>
>
> --
> Thanks,
> //richard