Re: [PATCH 10/11] x86, rwsem: provide __down_write_killable

Peter Zijlstra
2016-04-20T13:40:19Z

On Wed, Apr 13, 2016 at 02:49:43PM +0200, Michal Hocko wrote:
> On Wed 13-04-16 12:27:31, Ingo Molnar wrote:
> >
> > * Ingo Molnar <mingo@kernel.org> wrote:
> >
> > > I'm testing your patches today, if they are otherwise OK [...]
> >
> > got this build failure:
> >
> > ./arch/x86/include/asm/rwsem.h:106:2: error: ‘asm’ operand has impossible constraints
>
> Hmm, I have no idea why 64b didn't have problem with the asm but 32b
> complains. Anyway, the following makes both happy. I have checked the
> generated code for 64b and it hasn't changed after the patch. 32b also
> seems to be generating a proper code. My gcc asm()-foo is rather weak so
> I would feel better if somebody double checked after me.

I completely blow at this gcc-asm constraints thing too :/

In any case, Ingo will you look after the rest of these patches, or do
you want me to pick up the remaining bits?