Re: [patch] futex: Fix v4.6+ ltp futex_wait04 regression

Mel Gorman
2016-06-07T11:20:59Z

On Tue, Jun 07, 2016 at 11:50:56AM +0100, Mel Gorman wrote:
> On Mon, Jun 06, 2016 at 11:40:41AM +0200, Mike Galbraith wrote:
> > Hi Mel (who is out of the office today),
> >
>
> Adding Davidlohr who did a lot of the work debugging my initial
> prototype.
>
> > I initially reported this on the rt-users list, thinking at the time
> > that it was only showing up in -rt kernels, but that turned out to not
> > be the case, it just requires an enterprise config for some reason mm
> > folks will likely recognize instantly. I just happen to use same when
> > building devel -rt trees to at least get some build warning coverage.
> >
>
> Can you post the exact config? I used an enterprise config and was unable
> to reproduce the problem on 4.6. I'll be trying 4.7-rc1 after finishing
> this mail even though the optimisation was introduced before 4.6.
>

Never mind, I reproduced the problem and reckon I know where the problem
is. I'll keep poking at it.

--
Mel Gorman
SUSE Labs