Re: de8f5e4f2d ("lockdep: Introduce wait-type checks"): [ 17.344674] EIP: default_idle

From: Sebastian Andrzej Siewior
Date: Thu Apr 02 2020 - 05:58:20 EST


On 2020-04-02 11:40:52 [+0200], Thomas Gleixner wrote:
> kernel test robot <lkp@xxxxxxxxx> writes:
> > Greetings,
> >
> > 0day kernel testing robot got the below dmesg and the first bad commit is
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> >
> > commit de8f5e4f2dc1f032b46afda0a78cab5456974f89
> > Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > AuthorDate: Sat Mar 21 12:26:01 2020 +0100
> > Commit: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > CommitDate: Sat Mar 21 16:00:24 2020 +0100
> >
> > lockdep: Introduce wait-type checks
>
> Can you please avoid enabling
>
> > CONFIG_PROVE_RAW_LOCK_NESTING=y
>
> for now?
>
> As the changelog states, there are known issues and that's why the
> config is default=n.

There is that. What puzzled me for a little while was the part that the
call chain itself is *valid* and should not trigger this. After staring
at it for a while I noticed that the test was performed *before* the
hrtimer bits were merged.

> Thanks,
>
> tglx

Sebastian