Re: [GIT PULL] Please pull powerpc/linux.git powerpc-6.1-1 tag

["Nicholas Piggin" <npiggin@gmail.com>]

On Thu Oct 13, 2022 at 10:21 AM AEST, Guenter Roeck wrote:
> On Thu, Oct 13, 2022 at 11:03:34AM +1100, Michael Ellerman wrote:
> > Guenter Roeck <linux@roeck-us.net> writes:
> > > On Wed, Oct 12, 2022 at 11:20:38AM -0600, Jason A. Donenfeld wrote:
> > >> 
> > >> I've also managed to not hit this bug a few times. When it triggers,
> > >> after "kprobes: kprobe jump-optimization is enabled. All kprobes are
> > >> optimized if possible.", there's a long hang - tens seconds before it
> > >> continues. When it doesn't trigger, there's no hang at that point in the
> > >> boot process.
> > >> 
> > >
> > > I managed to bisect the problem. See below for results. Reverting the
> > > offending patch fixes the problem for me.
> > 
> > Thanks.
> > 
> > This is probably down to me/us not testing with PREEMPT enabled enough.
> > 
> Not sure. My configuration has
>
> CONFIG_PREEMPT_NONE=y
> # CONFIG_PREEMPT_VOLUNTARY is not set
> # CONFIG_PREEMPT is not set

Thanks very much for helping with this. The config snippet you posted here
https://lists.ozlabs.org/pipermail/linuxppc-dev/2022-October/249758.html
has CONFIG_PREEMPT=y. How do you turn that into a .config, olddefconfig?

I can't reproduce this so far using your config and qemu command line,
but the patch you've bisected it to definitely could cause this. I'll
keep trying...

Thanks,
Nick

[...]
> > > # first bad commit: [e485f6c751e0a969327336c635ca602feea117f0] powerpc/64/interrupt: Fix return to masked context after hard-mask irq becomes pending