amd64 head -r329465 (non-debug build, but with symbols): "panic: spin lock held too long" during make check-old, reported during a sys_vfork

[Mateusz Guzik]

On Sun, Feb 18, 2018 at 11:24 PM, Trond Endrestøl <
Trond.Endrestol at fagskolen.gjovik.no> wrote:

> On Sun, 18 Feb 2018 22:33+0100, Mateusz Guzik wrote:
>
> > On Sun, Feb 18, 2018 at 9:38 PM, Trond Endrestøl <
> > Trond.Endrestol at fagskolen.gjovik.no> wrote:
> >
> > > On Sun, 18 Feb 2018 11:51-0800, Mark Millard wrote:
> > >
> > > > Note: -r329448 was reverted in -r329461 : racy.
> > >
> > > True. I got a crash when compiling r329451 while running r329449.
> > > I've now booted the r329422 ZFS BE and I'm attempting to build
> > > r329529.
> > >
> >
> > Looking around strongly suggests r329448 is the culprit. If you can
> verify
> > 329447 works fine we are mostly done here.
>
> I noticed no errors in r329447. When r329529 is built and installed,
> I'll try to incrementally build and install r329531.
>

Can you grab a panicking kernel and apply this:
https://people.freebsd.org/~mjg/wait_unlocked.diff

there may be debug printfs signifying the problem condition was hit,
however the patch should fix the panic

-- 
Mateusz Guzik <mjguzik gmail.com>