svn commit: r325386 - head/sys/kern

[Konstantin Belousov]

On Sat, Nov 04, 2017 at 12:04:56PM -0700, Conrad Meyer wrote:
> This is a functional change, because MPASS (via KASSERT) is only
> enabled on DEBUG kernels.  Ideally we would have a kind of ASSERT that
> worked on NODEBUG kernels.
Why would we need such thing ?

Our conventions are clear: consistency checks are normally done with
KASSERT() and enabled for DEBUG (INVARIANTS or harder) configurations.
We only leave explicit panics in the production kernels when there
continuation of operations is worse then abort, e.g. when UFS detects
the metadata corruption.

The submission perfectly fits into this model.

> 
> Best,
> Conrad
> 
> On Sat, Nov 4, 2017 at 3:49 AM, Konstantin Belousov <kib at freebsd.org> wrote:
> > Author: kib
> > Date: Sat Nov  4 10:49:34 2017
> > New Revision: 325386
> > URL: https://svnweb.freebsd.org/changeset/base/325386
> >
> > Log:
> >   Convert explicit panic() call to assert.
> >
> >   Based on github pull request: #113
> >   Submitted by: pmarillo at github
> >   MFC after:    1 week
> >
> > Modified:
> >   head/sys/kern/kern_umtx.c
> >
> > Modified: head/sys/kern/kern_umtx.c
> > ==============================================================================
> > --- head/sys/kern/kern_umtx.c   Sat Nov  4 10:10:34 2017        (r325385)
> > +++ head/sys/kern/kern_umtx.c   Sat Nov  4 10:49:34 2017        (r325386)
> > @@ -1579,8 +1579,7 @@ umtx_pi_setowner(struct umtx_pi *pi, struct thread *ow
> >
> >         uq_owner = owner->td_umtxq;
> >         mtx_assert(&umtx_lock, MA_OWNED);
> > -       if (pi->pi_owner != NULL)
> > -               panic("pi_owner != NULL");
> > +       MPASS(pi->pi_owner == NULL);
> >         pi->pi_owner = owner;
> >         TAILQ_INSERT_TAIL(&uq_owner->uq_pi_contested, pi, pi_link);
> >  }
> >