Re: [PATCH v4 09/12] xen/spinlock: add missing rspin_is_locked() and rspin_barrier()

[Jürgen Groß <jgross@xxxxxxxx>]

On 29.02.24 15:14, Jan Beulich wrote:
> On 12.12.2023 10:47, Juergen Gross wrote:
> > --- a/xen/common/spinlock.c
> > +++ b/xen/common/spinlock.c
> > @@ -458,6 +458,23 @@ void _spin_barrier(spinlock_t *lock)
> >       spin_barrier_common(&lock->tickets, &lock->debug, LOCK_PROFILE_PAR);
> >   }
> >   
> > +int rspin_is_locked(const rspinlock_t *lock)
> > +{
> > +    /*
> > +     * Recursive locks may be locked by another CPU, yet we return
> > +     * "false" here, making this function suitable only for use in
> > +     * ASSERT()s and alike.
> > +     */
> > +    return lock->recurse_cpu == SPINLOCK_NO_CPU
> > +           ? spin_is_locked_common(&lock->tickets)
> > +           : lock->recurse_cpu == smp_processor_id();
> > +}
> > +
> > +void rspin_barrier(rspinlock_t *lock)
> > +{
> > +    spin_barrier_common(&lock->tickets, &lock->debug, LOCK_PROFILE_PAR);
> > +}
> Ah, here we go. Looks all okay to me, but needs re-ordering such that the
> earlier patch won't transiently introduce a regression.
Yes, just wanted to answer something similar to your remark on patch 8.


Juergen