On Mon, Sep 26, 2016 at 11:20:58AM -0400, Steven Rostedt wrote:
> > --- a/kernel/locking/rtmutex.c
> > +++ b/kernel/locking/rtmutex.c
> > @@ -256,6 +256,16 @@ rt_mutex_dequeue_pi(struct task_struct *
> > RB_CLEAR_NODE(&waiter->pi_tree_entry);
> > }
> >
>
> Shouldn't we add a comment about what locks are expected to be held
> when calling this? Especially if it can be called outside this file.
Comments are somewhat useless.. I would like to do the below, except I
cannot.
> > +void rt_mutex_update_top_task(struct task_struct *p)
> > +{
lockdep_assert_held(&p->pi_lock);
lockdep_assert_held(&task_rq(p)->lock); // except that we cannot access
rq :/
> > + if (!task_has_pi_waiters(p)) {
> > + p->pi_top_task = NULL;
> > + return;
> > + }
> > +
> > + p->pi_top_task = task_top_pi_waiter(p)->task;
> > +}
> > +
> > /*
> > * Calculate task priority from the waiter tree priority
> > *
> > @@ -273,10 +283,7 @@ int rt_mutex_getprio(struct task_struct
> >
>
> Any specific locks that must be held when calling this?
#ifdef CONFIG_LOCKDEP
WARN_ON_ONCE(debug_locks &&
!lock_is_held(&p->pi_lock) &&
!lock_is_held(&task_rq(p)->lock)); // again, cannot do this :/
#endif
> > struct task_struct *rt_mutex_get_top_task(struct task_struct *task)
> > {
> > - if (likely(!task_has_pi_waiters(task)))
> > - return NULL;
> > -
> > - return task_top_pi_waiter(task)->task;
> > + return task->pi_top_task;
> > }
>
> -- Steve
>
