Re: [patch V3 15/64] rtmutex: Provide rt_mutex_base_is_locked()

[Thomas Gleixner]

On Sun, Aug 08 2021 at 13:41, Davidlohr Bueso wrote:
>>+/**
>>+ * rt_mutex_base_is_locked - is the rtmutex locked
>>+ * @lock: the mutex to be queried
>>+ *
>>+ * Returns true if the mutex is locked, false if unlocked.
>>+ */
>>+static inline bool rt_mutex_base_is_locked(struct rt_mutex_base *lock)
>>+{
>>+	return lock->owner != NULL;
>
> Does this want to be READ_ONCE()? While not a big deal because
> it's ultimately only used by drm debugging, I don't see any harm
> in avoiding potential tearing.

Makes sense.