On Thu, Oct 28, 2021 at 12:16:33AM +0300, Dmitry Osipenko wrote:
Add atomic/blocking_notifier_has_unique_priority() helpers which return
true if given handler has unique priority.
...
+/**
+ * atomic_notifier_has_unique_priority - Checks whether notifier's priority is unique
+ * @nh: Pointer to head of the atomic notifier chain
+ * @n: Entry in notifier chain to check
+ *
+ * Checks whether there is another notifier in the chain with the same priority.
+ * Must be called in process context.
+ *
+ * Returns true if priority is unique, false otherwise.
Why this indentation?
+ */
+bool atomic_notifier_has_unique_priority(struct atomic_notifier_head *nh,
+ struct notifier_block *n)
+{
+ struct notifier_block **nl = &nh->head;
+ unsigned long flags;
+ bool ret = true;
+
+ spin_lock_irqsave(&nh->lock, flags);
+
+ while ((*nl) != NULL && (*nl)->priority >= n->priority) {
' != NULL' is redundant.
+ if ((*nl)->priority == n->priority && (*nl) != n) {
+ ret = false;
+ break;
+ }
+
+ nl = &((*nl)->next);
+ }
+
+ spin_unlock_irqrestore(&nh->lock, flags);
+
+ return ret;
+}
...
+ /*
+ * This code gets used during boot-up, when task switching is
+ * not yet working and interrupts must remain disabled. At
One space is enough.
+ * such times we must not call down_write().
+ */
+ while ((*nl) != NULL && (*nl)->priority >= n->priority) {
' != NULL' is not needed.
+ if ((*nl)->priority == n->priority && (*nl) != n) {
+ ret = false;
+ break;
+ }
+
+ nl = &((*nl)->next);
+ }
--
With Best Regards,
Andy Shevchenko
