Re: [PATCH v2 03/45] notifier: Add atomic/blocking_notifier_has_unique_priority()

Andy Shevchenko
2021-10-28T11:00:31Z

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