Re: [PATCH v2 03/45] notifier: Add atomic/blocking_notifier_has_unique_priority()
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2021-10-28 11:01:15
Also in:
linux-acpi, linux-m68k, linux-mips, linux-omap, linux-pm, linux-riscv, linux-tegra, linuxppc-dev, lkml, xen-devel
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