genirq: Update affinity of secondary threads

For interrupts with secondary threads, the affinity is applied when the
thread is created but if the interrupts affinity is changed later only
the primary thread is updated.

Update the secondary thread's affinity as well to keep all the interrupts
activity on the assigned CPUs.

Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230406180857.588682-1-john@metanate.com

Author: johnkeeping

kernel/irq/manage.c

@@ -189,9 +189,12 @@ void irq_set_thread_affinity(struct irq_desc *desc)
 {
 	struct irqaction *action;
 
-	for_each_action_of_desc(desc, action)
+	for_each_action_of_desc(desc, action) {
 		if (action->thread)
 			set_bit(IRQTF_AFFINITY, &action->thread_flags);
+		if (action->secondary && action->secondary->thread)
+			set_bit(IRQTF_AFFINITY, &action->secondary->thread_flags);
+	}
 }
 
 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK