[PATCH 4/6] genirq: optimize irq_do_set_affinity()

[Yury Norov]

If mask == desc->irq_common_data.affinity, copying one to another is
useless, and we can just skip it.

Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
---
 kernel/irq/manage.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index bf9ae8a8686f..ad9ed9fdf919 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -285,7 +285,8 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
 	switch (ret) {
 	case IRQ_SET_MASK_OK:
 	case IRQ_SET_MASK_OK_DONE:
-		cpumask_copy(desc->irq_common_data.affinity, mask);
+		if (desc->irq_common_data.affinity != mask)
+			cpumask_copy(desc->irq_common_data.affinity, mask);
 		fallthrough;
 	case IRQ_SET_MASK_OK_NOCOPY:
 		irq_validate_effective_affinity(data);
-- 
2.40.1