genirq/affinity: replace cpumask_weight with cpumask_empty where appropriate

__irq_build_affinity_masks() calls cpumask_weight() to check if
any bit of a given cpumask is set. We can do it more efficiently with
cpumask_empty() because cpumask_empty() stops traversing the cpumask as
soon as it finds first set bit, while cpumask_weight() counts all bits
unconditionally.

Signed-off-by: Yury Norov <yury.norov@gmail.com>

diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index f7ff891..18740fa 100644 (file)
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -258,7 +258,7 @@ static int __irq_build_affinity_masks(unsigned int startvec,
        nodemask_t nodemsk = NODE_MASK_NONE;
        struct node_vectors *node_vectors;
 
-       if (!cpumask_weight(cpu_mask))
+       if (cpumask_empty(cpu_mask))
                return 0;
 
        nodes = get_nodes_in_cpumask(node_to_cpumask, cpu_mask, &nodemsk);