[PATCH] workqueue: get the probable node ID from the first CPU of the mask

[Lai Jiangshan <laijs@cn.fujitsu.com>]

Current get_unbound_pool() considers all node IDs are probable for
the pool, and it travel all nodes to find the node ID for the pool.
This travel is unnecessary, the probable node ID can be attained
from the first CPU and we need check only one possible node ID.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
 kernel/workqueue.c |   10 ++++------
 1 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 347ac5b..942103d9 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3482,12 +3482,10 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
 
 	/* if cpumask is contained inside a NUMA node, we belong to that node */
 	if (wq_numa_enabled) {
-		for_each_node(node) {
-			if (cpumask_subset(pool->attrs->cpumask,
-					   wq_numa_possible_cpumask[node])) {
-				pool->node = node;
-				break;
-			}
+		node = cpu_to_node(cpumask_first(pool->attrs->cpumask));
+		if (cpumask_subset(pool->attrs->cpumask,
+				   wq_numa_possible_cpumask[node])) {
+			pool->node = node;
 		}
 	}
 
-- 
1.7.4.4