workqueue: copy workqueue_attrs with all fields

 $echo '0' > /sys/bus/workqueue/devices/xxx/numa
 $cat /sys/bus/workqueue/devices/xxx/numa

I got 1. It should be 0, the reason is copy_workqueue_attrs() called
in apply_workqueue_attrs() doesn't copy no_numa field.

Fix it by making copy_workqueue_attrs() copy ->no_numa too.  This
would also make get_unbound_pool() set a pool's ->no_numa attribute
according to the workqueue attributes used when the pool was created.
While harmelss, as ->no_numa isn't a pool attribute, this is a bit
confusing.  Clear it explicitly.

tj: Updated description and comments a bit.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 55f5f0afcd0d966f137293c262c1621b3ebda730..726adc84b3ca6b3e413ab1eb1af4e528a359e0ff 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3416,6 +3416,12 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to,
 {
        to->nice = from->nice;
        cpumask_copy(to->cpumask, from->cpumask);
+       /*
+        * Unlike hash and equality test, this function doesn't ignore
+        * ->no_numa as it is used for both pool and wq attrs.  Instead,
+        * get_unbound_pool() explicitly clears ->no_numa after copying.
+        */
+       to->no_numa = from->no_numa;
 }
 
 /* hash value of the content of @attr */
@@ -3583,6 +3589,12 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
        lockdep_set_subclass(&pool->lock, 1);   /* see put_pwq() */
        copy_workqueue_attrs(pool->attrs, attrs);
 
+       /*
+        * no_numa isn't a worker_pool attribute, always clear it.  See
+        * 'struct workqueue_attrs' comments for detail.
+        */
+       pool->attrs->no_numa = false;
+
        /* if cpumask is contained inside a NUMA node, we belong to that node */
        if (wq_numa_enabled) {
                for_each_node(node) {