Merge tag 'drm-misc-fixes-2017-08-08' of git://anongit.freedesktop.org/git/drm-misc...

[karo-tx-linux.git] / kernel / workqueue.c

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index a86688fabc55c4a4ec2bad843f6dc1e0e411f2d1..ca937b0c3a968f247a227d68812c9062fb4916c5 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3577,6 +3577,13 @@ static bool wq_calc_node_cpumask(const struct workqueue_attrs *attrs, int node,
 
        /* yeap, return possible CPUs in @node that @attrs wants */
        cpumask_and(cpumask, attrs->cpumask, wq_numa_possible_cpumask[node]);
+
+       if (cpumask_empty(cpumask)) {
+               pr_warn_once("WARNING: workqueue cpumask: online intersect > "
+                               "possible intersect\n");
+               return false;
+       }
+
        return !cpumask_equal(cpumask, attrs->cpumask);
 
 use_dfl:
@@ -3744,8 +3751,12 @@ static int apply_workqueue_attrs_locked(struct workqueue_struct *wq,
                return -EINVAL;
 
        /* creating multiple pwqs breaks ordering guarantee */
-       if (WARN_ON((wq->flags & __WQ_ORDERED) && !list_empty(&wq->pwqs)))
-               return -EINVAL;
+       if (!list_empty(&wq->pwqs)) {
+               if (WARN_ON(wq->flags & __WQ_ORDERED_EXPLICIT))
+                       return -EINVAL;
+
+               wq->flags &= ~__WQ_ORDERED;
+       }
 
        ctx = apply_wqattrs_prepare(wq, attrs);
        if (!ctx)
@@ -3929,6 +3940,16 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt,
        struct workqueue_struct *wq;
        struct pool_workqueue *pwq;
 
+       /*
+        * Unbound && max_active == 1 used to imply ordered, which is no
+        * longer the case on NUMA machines due to per-node pools.  While
+        * alloc_ordered_workqueue() is the right way to create an ordered
+        * workqueue, keep the previous behavior to avoid subtle breakages
+        * on NUMA.
+        */
+       if ((flags & WQ_UNBOUND) && max_active == 1)
+               flags |= __WQ_ORDERED;
+
        /* see the comment above the definition of WQ_POWER_EFFICIENT */
        if ((flags & WQ_POWER_EFFICIENT) && wq_power_efficient)
                flags |= WQ_UNBOUND;
@@ -4119,13 +4140,14 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active)
        struct pool_workqueue *pwq;
 
        /* disallow meddling with max_active for ordered workqueues */
-       if (WARN_ON(wq->flags & __WQ_ORDERED))
+       if (WARN_ON(wq->flags & __WQ_ORDERED_EXPLICIT))
                return;
 
        max_active = wq_clamp_max_active(max_active, wq->flags, wq->name);
 
        mutex_lock(&wq->mutex);
 
+       wq->flags &= ~__WQ_ORDERED;
        wq->saved_max_active = max_active;
 
        for_each_pwq(pwq, wq)
@@ -5253,7 +5275,7 @@ int workqueue_sysfs_register(struct workqueue_struct *wq)
         * attributes breaks ordering guarantee.  Disallow exposing ordered
         * workqueues.
         */
-       if (WARN_ON(wq->flags & __WQ_ORDERED))
+       if (WARN_ON(wq->flags & __WQ_ORDERED_EXPLICIT))
                return -EINVAL;
 
        wq->wq_dev = wq_dev = kzalloc(sizeof(*wq_dev), GFP_KERNEL);