Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...

[linux-drm-fsl-dcu.git] / kernel / workqueue.c

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 987293d03ebcf0e6bf1c6b81e8a4e68c7965e903..c66912be990fbda0f61e7a58fdbc52cf304566c2 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -305,6 +305,9 @@ static DEFINE_HASHTABLE(unbound_pool_hash, UNBOUND_POOL_HASH_ORDER);
 /* I: attributes used when instantiating standard unbound pools on demand */
 static struct workqueue_attrs *unbound_std_wq_attrs[NR_STD_WORKER_POOLS];
 
+/* I: attributes used when instantiating ordered pools on demand */
+static struct workqueue_attrs *ordered_wq_attrs[NR_STD_WORKER_POOLS];
+
 struct workqueue_struct *system_wq __read_mostly;
 EXPORT_SYMBOL(system_wq);
 struct workqueue_struct *system_highpri_wq __read_mostly;
@@ -518,14 +521,21 @@ static inline void debug_work_activate(struct work_struct *work) { }
 static inline void debug_work_deactivate(struct work_struct *work) { }
 #endif
 
-/* allocate ID and assign it to @pool */
+/**
+ * worker_pool_assign_id - allocate ID and assing it to @pool
+ * @pool: the pool pointer of interest
+ *
+ * Returns 0 if ID in [0, WORK_OFFQ_POOL_NONE) is allocated and assigned
+ * successfully, -errno on failure.
+ */
 static int worker_pool_assign_id(struct worker_pool *pool)
 {
        int ret;
 
        lockdep_assert_held(&wq_pool_mutex);
 
-       ret = idr_alloc(&worker_pool_idr, pool, 0, 0, GFP_KERNEL);
+       ret = idr_alloc(&worker_pool_idr, pool, 0, WORK_OFFQ_POOL_NONE,
+                       GFP_KERNEL);
        if (ret >= 0) {
                pool->id = ret;
                return 0;
@@ -1320,7 +1330,7 @@ static void __queue_work(int cpu, struct workqueue_struct *wq,
 
        debug_work_activate(work);
 
-       /* if dying, only works from the same workqueue are allowed */
+       /* if draining, only works from the same workqueue are allowed */
        if (unlikely(wq->flags & __WQ_DRAINING) &&
            WARN_ON_ONCE(!is_chained_work(wq)))
                return;
@@ -1736,16 +1746,17 @@ static struct worker *create_worker(struct worker_pool *pool)
        if (IS_ERR(worker->task))
                goto fail;
 
+       set_user_nice(worker->task, pool->attrs->nice);
+
+       /* prevent userland from meddling with cpumask of workqueue workers */
+       worker->task->flags |= PF_NO_SETAFFINITY;
+
        /*
         * set_cpus_allowed_ptr() will fail if the cpumask doesn't have any
         * online CPUs.  It'll be re-applied when any of the CPUs come up.
         */
-       set_user_nice(worker->task, pool->attrs->nice);
        set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask);
 
-       /* prevent userland from meddling with cpumask of workqueue workers */
-       worker->task->flags |= PF_NO_SETAFFINITY;
-
        /*
         * The caller is responsible for ensuring %POOL_DISASSOCIATED
         * remains stable across this function.  See the comments above the
@@ -4106,7 +4117,7 @@ out_unlock:
 static int alloc_and_link_pwqs(struct workqueue_struct *wq)
 {
        bool highpri = wq->flags & WQ_HIGHPRI;
-       int cpu;
+       int cpu, ret;
 
        if (!(wq->flags & WQ_UNBOUND)) {
                wq->cpu_pwqs = alloc_percpu(struct pool_workqueue);
@@ -4126,6 +4137,13 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq)
                        mutex_unlock(&wq->mutex);
                }
                return 0;
+       } else if (wq->flags & __WQ_ORDERED) {
+               ret = apply_workqueue_attrs(wq, ordered_wq_attrs[highpri]);
+               /* there should only be single pwq for ordering guarantee */
+               WARN(!ret && (wq->pwqs.next != &wq->dfl_pwq->pwqs_node ||
+                             wq->pwqs.prev != &wq->dfl_pwq->pwqs_node),
+                    "ordering guarantee broken for workqueue %s\n", wq->name);
+               return ret;
        } else {
                return apply_workqueue_attrs(wq, unbound_std_wq_attrs[highpri]);
        }
@@ -5009,10 +5027,6 @@ static int __init init_workqueues(void)
        int std_nice[NR_STD_WORKER_POOLS] = { 0, HIGHPRI_NICE_LEVEL };
        int i, cpu;
 
-       /* make sure we have enough bits for OFFQ pool ID */
-       BUILD_BUG_ON((1LU << (BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT)) <
-                    WORK_CPU_END * NR_STD_WORKER_POOLS);
-
        WARN_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
 
        pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);
@@ -5051,13 +5065,23 @@ static int __init init_workqueues(void)
                }
        }
 
-       /* create default unbound wq attrs */
+       /* create default unbound and ordered wq attrs */
        for (i = 0; i < NR_STD_WORKER_POOLS; i++) {
                struct workqueue_attrs *attrs;
 
                BUG_ON(!(attrs = alloc_workqueue_attrs(GFP_KERNEL)));
                attrs->nice = std_nice[i];
                unbound_std_wq_attrs[i] = attrs;
+
+               /*
+                * An ordered wq should have only one pwq as ordering is
+                * guaranteed by max_active which is enforced by pwqs.
+                * Turn off NUMA so that dfl_pwq is used for all nodes.
+                */
+               BUG_ON(!(attrs = alloc_workqueue_attrs(GFP_KERNEL)));
+               attrs->nice = std_nice[i];
+               attrs->no_numa = true;
+               ordered_wq_attrs[i] = attrs;
        }
 
        system_wq = alloc_workqueue("events", 0, 0);