Merge remote-tracking branch 'tip/x86/cpufeature' into kvm-next

1 files changed, 37 insertions, 13 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 987293d03ebc..c66912be990f 100644
--- 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);