1 files changed, 38 insertions, 25 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 437935e7a199..b19d759e55a5 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1327,6 +1327,9 @@ static void insert_work(struct pool_workqueue *pwq, struct work_struct *work,
 {
 	struct worker_pool *pool = pwq->pool;
 
+	/* record the work call stack in order to print it in KASAN reports */
+	kasan_record_aux_stack(work);
+
 	/* we own @work, set data and link */
 	set_work_pwq(work, pwq, extra_flags);
 	list_add_tail(&work->entry, head);
@@ -1409,7 +1412,6 @@ static void __queue_work(int cpu, struct workqueue_struct *wq,
 	 */
 	lockdep_assert_irqs_disabled();
 
-	debug_work_activate(work);
 
 	/* if draining, only works from the same workqueue are allowed */
 	if (unlikely(wq->flags & __WQ_DRAINING) &&
@@ -1491,6 +1493,7 @@ retry:
 		worklist = &pwq->delayed_works;
 	}
 
+	debug_work_activate(work);
 	insert_work(pwq, work, worklist, work_flags);
 
 out:
@@ -1627,7 +1630,7 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
 	struct work_struct *work = &dwork->work;
 
 	WARN_ON_ONCE(!wq);
-	WARN_ON_ONCE(timer->function != delayed_work_timer_fn);
+	WARN_ON_FUNCTION_MISMATCH(timer->function, delayed_work_timer_fn);
 	WARN_ON_ONCE(timer_pending(timer));
 	WARN_ON_ONCE(!list_empty(&work->entry));
 
@@ -1846,18 +1849,17 @@ static void worker_attach_to_pool(struct worker *worker,
 	mutex_lock(&wq_pool_attach_mutex);
 
 	/*
-	 * 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_cpus_allowed_ptr(worker->task, pool->attrs->cpumask);
-
-	/*
 	 * The wq_pool_attach_mutex ensures %POOL_DISASSOCIATED remains
 	 * stable across this function.  See the comments above the flag
 	 * definition for details.
 	 */
 	if (pool->flags & POOL_DISASSOCIATED)
 		worker->flags |= WORKER_UNBOUND;
+	else
+		kthread_set_per_cpu(worker->task, pool->cpu);
+
+	if (worker->rescue_wq)
+		set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask);
 
 	list_add_tail(&worker->node, &pool->workers);
 	worker->pool = pool;
@@ -1880,6 +1882,7 @@ static void worker_detach_from_pool(struct worker *worker)
 
 	mutex_lock(&wq_pool_attach_mutex);
 
+	kthread_set_per_cpu(worker->task, -1);
 	list_del(&worker->node);
 	worker->pool = NULL;
 
@@ -2961,8 +2964,8 @@ reflush:
 
 		if (++flush_cnt == 10 ||
 		    (flush_cnt % 100 == 0 && flush_cnt <= 1000))
-			pr_warn("workqueue %s: drain_workqueue() isn't complete after %u tries\n",
-				wq->name, flush_cnt);
+			pr_warn("workqueue %s: %s() isn't complete after %u tries\n",
+				wq->name, __func__, flush_cnt);
 
 		mutex_unlock(&wq->mutex);
 		goto reflush;
@@ -3728,17 +3731,24 @@ static void pwq_adjust_max_active(struct pool_workqueue *pwq)
 	 * is updated and visible.
 	 */
 	if (!freezable || !workqueue_freezing) {
+		bool kick = false;
+
 		pwq->max_active = wq->saved_max_active;
 
 		while (!list_empty(&pwq->delayed_works) &&
-		       pwq->nr_active < pwq->max_active)
+		       pwq->nr_active < pwq->max_active) {
 			pwq_activate_first_delayed(pwq);
+			kick = true;
+		}
 
 		/*
 		 * Need to kick a worker after thawed or an unbound wq's
-		 * max_active is bumped.  It's a slow path.  Do it always.
+		 * max_active is bumped. In realtime scenarios, always kicking a
+		 * worker will cause interference on the isolated cpu cores, so
+		 * let's kick iff work items were activated.
 		 */
-		wake_up_worker(pwq->pool);
+		if (kick)
+			wake_up_worker(pwq->pool);
 	} else {
 		pwq->max_active = 0;
 	}
@@ -4908,6 +4918,12 @@ static void unbind_workers(int cpu)
 		pool->flags |= POOL_DISASSOCIATED;
 
 		raw_spin_unlock_irq(&pool->lock);
+
+		for_each_pool_worker(worker, pool) {
+			kthread_set_per_cpu(worker->task, -1);
+			WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, cpu_possible_mask) < 0);
+		}
+
 		mutex_unlock(&wq_pool_attach_mutex);
 
 		/*
@@ -4958,9 +4974,11 @@ static void rebind_workers(struct worker_pool *pool)
 	 * of all workers first and then clear UNBOUND.  As we're called
 	 * from CPU_ONLINE, the following shouldn't fail.
 	 */
-	for_each_pool_worker(worker, pool)
+	for_each_pool_worker(worker, pool) {
+		kthread_set_per_cpu(worker->task, pool->cpu);
 		WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task,
 						  pool->attrs->cpumask) < 0);
+	}
 
 	raw_spin_lock_irq(&pool->lock);
 
@@ -5769,22 +5787,17 @@ static void wq_watchdog_timer_fn(struct timer_list *unused)
 			continue;
 
 		/* get the latest of pool and touched timestamps */
+		if (pool->cpu >= 0)
+			touched = READ_ONCE(per_cpu(wq_watchdog_touched_cpu, pool->cpu));
+		else
+			touched = READ_ONCE(wq_watchdog_touched);
 		pool_ts = READ_ONCE(pool->watchdog_ts);
-		touched = READ_ONCE(wq_watchdog_touched);
 
 		if (time_after(pool_ts, touched))
 			ts = pool_ts;
 		else
 			ts = touched;
 
-		if (pool->cpu >= 0) {
-			unsigned long cpu_touched =
-				READ_ONCE(per_cpu(wq_watchdog_touched_cpu,
-						  pool->cpu));
-			if (time_after(cpu_touched, ts))
-				ts = cpu_touched;
-		}
-
 		/* did we stall? */
 		if (time_after(jiffies, ts + thresh)) {
 			lockup_detected = true;
@@ -5808,8 +5821,8 @@ notrace void wq_watchdog_touch(int cpu)
 {
 	if (cpu >= 0)
 		per_cpu(wq_watchdog_touched_cpu, cpu) = jiffies;
-	else
-		wq_watchdog_touched = jiffies;
+
+	wq_watchdog_touched = jiffies;
 }
 
 static void wq_watchdog_set_thresh(unsigned long thresh)