Merge branch 'next' into for-linus

Prepare input updates for 7.1 merge window.

1 files changed, 200 insertions, 101 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 45320e27a16c..b77119d71641 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -117,6 +117,8 @@ enum wq_internal_consts {
 	MAYDAY_INTERVAL		= HZ / 10,	/* and then every 100ms */
 	CREATE_COOLDOWN		= HZ,		/* time to breath after fail */
 
+	RESCUER_BATCH		= 16,		/* process items per turn */
+
 	/*
 	 * Rescue workers are used only on emergencies and shared by
 	 * all cpus.  Give MIN_NICE.
@@ -188,7 +190,7 @@ struct worker_pool {
 	int			id;		/* I: pool ID */
 	unsigned int		flags;		/* L: flags */
 
-	unsigned long		watchdog_ts;	/* L: watchdog timestamp */
+	unsigned long		last_progress_ts;	/* L: last forward progress timestamp */
 	bool			cpu_stall;	/* WD: stalled cpu bound pool */
 
 	/*
@@ -286,6 +288,7 @@ struct pool_workqueue {
 	struct list_head	pending_node;	/* LN: node on wq_node_nr_active->pending_pwqs */
 	struct list_head	pwqs_node;	/* WR: node on wq->pwqs */
 	struct list_head	mayday_node;	/* MD: node on wq->maydays */
+	struct work_struct	mayday_cursor;	/* L: cursor on pool->worklist */
 
 	u64			stats[PWQ_NR_STATS];
 
@@ -541,12 +544,6 @@ static void show_one_worker_pool(struct worker_pool *pool);
 			 !lockdep_is_held(&wq_pool_mutex),		\
 			 "RCU or wq_pool_mutex should be held")
 
-#define assert_rcu_or_wq_mutex_or_pool_mutex(wq)			\
-	RCU_LOCKDEP_WARN(!rcu_read_lock_any_held() &&			\
-			 !lockdep_is_held(&wq->mutex) &&		\
-			 !lockdep_is_held(&wq_pool_mutex),		\
-			 "RCU, wq->mutex or wq_pool_mutex should be held")
-
 #define for_each_bh_worker_pool(pool, cpu)				\
 	for ((pool) = &per_cpu(bh_worker_pools, cpu)[0];		\
 	     (pool) < &per_cpu(bh_worker_pools, cpu)[NR_STD_WORKER_POOLS]; \
@@ -1126,6 +1123,12 @@ static struct worker *find_worker_executing_work(struct worker_pool *pool,
 	return NULL;
 }
 
+static void mayday_cursor_func(struct work_struct *work)
+{
+	/* should not be processed, only for marking position */
+	BUG();
+}
+
 /**
  * move_linked_works - move linked works to a list
  * @work: start of series of works to be scheduled
@@ -1188,6 +1191,16 @@ static bool assign_work(struct work_struct *work, struct worker *worker,
 
 	lockdep_assert_held(&pool->lock);
 
+	/* The cursor work should not be processed */
+	if (unlikely(work->func == mayday_cursor_func)) {
+		/* only worker_thread() can possibly take this branch */
+		WARN_ON_ONCE(worker->rescue_wq);
+		if (nextp)
+			*nextp = list_next_entry(work, entry);
+		list_del_init(&work->entry);
+		return false;
+	}
+
 	/*
 	 * A single work shouldn't be executed concurrently by multiple workers.
 	 * __queue_work() ensures that @work doesn't jump to a different pool
@@ -1684,7 +1697,7 @@ static void __pwq_activate_work(struct pool_workqueue *pwq,
 	WARN_ON_ONCE(!(*wdb & WORK_STRUCT_INACTIVE));
 	trace_workqueue_activate_work(work);
 	if (list_empty(&pwq->pool->worklist))
-		pwq->pool->watchdog_ts = jiffies;
+		pwq->pool->last_progress_ts = jiffies;
 	move_linked_works(work, &pwq->pool->worklist, NULL);
 	__clear_bit(WORK_STRUCT_INACTIVE_BIT, wdb);
 }
@@ -2335,7 +2348,7 @@ retry:
 	 */
 	if (list_empty(&pwq->inactive_works) && pwq_tryinc_nr_active(pwq, false)) {
 		if (list_empty(&pool->worklist))
-			pool->watchdog_ts = jiffies;
+			pool->last_progress_ts = jiffies;
 
 		trace_workqueue_activate_work(work);
 		insert_work(pwq, work, &pool->worklist, work_flags);
@@ -2982,9 +2995,8 @@ static void idle_cull_fn(struct work_struct *work)
 	reap_dying_workers(&cull_list);
 }
 
-static void send_mayday(struct work_struct *work)
+static void send_mayday(struct pool_workqueue *pwq)
 {
-	struct pool_workqueue *pwq = get_work_pwq(work);
 	struct workqueue_struct *wq = pwq->wq;
 
 	lockdep_assert_held(&wq_mayday_lock);
@@ -3022,7 +3034,7 @@ static void pool_mayday_timeout(struct timer_list *t)
 		 * rescuers.
 		 */
 		list_for_each_entry(work, &pool->worklist, entry)
-			send_mayday(work);
+			send_mayday(get_work_pwq(work));
 	}
 
 	raw_spin_unlock(&wq_mayday_lock);
@@ -3192,6 +3204,7 @@ __acquires(&pool->lock)
 	worker->current_pwq = pwq;
 	if (worker->task)
 		worker->current_at = worker->task->se.sum_exec_runtime;
+	worker->current_start = jiffies;
 	work_data = *work_data_bits(work);
 	worker->current_color = get_work_color(work_data);
 
@@ -3340,7 +3353,7 @@ static void process_scheduled_works(struct worker *worker)
 	while ((work = list_first_entry_or_null(&worker->scheduled,
 						struct work_struct, entry))) {
 		if (first) {
-			worker->pool->watchdog_ts = jiffies;
+			worker->pool->last_progress_ts = jiffies;
 			first = false;
 		}
 		process_one_work(worker, work);
@@ -3443,6 +3456,62 @@ sleep:
 	goto woke_up;
 }
 
+static bool assign_rescuer_work(struct pool_workqueue *pwq, struct worker *rescuer)
+{
+	struct worker_pool *pool = pwq->pool;
+	struct work_struct *cursor = &pwq->mayday_cursor;
+	struct work_struct *work, *n;
+
+	/* have work items to rescue? */
+	if (!pwq->nr_active)
+		return false;
+
+	/* need rescue? */
+	if (!need_to_create_worker(pool)) {
+		/*
+		 * The pool has idle workers and doesn't need the rescuer, so it
+		 * could simply return false here.
+		 *
+		 * However, the memory pressure might not be fully relieved.
+		 * In PERCPU pool with concurrency enabled, having idle workers
+		 * does not necessarily mean memory pressure is gone; it may
+		 * simply mean regular workers have woken up, completed their
+		 * work, and gone idle again due to concurrency limits.
+		 *
+		 * In this case, those working workers may later sleep again,
+		 * the pool may run out of idle workers, and it will have to
+		 * allocate new ones and wait for the timer to send mayday,
+		 * causing unnecessary delay - especially if memory pressure
+		 * was never resolved throughout.
+		 *
+		 * Do more work if memory pressure is still on to reduce
+		 * relapse, using (pool->flags & POOL_MANAGER_ACTIVE), though
+		 * not precisely, unless there are other PWQs needing help.
+		 */
+		if (!(pool->flags & POOL_MANAGER_ACTIVE) ||
+		    !list_empty(&pwq->wq->maydays))
+			return false;
+	}
+
+	/* search from the start or cursor if available */
+	if (list_empty(&cursor->entry))
+		work = list_first_entry(&pool->worklist, struct work_struct, entry);
+	else
+		work = list_next_entry(cursor, entry);
+
+	/* find the next work item to rescue */
+	list_for_each_entry_safe_from(work, n, &pool->worklist, entry) {
+		if (get_work_pwq(work) == pwq && assign_work(work, rescuer, &n)) {
+			pwq->stats[PWQ_STAT_RESCUED]++;
+			/* put the cursor for next search */
+			list_move_tail(&cursor->entry, &n->entry);
+			return true;
+		}
+	}
+
+	return false;
+}
+
 /**
  * rescuer_thread - the rescuer thread function
  * @__rescuer: self
@@ -3497,7 +3566,7 @@ repeat:
 		struct pool_workqueue *pwq = list_first_entry(&wq->maydays,
 					struct pool_workqueue, mayday_node);
 		struct worker_pool *pool = pwq->pool;
-		struct work_struct *work, *n;
+		unsigned int count = 0;
 
 		__set_current_state(TASK_RUNNING);
 		list_del_init(&pwq->mayday_node);
@@ -3508,43 +3577,29 @@ repeat:
 
 		raw_spin_lock_irq(&pool->lock);
 
-		/*
-		 * Slurp in all works issued via this workqueue and
-		 * process'em.
-		 */
 		WARN_ON_ONCE(!list_empty(&rescuer->scheduled));
-		list_for_each_entry_safe(work, n, &pool->worklist, entry) {
-			if (get_work_pwq(work) == pwq &&
-			    assign_work(work, rescuer, &n))
-				pwq->stats[PWQ_STAT_RESCUED]++;
-		}
 
-		if (!list_empty(&rescuer->scheduled)) {
+		while (assign_rescuer_work(pwq, rescuer)) {
 			process_scheduled_works(rescuer);
 
 			/*
-			 * The above execution of rescued work items could
-			 * have created more to rescue through
-			 * pwq_activate_first_inactive() or chained
-			 * queueing.  Let's put @pwq back on mayday list so
-			 * that such back-to-back work items, which may be
-			 * being used to relieve memory pressure, don't
-			 * incur MAYDAY_INTERVAL delay inbetween.
+			 * If the per-turn work item limit is reached and other
+			 * PWQs are in mayday, requeue mayday for this PWQ and
+			 * let the rescuer handle the other PWQs first.
 			 */
-			if (pwq->nr_active && need_to_create_worker(pool)) {
+			if (++count > RESCUER_BATCH && !list_empty(&pwq->wq->maydays) &&
+			    pwq->nr_active && need_to_create_worker(pool)) {
 				raw_spin_lock(&wq_mayday_lock);
-				/*
-				 * Queue iff we aren't racing destruction
-				 * and somebody else hasn't queued it already.
-				 */
-				if (wq->rescuer && list_empty(&pwq->mayday_node)) {
-					get_pwq(pwq);
-					list_add_tail(&pwq->mayday_node, &wq->maydays);
-				}
+				send_mayday(pwq);
 				raw_spin_unlock(&wq_mayday_lock);
+				break;
 			}
 		}
 
+		/* The cursor can not be left behind without the rescuer watching it. */
+		if (!list_empty(&pwq->mayday_cursor.entry) && list_empty(&pwq->mayday_node))
+			list_del_init(&pwq->mayday_cursor.entry);
+
 		/*
 		 * Leave this pool. Notify regular workers; otherwise, we end up
 		 * with 0 concurrency and stalling the execution.
@@ -4660,7 +4715,7 @@ struct workqueue_attrs *alloc_workqueue_attrs_noprof(void)
 {
 	struct workqueue_attrs *attrs;
 
-	attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
+	attrs = kzalloc_obj(*attrs);
 	if (!attrs)
 		goto fail;
 	if (!alloc_cpumask_var(&attrs->cpumask, GFP_KERNEL))
@@ -4796,7 +4851,7 @@ static int init_worker_pool(struct worker_pool *pool)
 	pool->cpu = -1;
 	pool->node = NUMA_NO_NODE;
 	pool->flags |= POOL_DISASSOCIATED;
-	pool->watchdog_ts = jiffies;
+	pool->last_progress_ts = jiffies;
 	INIT_LIST_HEAD(&pool->worklist);
 	INIT_LIST_HEAD(&pool->idle_list);
 	hash_init(pool->busy_hash);
@@ -5163,6 +5218,19 @@ static void init_pwq(struct pool_workqueue *pwq, struct workqueue_struct *wq,
 	INIT_LIST_HEAD(&pwq->pwqs_node);
 	INIT_LIST_HEAD(&pwq->mayday_node);
 	kthread_init_work(&pwq->release_work, pwq_release_workfn);
+
+	/*
+	 * Set the dummy cursor work with valid function and get_work_pwq().
+	 *
+	 * The cursor work should only be in the pwq->pool->worklist, and
+	 * should not be treated as a processable work item.
+	 *
+	 * WORK_STRUCT_PENDING and WORK_STRUCT_INACTIVE just make it less
+	 * surprise for kernel debugging tools and reviewers.
+	 */
+	INIT_WORK(&pwq->mayday_cursor, mayday_cursor_func);
+	atomic_long_set(&pwq->mayday_cursor.data, (unsigned long)pwq |
+			WORK_STRUCT_PENDING | WORK_STRUCT_PWQ | WORK_STRUCT_INACTIVE);
 }
 
 /* sync @pwq with the current state of its associated wq and link it */
@@ -5303,7 +5371,7 @@ apply_wqattrs_prepare(struct workqueue_struct *wq,
 		    attrs->affn_scope >= WQ_AFFN_NR_TYPES))
 		return ERR_PTR(-EINVAL);
 
-	ctx = kzalloc(struct_size(ctx, pwq_tbl, nr_cpu_ids), GFP_KERNEL);
+	ctx = kzalloc_flex(*ctx, pwq_tbl, nr_cpu_ids);
 
 	new_attrs = alloc_workqueue_attrs();
 	if (!ctx || !new_attrs)
@@ -5376,11 +5444,6 @@ static void apply_wqattrs_commit(struct apply_wqattrs_ctx *ctx)
 	/* update node_nr_active->max */
 	wq_update_node_max_active(ctx->wq, -1);
 
-	/* rescuer needs to respect wq cpumask changes */
-	if (ctx->wq->rescuer)
-		set_cpus_allowed_ptr(ctx->wq->rescuer->task,
-				     unbound_effective_cpumask(ctx->wq));
-
 	mutex_unlock(&ctx->wq->mutex);
 }
 
@@ -5614,10 +5677,13 @@ static int init_rescuer(struct workqueue_struct *wq)
 	}
 
 	wq->rescuer = rescuer;
-	if (wq->flags & WQ_UNBOUND)
-		kthread_bind_mask(rescuer->task, unbound_effective_cpumask(wq));
+
+	/* initial cpumask is consistent with the detached rescuer and unbind_worker() */
+	if (cpumask_intersects(wq_unbound_cpumask, cpu_active_mask))
+		kthread_bind_mask(rescuer->task, wq_unbound_cpumask);
 	else
 		kthread_bind_mask(rescuer->task, cpu_possible_mask);
+
 	wake_up_process(rescuer->task);
 
 	return 0;
@@ -5902,16 +5968,10 @@ void destroy_workqueue(struct workqueue_struct *wq)
 
 	/* kill rescuer, if sanity checks fail, leave it w/o rescuer */
 	if (wq->rescuer) {
-		struct worker *rescuer = wq->rescuer;
-
-		/* this prevents new queueing */
-		raw_spin_lock_irq(&wq_mayday_lock);
-		wq->rescuer = NULL;
-		raw_spin_unlock_irq(&wq_mayday_lock);
-
 		/* rescuer will empty maydays list before exiting */
-		kthread_stop(rescuer->task);
-		kfree(rescuer);
+		kthread_stop(wq->rescuer->task);
+		kfree(wq->rescuer);
+		wq->rescuer = NULL;
 	}
 
 	/*
@@ -6215,7 +6275,7 @@ static void pr_cont_worker_id(struct worker *worker)
 {
 	struct worker_pool *pool = worker->pool;
 
-	if (pool->flags & WQ_BH)
+	if (pool->flags & POOL_BH)
 		pr_cont("bh%s",
 			pool->attrs->nice == HIGHPRI_NICE_LEVEL ? "-hi" : "");
 	else
@@ -6300,6 +6360,8 @@ static void show_pwq(struct pool_workqueue *pwq)
 			pr_cont(" %s", comma ? "," : "");
 			pr_cont_worker_id(worker);
 			pr_cont(":%ps", worker->current_func);
+			pr_cont(" for %us",
+				jiffies_to_msecs(jiffies - worker->current_start) / 1000);
 			list_for_each_entry(work, &worker->scheduled, entry)
 				pr_cont_work(false, work, &pcws);
 			pr_cont_work_flush(comma, (work_func_t)-1L, &pcws);
@@ -6403,7 +6465,7 @@ static void show_one_worker_pool(struct worker_pool *pool)
 
 	/* How long the first pending work is waiting for a worker. */
 	if (!list_empty(&pool->worklist))
-		hung = jiffies_to_msecs(jiffies - pool->watchdog_ts) / 1000;
+		hung = jiffies_to_msecs(jiffies - pool->last_progress_ts) / 1000;
 
 	/*
 	 * Defer printing to avoid deadlocks in console drivers that
@@ -6937,21 +6999,42 @@ static int workqueue_apply_unbound_cpumask(const cpumask_var_t unbound_cpumask)
 	}
 
 	if (!ret) {
+		int cpu;
+		struct worker_pool *pool;
+		struct worker *worker;
+
 		mutex_lock(&wq_pool_attach_mutex);
 		cpumask_copy(wq_unbound_cpumask, unbound_cpumask);
+		/* rescuer needs to respect cpumask changes when it is not attached */
+		list_for_each_entry(wq, &workqueues, list) {
+			if (wq->rescuer && !wq->rescuer->pool)
+				unbind_worker(wq->rescuer);
+		}
+		/* DISASSOCIATED worker needs to respect wq_unbound_cpumask */
+		for_each_possible_cpu(cpu) {
+			for_each_cpu_worker_pool(pool, cpu) {
+				if (!(pool->flags & POOL_DISASSOCIATED))
+					continue;
+				for_each_pool_worker(worker, pool)
+					unbind_worker(worker);
+			}
+		}
 		mutex_unlock(&wq_pool_attach_mutex);
 	}
 	return ret;
 }
 
 /**
- * workqueue_unbound_exclude_cpumask - Exclude given CPUs from unbound cpumask
- * @exclude_cpumask: the cpumask to be excluded from wq_unbound_cpumask
+ * workqueue_unbound_housekeeping_update - Propagate housekeeping cpumask update
+ * @hk: the new housekeeping cpumask
+ *
+ * Update the unbound workqueue cpumask on top of the new housekeeping cpumask such
+ * that the effective unbound affinity is the intersection of the new housekeeping
+ * with the requested affinity set via nohz_full=/isolcpus= or sysfs.
  *
- * This function can be called from cpuset code to provide a set of isolated
- * CPUs that should be excluded from wq_unbound_cpumask.
+ * Return: 0 on success and -errno on failure.
  */
-int workqueue_unbound_exclude_cpumask(cpumask_var_t exclude_cpumask)
+int workqueue_unbound_housekeeping_update(const struct cpumask *hk)
 {
 	cpumask_var_t cpumask;
 	int ret = 0;
@@ -6967,14 +7050,14 @@ int workqueue_unbound_exclude_cpumask(cpumask_var_t exclude_cpumask)
 	 * (HK_TYPE_WQ ∩ HK_TYPE_DOMAIN) house keeping mask and rewritten
 	 * by any subsequent write to workqueue/cpumask sysfs file.
 	 */
-	if (!cpumask_andnot(cpumask, wq_requested_unbound_cpumask, exclude_cpumask))
+	if (!cpumask_and(cpumask, wq_requested_unbound_cpumask, hk))
 		cpumask_copy(cpumask, wq_requested_unbound_cpumask);
 	if (!cpumask_equal(cpumask, wq_unbound_cpumask))
 		ret = workqueue_apply_unbound_cpumask(cpumask);
 
 	/* Save the current isolated cpumask & export it via sysfs */
 	if (!ret)
-		cpumask_copy(wq_isolated_cpumask, exclude_cpumask);
+		cpumask_andnot(wq_isolated_cpumask, cpu_possible_mask, hk);
 
 	mutex_unlock(&wq_pool_mutex);
 	free_cpumask_var(cpumask);
@@ -7406,7 +7489,7 @@ int workqueue_sysfs_register(struct workqueue_struct *wq)
 	if (WARN_ON(wq->flags & __WQ_ORDERED))
 		return -EINVAL;
 
-	wq->wq_dev = wq_dev = kzalloc(sizeof(*wq_dev), GFP_KERNEL);
+	wq->wq_dev = wq_dev = kzalloc_obj(*wq_dev);
 	if (!wq_dev)
 		return -ENOMEM;
 
@@ -7491,16 +7574,20 @@ static struct timer_list wq_watchdog_timer;
 static unsigned long wq_watchdog_touched = INITIAL_JIFFIES;
 static DEFINE_PER_CPU(unsigned long, wq_watchdog_touched_cpu) = INITIAL_JIFFIES;
 
-static unsigned int wq_panic_on_stall;
+static unsigned int wq_panic_on_stall = CONFIG_BOOTPARAM_WQ_STALL_PANIC;
 module_param_named(panic_on_stall, wq_panic_on_stall, uint, 0644);
 
+static unsigned int wq_panic_on_stall_time;
+module_param_named(panic_on_stall_time, wq_panic_on_stall_time, uint, 0644);
+MODULE_PARM_DESC(panic_on_stall_time, "Panic if stall exceeds this many seconds (0=disabled)");
+
 /*
  * Show workers that might prevent the processing of pending work items.
- * The only candidates are CPU-bound workers in the running state.
- * Pending work items should be handled by another idle worker
- * in all other situations.
+ * A busy worker that is not running on the CPU (e.g. sleeping in
+ * wait_event_idle() with PF_WQ_WORKER cleared) can stall the pool just as
+ * effectively as a CPU-bound one, so dump every in-flight worker.
  */
-static void show_cpu_pool_hog(struct worker_pool *pool)
+static void show_cpu_pool_busy_workers(struct worker_pool *pool)
 {
 	struct worker *worker;
 	unsigned long irq_flags;
@@ -7509,50 +7596,59 @@ static void show_cpu_pool_hog(struct worker_pool *pool)
 	raw_spin_lock_irqsave(&pool->lock, irq_flags);
 
 	hash_for_each(pool->busy_hash, bkt, worker, hentry) {
-		if (task_is_running(worker->task)) {
-			/*
-			 * Defer printing to avoid deadlocks in console
-			 * drivers that queue work while holding locks
-			 * also taken in their write paths.
-			 */
-			printk_deferred_enter();
+		/*
+		 * Defer printing to avoid deadlocks in console
+		 * drivers that queue work while holding locks
+		 * also taken in their write paths.
+		 */
+		printk_deferred_enter();
 
-			pr_info("pool %d:\n", pool->id);
-			sched_show_task(worker->task);
+		pr_info("pool %d:\n", pool->id);
+		sched_show_task(worker->task);
 
-			printk_deferred_exit();
-		}
+		printk_deferred_exit();
 	}
 
 	raw_spin_unlock_irqrestore(&pool->lock, irq_flags);
 }
 
-static void show_cpu_pools_hogs(void)
+static void show_cpu_pools_busy_workers(void)
 {
 	struct worker_pool *pool;
 	int pi;
 
-	pr_info("Showing backtraces of running workers in stalled CPU-bound worker pools:\n");
+	pr_info("Showing backtraces of busy workers in stalled worker pools:\n");
 
 	rcu_read_lock();
 
 	for_each_pool(pool, pi) {
 		if (pool->cpu_stall)
-			show_cpu_pool_hog(pool);
+			show_cpu_pool_busy_workers(pool);
 
 	}
 
 	rcu_read_unlock();
 }
 
-static void panic_on_wq_watchdog(void)
+/*
+ * It triggers a panic in two scenarios: when the total number of stalls
+ * exceeds a threshold, and when a stall lasts longer than
+ * wq_panic_on_stall_time
+ */
+static void panic_on_wq_watchdog(unsigned int stall_time_sec)
 {
 	static unsigned int wq_stall;
 
 	if (wq_panic_on_stall) {
 		wq_stall++;
-		BUG_ON(wq_stall >= wq_panic_on_stall);
+		if (wq_stall >= wq_panic_on_stall)
+			panic("workqueue: %u stall(s) exceeded threshold %u\n",
+			      wq_stall, wq_panic_on_stall);
 	}
+
+	if (wq_panic_on_stall_time && stall_time_sec >= wq_panic_on_stall_time)
+		panic("workqueue: stall lasted %us, exceeding threshold %us\n",
+		      stall_time_sec, wq_panic_on_stall_time);
 }
 
 static void wq_watchdog_reset_touched(void)
@@ -7567,10 +7663,12 @@ static void wq_watchdog_reset_touched(void)
 static void wq_watchdog_timer_fn(struct timer_list *unused)
 {
 	unsigned long thresh = READ_ONCE(wq_watchdog_thresh) * HZ;
+	unsigned int max_stall_time = 0;
 	bool lockup_detected = false;
 	bool cpu_pool_stall = false;
 	unsigned long now = jiffies;
 	struct worker_pool *pool;
+	unsigned int stall_time;
 	int pi;
 
 	if (!thresh)
@@ -7594,7 +7692,7 @@ static void wq_watchdog_timer_fn(struct timer_list *unused)
 			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);
+		pool_ts = READ_ONCE(pool->last_progress_ts);
 
 		if (time_after(pool_ts, touched))
 			ts = pool_ts;
@@ -7604,14 +7702,15 @@ static void wq_watchdog_timer_fn(struct timer_list *unused)
 		/* did we stall? */
 		if (time_after(now, ts + thresh)) {
 			lockup_detected = true;
+			stall_time = jiffies_to_msecs(now - pool_ts) / 1000;
+			max_stall_time = max(max_stall_time, stall_time);
 			if (pool->cpu >= 0 && !(pool->flags & POOL_BH)) {
 				pool->cpu_stall = true;
 				cpu_pool_stall = true;
 			}
 			pr_emerg("BUG: workqueue lockup - pool");
 			pr_cont_pool_info(pool);
-			pr_cont(" stuck for %us!\n",
-				jiffies_to_msecs(now - pool_ts) / 1000);
+			pr_cont(" stuck for %us!\n", stall_time);
 		}
 
 
@@ -7621,10 +7720,10 @@ static void wq_watchdog_timer_fn(struct timer_list *unused)
 		show_all_workqueues();
 
 	if (cpu_pool_stall)
-		show_cpu_pools_hogs();
+		show_cpu_pools_busy_workers();
 
 	if (lockup_detected)
-		panic_on_wq_watchdog();
+		panic_on_wq_watchdog(max_stall_time);
 
 	wq_watchdog_reset_touched();
 	mod_timer(&wq_watchdog_timer, jiffies + thresh);
@@ -7781,9 +7880,9 @@ void __init workqueue_init_early(void)
 		wq_power_efficient = true;
 
 	/* initialize WQ_AFFN_SYSTEM pods */
-	pt->pod_cpus = kcalloc(1, sizeof(pt->pod_cpus[0]), GFP_KERNEL);
-	pt->pod_node = kcalloc(1, sizeof(pt->pod_node[0]), GFP_KERNEL);
-	pt->cpu_pod = kcalloc(nr_cpu_ids, sizeof(pt->cpu_pod[0]), GFP_KERNEL);
+	pt->pod_cpus = kzalloc_objs(pt->pod_cpus[0], 1);
+	pt->pod_node = kzalloc_objs(pt->pod_node[0], 1);
+	pt->cpu_pod = kzalloc_objs(pt->cpu_pod[0], nr_cpu_ids);
 	BUG_ON(!pt->pod_cpus || !pt->pod_node || !pt->cpu_pod);
 
 	BUG_ON(!zalloc_cpumask_var_node(&pt->pod_cpus[0], GFP_KERNEL, NUMA_NO_NODE));
@@ -7965,7 +8064,7 @@ static void __init init_pod_type(struct wq_pod_type *pt,
 	pt->nr_pods = 0;
 
 	/* init @pt->cpu_pod[] according to @cpus_share_pod() */
-	pt->cpu_pod = kcalloc(nr_cpu_ids, sizeof(pt->cpu_pod[0]), GFP_KERNEL);
+	pt->cpu_pod = kzalloc_objs(pt->cpu_pod[0], nr_cpu_ids);
 	BUG_ON(!pt->cpu_pod);
 
 	for_each_possible_cpu(cur) {
@@ -7982,8 +8081,8 @@ static void __init init_pod_type(struct wq_pod_type *pt,
 	}
 
 	/* init the rest to match @pt->cpu_pod[] */
-	pt->pod_cpus = kcalloc(pt->nr_pods, sizeof(pt->pod_cpus[0]), GFP_KERNEL);
-	pt->pod_node = kcalloc(pt->nr_pods, sizeof(pt->pod_node[0]), GFP_KERNEL);
+	pt->pod_cpus = kzalloc_objs(pt->pod_cpus[0], pt->nr_pods);
+	pt->pod_node = kzalloc_objs(pt->pod_node[0], pt->nr_pods);
 	BUG_ON(!pt->pod_cpus || !pt->pod_node);
 
 	for (pod = 0; pod < pt->nr_pods; pod++)