diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index c911196ac893..8d0f07509ca7 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -296,7 +296,7 @@ static const struct sysrq_key_op sysrq_showregs_op = { static void sysrq_handle_showstate(int key) { show_state(); - show_workqueue_state(); + show_all_workqueues(); } static const struct sysrq_key_op sysrq_showstate_op = { .handler = sysrq_handle_showstate, diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 74d3c1efd9bb..7fee9b6cfede 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -469,7 +469,8 @@ extern bool workqueue_congested(int cpu, struct workqueue_struct *wq); extern unsigned int work_busy(struct work_struct *work); extern __printf(1, 2) void set_worker_desc(const char *fmt, ...); extern void print_worker_info(const char *log_lvl, struct task_struct *task); -extern void show_workqueue_state(void); +extern void show_all_workqueues(void); +extern void show_one_workqueue(struct workqueue_struct *wq); extern void wq_worker_comm(char *buf, size_t size, struct task_struct *task); /** diff --git a/kernel/power/process.c b/kernel/power/process.c index 37401c99b7d7..b7e7798637b8 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -94,7 +94,7 @@ static int try_to_freeze_tasks(bool user_only) todo - wq_busy, wq_busy); if (wq_busy) - show_workqueue_state(); + show_all_workqueues(); if (!wakeup || pm_debug_messages_on) { read_lock(&tasklist_lock); diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 76988f39ed5a..1a7df882f55e 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -375,6 +375,7 @@ EXPORT_SYMBOL_GPL(system_freezable_power_efficient_wq); static int worker_thread(void *__worker); static void workqueue_sysfs_unregister(struct workqueue_struct *wq); static void show_pwq(struct pool_workqueue *pwq); +static void show_one_worker_pool(struct worker_pool *pool); #define CREATE_TRACE_POINTS #include @@ -4447,7 +4448,7 @@ void destroy_workqueue(struct workqueue_struct *wq) raw_spin_unlock_irq(&pwq->pool->lock); mutex_unlock(&wq->mutex); mutex_unlock(&wq_pool_mutex); - show_workqueue_state(); + show_one_workqueue(wq); return; } raw_spin_unlock_irq(&pwq->pool->lock); @@ -4797,96 +4798,115 @@ static void show_pwq(struct pool_workqueue *pwq) } /** - * show_workqueue_state - dump workqueue state + * show_one_workqueue - dump state of specified workqueue + * @wq: workqueue whose state will be printed + */ +void show_one_workqueue(struct workqueue_struct *wq) +{ + struct pool_workqueue *pwq; + bool idle = true; + unsigned long flags; + + for_each_pwq(pwq, wq) { + if (pwq->nr_active || !list_empty(&pwq->inactive_works)) { + idle = false; + break; + } + } + if (idle) /* Nothing to print for idle workqueue */ + return; + + pr_info("workqueue %s: flags=0x%x\n", wq->name, wq->flags); + + for_each_pwq(pwq, wq) { + raw_spin_lock_irqsave(&pwq->pool->lock, flags); + if (pwq->nr_active || !list_empty(&pwq->inactive_works)) { + /* + * Defer printing to avoid deadlocks in console + * drivers that queue work while holding locks + * also taken in their write paths. + */ + printk_deferred_enter(); + show_pwq(pwq); + printk_deferred_exit(); + } + raw_spin_unlock_irqrestore(&pwq->pool->lock, flags); + /* + * We could be printing a lot from atomic context, e.g. + * sysrq-t -> show_all_workqueues(). Avoid triggering + * hard lockup. + */ + touch_nmi_watchdog(); + } + +} + +/** + * show_one_worker_pool - dump state of specified worker pool + * @pool: worker pool whose state will be printed + */ +static void show_one_worker_pool(struct worker_pool *pool) +{ + struct worker *worker; + bool first = true; + unsigned long flags; + + raw_spin_lock_irqsave(&pool->lock, flags); + if (pool->nr_workers == pool->nr_idle) + goto next_pool; + /* + * 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:", pool->id); + pr_cont_pool_info(pool); + pr_cont(" hung=%us workers=%d", + jiffies_to_msecs(jiffies - pool->watchdog_ts) / 1000, + pool->nr_workers); + if (pool->manager) + pr_cont(" manager: %d", + task_pid_nr(pool->manager->task)); + list_for_each_entry(worker, &pool->idle_list, entry) { + pr_cont(" %s%d", first ? "idle: " : "", + task_pid_nr(worker->task)); + first = false; + } + pr_cont("\n"); + printk_deferred_exit(); +next_pool: + raw_spin_unlock_irqrestore(&pool->lock, flags); + /* + * We could be printing a lot from atomic context, e.g. + * sysrq-t -> show_all_workqueues(). Avoid triggering + * hard lockup. + */ + touch_nmi_watchdog(); + +} + +/** + * show_all_workqueues - dump workqueue state * * Called from a sysrq handler or try_to_freeze_tasks() and prints out * all busy workqueues and pools. */ -void show_workqueue_state(void) +void show_all_workqueues(void) { struct workqueue_struct *wq; struct worker_pool *pool; - unsigned long flags; int pi; rcu_read_lock(); pr_info("Showing busy workqueues and worker pools:\n"); - list_for_each_entry_rcu(wq, &workqueues, list) { - struct pool_workqueue *pwq; - bool idle = true; + list_for_each_entry_rcu(wq, &workqueues, list) + show_one_workqueue(wq); - for_each_pwq(pwq, wq) { - if (pwq->nr_active || !list_empty(&pwq->inactive_works)) { - idle = false; - break; - } - } - if (idle) - continue; - - pr_info("workqueue %s: flags=0x%x\n", wq->name, wq->flags); - - for_each_pwq(pwq, wq) { - raw_spin_lock_irqsave(&pwq->pool->lock, flags); - if (pwq->nr_active || !list_empty(&pwq->inactive_works)) { - /* - * Defer printing to avoid deadlocks in console - * drivers that queue work while holding locks - * also taken in their write paths. - */ - printk_deferred_enter(); - show_pwq(pwq); - printk_deferred_exit(); - } - raw_spin_unlock_irqrestore(&pwq->pool->lock, flags); - /* - * We could be printing a lot from atomic context, e.g. - * sysrq-t -> show_workqueue_state(). Avoid triggering - * hard lockup. - */ - touch_nmi_watchdog(); - } - } - - for_each_pool(pool, pi) { - struct worker *worker; - bool first = true; - - raw_spin_lock_irqsave(&pool->lock, flags); - if (pool->nr_workers == pool->nr_idle) - goto next_pool; - /* - * 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:", pool->id); - pr_cont_pool_info(pool); - pr_cont(" hung=%us workers=%d", - jiffies_to_msecs(jiffies - pool->watchdog_ts) / 1000, - pool->nr_workers); - if (pool->manager) - pr_cont(" manager: %d", - task_pid_nr(pool->manager->task)); - list_for_each_entry(worker, &pool->idle_list, entry) { - pr_cont(" %s%d", first ? "idle: " : "", - task_pid_nr(worker->task)); - first = false; - } - pr_cont("\n"); - printk_deferred_exit(); - next_pool: - raw_spin_unlock_irqrestore(&pool->lock, flags); - /* - * We could be printing a lot from atomic context, e.g. - * sysrq-t -> show_workqueue_state(). Avoid triggering - * hard lockup. - */ - touch_nmi_watchdog(); - } + for_each_pool(pool, pi) + show_one_worker_pool(pool); rcu_read_unlock(); } @@ -5876,7 +5896,7 @@ static void wq_watchdog_timer_fn(struct timer_list *unused) rcu_read_unlock(); if (lockup_detected) - show_workqueue_state(); + show_all_workqueues(); wq_watchdog_reset_touched(); mod_timer(&wq_watchdog_timer, jiffies + thresh);