diff options
| -rw-r--r-- | kernel/workqueue.c | 77 |
1 files changed, 28 insertions, 49 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 8942cc74d83b..26c67c76b6c5 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -170,6 +170,7 @@ struct pool_workqueue { int max_active; /* L: max active works */ struct list_head delayed_works; /* L: delayed works */ struct list_head pwqs_node; /* I: node on wq->pwqs */ + struct list_head mayday_node; /* W: node on wq->maydays */ } __aligned(1 << WORK_STRUCT_FLAG_BITS); /* @@ -182,27 +183,6 @@ struct wq_flusher { }; /* - * All cpumasks are assumed to be always set on UP and thus can't be - * used to determine whether there's something to be done. - */ -#ifdef CONFIG_SMP -typedef cpumask_var_t mayday_mask_t; -#define mayday_test_and_set_cpu(cpu, mask) \ - cpumask_test_and_set_cpu((cpu), (mask)) -#define mayday_clear_cpu(cpu, mask) cpumask_clear_cpu((cpu), (mask)) -#define for_each_mayday_cpu(cpu, mask) for_each_cpu((cpu), (mask)) -#define alloc_mayday_mask(maskp, gfp) zalloc_cpumask_var((maskp), (gfp)) -#define free_mayday_mask(mask) free_cpumask_var((mask)) -#else -typedef unsigned long mayday_mask_t; -#define mayday_test_and_set_cpu(cpu, mask) test_and_set_bit(0, &(mask)) -#define mayday_clear_cpu(cpu, mask) clear_bit(0, &(mask)) -#define for_each_mayday_cpu(cpu, mask) if ((cpu) = 0, (mask)) -#define alloc_mayday_mask(maskp, gfp) true -#define free_mayday_mask(mask) do { } while (0) -#endif - -/* * The externally visible workqueue abstraction is an array of * per-CPU workqueues: */ @@ -224,7 +204,7 @@ struct workqueue_struct { struct list_head flusher_queue; /* F: flush waiters */ struct list_head flusher_overflow; /* F: flush overflow list */ - mayday_mask_t mayday_mask; /* cpus requesting rescue */ + struct list_head maydays; /* W: pwqs requesting rescue */ struct worker *rescuer; /* I: rescue worker */ int nr_drainers; /* W: drain in progress */ @@ -1850,23 +1830,21 @@ static void idle_worker_timeout(unsigned long __pool) spin_unlock_irq(&pool->lock); } -static bool send_mayday(struct work_struct *work) +static void send_mayday(struct work_struct *work) { struct pool_workqueue *pwq = get_work_pwq(work); struct workqueue_struct *wq = pwq->wq; - unsigned int cpu; + + lockdep_assert_held(&workqueue_lock); if (!(wq->flags & WQ_RESCUER)) - return false; + return; /* mayday mayday mayday */ - cpu = pwq->pool->cpu; - /* WORK_CPU_UNBOUND can't be set in cpumask, use cpu 0 instead */ - if (cpu == WORK_CPU_UNBOUND) - cpu = 0; - if (!mayday_test_and_set_cpu(cpu, wq->mayday_mask)) + if (list_empty(&pwq->mayday_node)) { + list_add_tail(&pwq->mayday_node, &wq->maydays); wake_up_process(wq->rescuer->task); - return true; + } } static void pool_mayday_timeout(unsigned long __pool) @@ -1874,7 +1852,8 @@ static void pool_mayday_timeout(unsigned long __pool) struct worker_pool *pool = (void *)__pool; struct work_struct *work; - spin_lock_irq(&pool->lock); + spin_lock_irq(&workqueue_lock); /* for wq->maydays */ + spin_lock(&pool->lock); if (need_to_create_worker(pool)) { /* @@ -1887,7 +1866,8 @@ static void pool_mayday_timeout(unsigned long __pool) send_mayday(work); } - spin_unlock_irq(&pool->lock); + spin_unlock(&pool->lock); + spin_unlock_irq(&workqueue_lock); mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INTERVAL); } @@ -2336,8 +2316,6 @@ static int rescuer_thread(void *__rescuer) struct worker *rescuer = __rescuer; struct workqueue_struct *wq = rescuer->rescue_wq; struct list_head *scheduled = &rescuer->scheduled; - bool is_unbound = wq->flags & WQ_UNBOUND; - unsigned int cpu; set_user_nice(current, RESCUER_NICE_LEVEL); @@ -2355,18 +2333,19 @@ repeat: return 0; } - /* - * See whether any cpu is asking for help. Unbounded - * workqueues use cpu 0 in mayday_mask for CPU_UNBOUND. - */ - for_each_mayday_cpu(cpu, wq->mayday_mask) { - unsigned int tcpu = is_unbound ? WORK_CPU_UNBOUND : cpu; - struct pool_workqueue *pwq = get_pwq(tcpu, wq); + /* see whether any pwq is asking for help */ + spin_lock_irq(&workqueue_lock); + + while (!list_empty(&wq->maydays)) { + 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; __set_current_state(TASK_RUNNING); - mayday_clear_cpu(cpu, wq->mayday_mask); + list_del_init(&pwq->mayday_node); + + spin_unlock_irq(&workqueue_lock); /* migrate to the target cpu if possible */ worker_maybe_bind_and_lock(pool); @@ -2392,9 +2371,12 @@ repeat: wake_up_worker(pool); rescuer->pool = NULL; - spin_unlock_irq(&pool->lock); + spin_unlock(&pool->lock); + spin_lock(&workqueue_lock); } + spin_unlock_irq(&workqueue_lock); + /* rescuers should never participate in concurrency management */ WARN_ON_ONCE(!(rescuer->flags & WORKER_NOT_RUNNING)); schedule(); @@ -3192,6 +3174,7 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, INIT_LIST_HEAD(&wq->pwqs); INIT_LIST_HEAD(&wq->flusher_queue); INIT_LIST_HEAD(&wq->flusher_overflow); + INIT_LIST_HEAD(&wq->maydays); lockdep_init_map(&wq->lockdep_map, lock_name, key, 0); INIT_LIST_HEAD(&wq->list); @@ -3205,14 +3188,12 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, pwq->flush_color = -1; pwq->max_active = max_active; INIT_LIST_HEAD(&pwq->delayed_works); + INIT_LIST_HEAD(&pwq->mayday_node); } if (flags & WQ_RESCUER) { struct worker *rescuer; - if (!alloc_mayday_mask(&wq->mayday_mask, GFP_KERNEL)) - goto err; - wq->rescuer = rescuer = alloc_worker(); if (!rescuer) goto err; @@ -3246,7 +3227,6 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, err: if (wq) { free_pwqs(wq); - free_mayday_mask(wq->mayday_mask); kfree(wq->rescuer); kfree(wq); } @@ -3289,7 +3269,6 @@ void destroy_workqueue(struct workqueue_struct *wq) if (wq->flags & WQ_RESCUER) { kthread_stop(wq->rescuer->task); - free_mayday_mask(wq->mayday_mask); kfree(wq->rescuer); } |