From d2c1d40487bb1884be085c187233084f80df052d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 12 Mar 2013 11:30:04 -0700 Subject: [PATCH] workqueue: restructure __alloc_workqueue_key() * Move initialization and linking of pool_workqueues into init_and_link_pwq(). * Make the failure path use destroy_workqueue() once pool_workqueue initialization succeeds. These changes are to prepare for dynamic management of pool_workqueues and don't introduce any functional changes. While at it, convert list_del(&wq->list) to list_del_init() as a precaution as scheduled changes will make destruction more complex. Signed-off-by: Tejun Heo Reviewed-by: Lai Jiangshan --- kernel/workqueue.c | 67 ++++++++++++++++++++++++++-------------------- 1 file changed, 38 insertions(+), 29 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 7ff2b9c5cc3a..5ac846e0085e 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -3329,6 +3329,23 @@ fail: return NULL; } +/* initialize @pwq which interfaces with @pool for @wq and link it in */ +static void init_and_link_pwq(struct pool_workqueue *pwq, + struct workqueue_struct *wq, + struct worker_pool *pool) +{ + BUG_ON((unsigned long)pwq & WORK_STRUCT_FLAG_MASK); + + pwq->pool = pool; + pwq->wq = wq; + pwq->flush_color = -1; + pwq->max_active = wq->saved_max_active; + INIT_LIST_HEAD(&pwq->delayed_works); + INIT_LIST_HEAD(&pwq->mayday_node); + + list_add_tail_rcu(&pwq->pwqs_node, &wq->pwqs); +} + static int alloc_and_link_pwqs(struct workqueue_struct *wq) { bool highpri = wq->flags & WQ_HIGHPRI; @@ -3345,23 +3362,23 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq) struct worker_pool *cpu_pools = per_cpu(cpu_worker_pools, cpu); - pwq->pool = &cpu_pools[highpri]; - list_add_tail_rcu(&pwq->pwqs_node, &wq->pwqs); + init_and_link_pwq(pwq, wq, &cpu_pools[highpri]); } } else { struct pool_workqueue *pwq; + struct worker_pool *pool; pwq = kmem_cache_zalloc(pwq_cache, GFP_KERNEL); if (!pwq) return -ENOMEM; - pwq->pool = get_unbound_pool(unbound_std_wq_attrs[highpri]); - if (!pwq->pool) { + pool = get_unbound_pool(unbound_std_wq_attrs[highpri]); + if (!pool) { kmem_cache_free(pwq_cache, pwq); return -ENOMEM; } - list_add_tail_rcu(&pwq->pwqs_node, &wq->pwqs); + init_and_link_pwq(pwq, wq, pool); } return 0; @@ -3406,7 +3423,7 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, wq = kzalloc(sizeof(*wq) + namelen, GFP_KERNEL); if (!wq) - goto err; + return NULL; vsnprintf(wq->name, namelen, fmt, args1); va_end(args); @@ -3429,18 +3446,7 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, INIT_LIST_HEAD(&wq->list); if (alloc_and_link_pwqs(wq) < 0) - goto err; - - local_irq_disable(); - for_each_pwq(pwq, wq) { - BUG_ON((unsigned long)pwq & WORK_STRUCT_FLAG_MASK); - pwq->wq = wq; - pwq->flush_color = -1; - pwq->max_active = max_active; - INIT_LIST_HEAD(&pwq->delayed_works); - INIT_LIST_HEAD(&pwq->mayday_node); - } - local_irq_enable(); + goto err_free_wq; /* * Workqueues which may be used during memory reclaim should @@ -3449,16 +3455,19 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, if (flags & WQ_MEM_RECLAIM) { struct worker *rescuer; - wq->rescuer = rescuer = alloc_worker(); + rescuer = alloc_worker(); if (!rescuer) - goto err; + goto err_destroy; rescuer->rescue_wq = wq; rescuer->task = kthread_create(rescuer_thread, rescuer, "%s", wq->name); - if (IS_ERR(rescuer->task)) - goto err; + if (IS_ERR(rescuer->task)) { + kfree(rescuer); + goto err_destroy; + } + wq->rescuer = rescuer; rescuer->task->flags |= PF_THREAD_BOUND; wake_up_process(rescuer->task); } @@ -3479,12 +3488,12 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, spin_unlock_irq(&workqueue_lock); return wq; -err: - if (wq) { - free_pwqs(wq); - kfree(wq->rescuer); - kfree(wq); - } + +err_free_wq: + kfree(wq); + return NULL; +err_destroy: + destroy_workqueue(wq); return NULL; } EXPORT_SYMBOL_GPL(__alloc_workqueue_key); @@ -3526,7 +3535,7 @@ void destroy_workqueue(struct workqueue_struct *wq) * wq list is used to freeze wq, remove from list after * flushing is complete in case freeze races us. */ - list_del(&wq->list); + list_del_init(&wq->list); spin_unlock_irq(&workqueue_lock); -- 2.20.1