diff options
| -rw-r--r-- | kernel/workqueue.c | 35 |
1 files changed, 5 insertions, 30 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 092f2098746d..d6b31ff60c52 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1725,8 +1725,6 @@ static struct worker *create_worker(struct worker_pool *pool) int id = -1; char id_buf[16]; - lockdep_assert_held(&pool->manager_mutex); - /* ID is needed to determine kthread name */ id = ida_simple_get(&pool->worker_ida, 0, 0, GFP_KERNEL); if (id < 0) @@ -1755,6 +1753,8 @@ static struct worker *create_worker(struct worker_pool *pool) /* prevent userland from meddling with cpumask of workqueue workers */ worker->task->flags |= PF_NO_SETAFFINITY; + mutex_lock(&pool->manager_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. @@ -1762,7 +1762,7 @@ static struct worker *create_worker(struct worker_pool *pool) set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask); /* - * The caller is responsible for ensuring %POOL_DISASSOCIATED + * The pool->manager_mutex ensures %POOL_DISASSOCIATED * remains stable across this function. See the comments above the * flag definition for details. */ @@ -1772,6 +1772,8 @@ static struct worker *create_worker(struct worker_pool *pool) /* successful, attach the worker to the pool */ list_add_tail(&worker->node, &pool->workers); + mutex_unlock(&pool->manager_mutex); + return worker; fail: @@ -1809,8 +1811,6 @@ static int create_and_start_worker(struct worker_pool *pool) { struct worker *worker; - mutex_lock(&pool->manager_mutex); - worker = create_worker(pool); if (worker) { spin_lock_irq(&pool->lock); @@ -1818,8 +1818,6 @@ static int create_and_start_worker(struct worker_pool *pool) spin_unlock_irq(&pool->lock); } - mutex_unlock(&pool->manager_mutex); - return worker ? 0 : -ENOMEM; } @@ -2019,8 +2017,6 @@ static bool manage_workers(struct worker *worker) bool ret = false; /* - * Managership is governed by two mutexes - manager_arb and - * manager_mutex. manager_arb handles arbitration of manager role. * Anyone who successfully grabs manager_arb wins the arbitration * and becomes the manager. mutex_trylock() on pool->manager_arb * failure while holding pool->lock reliably indicates that someone @@ -2029,33 +2025,12 @@ static bool manage_workers(struct worker *worker) * grabbing manager_arb is responsible for actually performing * manager duties. If manager_arb is grabbed and released without * actual management, the pool may stall indefinitely. - * - * manager_mutex is used for exclusion of actual management - * operations. The holder of manager_mutex can be sure that none - * of management operations, including creation and destruction of - * workers, won't take place until the mutex is released. Because - * manager_mutex doesn't interfere with manager role arbitration, - * it is guaranteed that the pool's management, while may be - * delayed, won't be disturbed by someone else grabbing - * manager_mutex. */ if (!mutex_trylock(&pool->manager_arb)) return ret; - /* - * With manager arbitration won, manager_mutex would be free in - * most cases. trylock first without dropping @pool->lock. - */ - if (unlikely(!mutex_trylock(&pool->manager_mutex))) { - spin_unlock_irq(&pool->lock); - mutex_lock(&pool->manager_mutex); - spin_lock_irq(&pool->lock); - ret = true; - } - ret |= maybe_create_worker(pool); - mutex_unlock(&pool->manager_mutex); mutex_unlock(&pool->manager_arb); return ret; } |