diff options
Diffstat (limited to 'kernel/workqueue.c')
| -rw-r--r-- | kernel/workqueue.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index ee16ddb0647c..3ad6806c7161 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1051,7 +1051,7 @@ void wq_worker_running(struct task_struct *task) { struct worker *worker = kthread_data(task); - if (!worker->sleeping) + if (!READ_ONCE(worker->sleeping)) return; /* @@ -1071,7 +1071,7 @@ void wq_worker_running(struct task_struct *task) */ worker->current_at = worker->task->se.sum_exec_runtime; - worker->sleeping = 0; + WRITE_ONCE(worker->sleeping, 0); } /** @@ -1097,10 +1097,10 @@ void wq_worker_sleeping(struct task_struct *task) pool = worker->pool; /* Return if preempted before wq_worker_running() was reached */ - if (worker->sleeping) + if (READ_ONCE(worker->sleeping)) return; - worker->sleeping = 1; + WRITE_ONCE(worker->sleeping, 1); raw_spin_lock_irq(&pool->lock); /* @@ -1143,8 +1143,15 @@ void wq_worker_tick(struct task_struct *task) * If the current worker is concurrency managed and hogged the CPU for * longer than wq_cpu_intensive_thresh_us, it's automatically marked * CPU_INTENSIVE to avoid stalling other concurrency-managed work items. + * + * Set @worker->sleeping means that @worker is in the process of + * switching out voluntarily and won't be contributing to + * @pool->nr_running until it wakes up. As wq_worker_sleeping() also + * decrements ->nr_running, setting CPU_INTENSIVE here can lead to + * double decrements. The task is releasing the CPU anyway. Let's skip. + * We probably want to make this prettier in the future. */ - if ((worker->flags & WORKER_NOT_RUNNING) || + if ((worker->flags & WORKER_NOT_RUNNING) || READ_ONCE(worker->sleeping) || worker->task->se.sum_exec_runtime - worker->current_at < wq_cpu_intensive_thresh_us * NSEC_PER_USEC) return; |