diff options
| author | Tejun Heo <tj@kernel.org> | 2018-05-18 08:47:13 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2018-05-18 08:47:13 -0700 |
| commit | a2d812a27a4530b999a92f245d0d8291663e8c38 (patch) | |
| tree | 1b3253129ac2bfdf227cc6171cbf7578a383f8a9 | |
| parent | 1258fae73c59e918964455fdead682d79109371a (diff) | |
workqueue: Make worker_attach/detach_pool() update worker->pool
For historical reasons, the worker attach/detach functions don't
currently manage worker->pool and the callers are manually and
inconsistently updating it.
This patch moves worker->pool updates into the worker attach/detach
functions. This makes worker->pool consistent and clearly defines how
worker->pool updates are synchronized.
This will help later workqueue visibility improvements by allowing
safe access to workqueue information from worker->task.
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | kernel/workqueue.c | 16 | ||||
| -rw-r--r-- | kernel/workqueue_internal.h | 2 |
2 files changed, 9 insertions, 9 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 91fe0a6118a0..2fde50f8221b 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1741,6 +1741,7 @@ static void worker_attach_to_pool(struct worker *worker, worker->flags |= WORKER_UNBOUND; list_add_tail(&worker->node, &pool->workers); + worker->pool = pool; mutex_unlock(&wq_pool_attach_mutex); } @@ -1748,19 +1749,21 @@ static void worker_attach_to_pool(struct worker *worker, /** * worker_detach_from_pool() - detach a worker from its pool * @worker: worker which is attached to its pool - * @pool: the pool @worker is attached to * * Undo the attaching which had been done in worker_attach_to_pool(). The * caller worker shouldn't access to the pool after detached except it has * other reference to the pool. */ -static void worker_detach_from_pool(struct worker *worker, - struct worker_pool *pool) +static void worker_detach_from_pool(struct worker *worker) { + struct worker_pool *pool = worker->pool; struct completion *detach_completion = NULL; mutex_lock(&wq_pool_attach_mutex); + list_del(&worker->node); + worker->pool = NULL; + if (list_empty(&pool->workers)) detach_completion = pool->detach_completion; mutex_unlock(&wq_pool_attach_mutex); @@ -1799,7 +1802,6 @@ static struct worker *create_worker(struct worker_pool *pool) if (!worker) goto fail; - worker->pool = pool; worker->id = id; if (pool->cpu >= 0) @@ -2236,7 +2238,7 @@ woke_up: set_task_comm(worker->task, "kworker/dying"); ida_simple_remove(&pool->worker_ida, worker->id); - worker_detach_from_pool(worker, pool); + worker_detach_from_pool(worker); kfree(worker); return 0; } @@ -2367,7 +2369,6 @@ repeat: worker_attach_to_pool(rescuer, pool); spin_lock_irq(&pool->lock); - rescuer->pool = pool; /* * Slurp in all works issued via this workqueue and @@ -2417,10 +2418,9 @@ repeat: if (need_more_worker(pool)) wake_up_worker(pool); - rescuer->pool = NULL; spin_unlock_irq(&pool->lock); - worker_detach_from_pool(rescuer, pool); + worker_detach_from_pool(rescuer); spin_lock_irq(&wq_mayday_lock); } diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h index d390d1be3748..4a182e027207 100644 --- a/kernel/workqueue_internal.h +++ b/kernel/workqueue_internal.h @@ -37,7 +37,7 @@ struct worker { /* 64 bytes boundary on 64bit, 32 on 32bit */ struct task_struct *task; /* I: worker task */ - struct worker_pool *pool; /* I: the associated pool */ + struct worker_pool *pool; /* A: the associated pool */ /* L: for rescuers */ struct list_head node; /* A: anchored at pool->workers */ /* A: runs through worker->node */ |