io-wq: remove worker->wait waitqueue

We only have one cases of using the waitqueue to wake the worker, the
rest are using wake_up_process(). Since we can save some cycles not
fiddling with the waitqueue io_wqe_worker(), switch the work activation
to task wakeup and get rid of the now unused wait_queue_head_t in
struct io_worker.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 74b4050..6b663dd 100644 (file)
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -49,7 +49,6 @@ struct io_worker {
        struct hlist_nulls_node nulls_node;
        struct list_head all_list;
        struct task_struct *task;
-       wait_queue_head_t wait;
        struct io_wqe *wqe;
 
        struct io_wq_work *cur_work;
@@ -258,7 +257,7 @@ static bool io_wqe_activate_free_worker(struct io_wqe *wqe)
 
        worker = hlist_nulls_entry(n, struct io_worker, nulls_node);
        if (io_worker_get(worker)) {
-               wake_up(&worker->wait);
+               wake_up_process(worker->task);
                io_worker_release(worker);
                return true;
        }
@@ -497,13 +496,11 @@ static int io_wqe_worker(void *data)
        struct io_worker *worker = data;
        struct io_wqe *wqe = worker->wqe;
        struct io_wq *wq = wqe->wq;
-       DEFINE_WAIT(wait);
 
        io_worker_start(wqe, worker);
 
        while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
-               prepare_to_wait(&worker->wait, &wait, TASK_INTERRUPTIBLE);
-
+               set_current_state(TASK_INTERRUPTIBLE);
                spin_lock_irq(&wqe->lock);
                if (io_wqe_run_queue(wqe)) {
                        __set_current_state(TASK_RUNNING);
@@ -526,8 +523,6 @@ static int io_wqe_worker(void *data)
                        break;
        }
 
-       finish_wait(&worker->wait, &wait);
-
        if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
                spin_lock_irq(&wqe->lock);
                if (!wq_list_empty(&wqe->work_list))
@@ -589,7 +584,6 @@ static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
 
        refcount_set(&worker->ref, 1);
        worker->nulls_node.pprev = NULL;
-       init_waitqueue_head(&worker->wait);
        worker->wqe = wqe;
        spin_lock_init(&worker->lock);