Commit c6538be9 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: refactor tctx task_work list splicing 



We don't need a full copy of tctx->task_list in tctx_task_work(), but
only a first one, so just assign node directly.

Taking into account that task_works are run in a context of a task,
it's very unlikely to first see non-empty tctx->task_list and then
splice it empty, can only happen with task_work cancellations that is
not-normal slow path anyway. Hence, get rid of the check in the end,
it's there not for validity but "performance" purposes.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d076c83fedb8253baf43acb23b8fafd7c5da1714.1623949695.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ebd0df2e

fs/io_uring.c

+1 −6
Original line number Diff line number Diff line
@@ -1897,15 +1897,13 @@ static void tctx_task_work(struct callback_head *cb) 
	clear_bit(0, &tctx->task_state);



	while (!wq_list_empty(&tctx->task_list)) {

		struct io_wq_work_list list;

		struct io_wq_work_node *node;



		spin_lock_irq(&tctx->task_lock);

		list = tctx->task_list;

		node = tctx->task_list.first;

		INIT_WQ_LIST(&tctx->task_list);

		spin_unlock_irq(&tctx->task_lock);



		node = list.first;

		while (node) {

			struct io_wq_work_node *next = node->next;

			struct io_kiocb *req = container_of(node, struct io_kiocb,
@@ -1919,9 +1917,6 @@ static void tctx_task_work(struct callback_head *cb) 
			req->task_work.func(&req->task_work);

			node = next;

		}



		if (!list.first)

			break;

		cond_resched();

	}