Commit af0a2ffe authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: avoid normal tw intermediate fallback 



When a DEFER_TASKRUN io_uring is terminating it requeues deferred task
work items as normal tw, which can further fallback to kthread
execution. Avoid this extra step and always push them to the fallback
kthread.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d1cd472cec2230c66bd1c8d412a5833f0af75384.1730772720.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 6bf90bd8

io_uring/io_uring.c

+10 −11
Original line number Diff line number Diff line
@@ -1066,9 +1066,8 @@ struct llist_node *io_handle_tw_list(struct llist_node *node, 
	return node;

}



static __cold void io_fallback_tw(struct io_uring_task *tctx, bool sync)

static __cold void __io_fallback_tw(struct llist_node *node, bool sync)

{

	struct llist_node *node = llist_del_all(&tctx->task_list);

	struct io_ring_ctx *last_ctx = NULL;

	struct io_kiocb *req;
@@ -1094,6 +1093,13 @@ static __cold void io_fallback_tw(struct io_uring_task *tctx, bool sync) 
	}

}



static void io_fallback_tw(struct io_uring_task *tctx, bool sync)

{

	struct llist_node *node = llist_del_all(&tctx->task_list);



	__io_fallback_tw(node, sync);

}



struct llist_node *tctx_task_work_run(struct io_uring_task *tctx,

				      unsigned int max_entries,

				      unsigned int *count)
@@ -1247,16 +1253,9 @@ void io_req_task_work_add_remote(struct io_kiocb *req, struct io_ring_ctx *ctx, 


static void __cold io_move_task_work_from_local(struct io_ring_ctx *ctx)

{

	struct llist_node *node;

	struct llist_node *node = llist_del_all(&ctx->work_llist);



	node = llist_del_all(&ctx->work_llist);

	while (node) {

		struct io_kiocb *req = container_of(node, struct io_kiocb,

						    io_task_work.node);



		node = node->next;

		io_req_normal_work_add(req);

	}

	__io_fallback_tw(node, false);

}



static bool io_run_local_work_continue(struct io_ring_ctx *ctx, int events,

io_uring/io_uring.h

+1 −1
Original line number Diff line number Diff line
@@ -136,7 +136,7 @@ static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx *ctx) 
		 * Not from an SQE, as those cannot be submitted, but via

		 * updating tagged resources.

		 */

		if (ctx->submitter_task->flags & PF_EXITING)

		if (percpu_ref_is_dying(&ctx->refs))

			lockdep_assert(current_work());

		else

			lockdep_assert(current == ctx->submitter_task);