Commit ce35a47a authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: add IOSQE_ASYNC 



io_uring defaults to always doing inline submissions, if at all
possible. But for larger copies, even if the data is fully cached, that
can take a long time. Add an IOSQE_ASYNC flag that the application can
set on the SQE - if set, it'll ensure that we always go async for those
kinds of requests. Use the io-wq IO_WQ_WORK_CONCURRENT flag to ensure we
get the concurrency we desire for this case.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 895e2ca0

fs/io_uring.c

+14 −2
Original line number Diff line number Diff line
@@ -483,6 +483,7 @@ struct io_kiocb { 
#define REQ_F_INFLIGHT		16384	/* on inflight list */

#define REQ_F_COMP_LOCKED	32768	/* completion under lock */

#define REQ_F_HARDLINK		65536	/* doesn't sever on completion < 0 */

#define REQ_F_FORCE_ASYNC	131072	/* IOSQE_ASYNC */

	u64			user_data;

	u32			result;

	u32			sequence;
@@ -4017,9 +4018,18 @@ static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
			req_set_fail_links(req);

			io_double_put_req(req);

		}

	} else

	} else if ((req->flags & REQ_F_FORCE_ASYNC) &&

		   !io_wq_current_is_worker()) {

		/*

		 * Never try inline submit of IOSQE_ASYNC is set, go straight

		 * to async execution.

		 */

		req->work.flags |= IO_WQ_WORK_CONCURRENT;

		io_queue_async_work(req);

	} else {

		__io_queue_sqe(req, sqe);

	}

}



static inline void io_queue_link_head(struct io_kiocb *req)

{
@@ -4031,7 +4041,7 @@ static inline void io_queue_link_head(struct io_kiocb *req) 
}



#define SQE_VALID_FLAGS	(IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK|	\

				IOSQE_IO_HARDLINK)

				IOSQE_IO_HARDLINK | IOSQE_ASYNC)



static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,

			  struct io_submit_state *state, struct io_kiocb **link)
@@ -4044,6 +4054,8 @@ static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, 
		ret = -EINVAL;

		goto err_req;

	}

	if (sqe->flags & IOSQE_ASYNC)

		req->flags |= REQ_F_FORCE_ASYNC;



	ret = io_req_set_file(state, req, sqe);

	if (unlikely(ret)) {

include/uapi/linux/io_uring.h

+1 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ struct io_uring_sqe { 
#define IOSQE_IO_DRAIN		(1U << 1)	/* issue after inflight IO */

#define IOSQE_IO_LINK		(1U << 2)	/* links next sqe */

#define IOSQE_IO_HARDLINK	(1U << 3)	/* like LINK, but stronger */

#define IOSQE_ASYNC		(1U << 4)	/* always go async */



/*

 * io_uring_setup() flags

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