Commit fb27274a authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: clusterise ki_flags access in rw_prep 



ioprio setup doesn't depend on other fields that are modified in
io_prep_rw() and we can move it down in the function without worrying
about performance. It's useful as it makes iocb->ki_flags
accesses/modifications closer together, so it's more likely the compiler
will cache it in a register and avoid extra reloads.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8ee98779c06f1b59f6039b1e292db4332efd664b.1634987320.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b9a6b8f9

fs/io_uring.c

+11 −10
Original line number Diff line number Diff line
@@ -2840,16 +2840,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	    ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req)))

		req->flags |= REQ_F_NOWAIT;



	ioprio = READ_ONCE(sqe->ioprio);

	if (ioprio) {

		ret = ioprio_check_cap(ioprio);

		if (ret)

			return ret;



		kiocb->ki_ioprio = ioprio;

	} else

		kiocb->ki_ioprio = get_current_ioprio();



	if (ctx->flags & IORING_SETUP_IOPOLL) {

		if (!(kiocb->ki_flags & IOCB_DIRECT) || !file->f_op->iopoll)

			return -EOPNOTSUPP;
@@ -2863,6 +2853,17 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
		kiocb->ki_complete = io_complete_rw;

	}



	ioprio = READ_ONCE(sqe->ioprio);

	if (ioprio) {

		ret = ioprio_check_cap(ioprio);

		if (ret)

			return ret;



		kiocb->ki_ioprio = ioprio;

	} else {

		kiocb->ki_ioprio = get_current_ioprio();

	}



	req->imu = NULL;

	req->rw.addr = READ_ONCE(sqe->addr);

	req->rw.len = READ_ONCE(sqe->len);