Commit cb9ccfb4 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/nop: add IORING_NOP_TW completion flag 



To test and profile the overhead of io_uring task_work and the various
types of it, add IORING_NOP_TW which tells nop to signal completions
through task_work rather than complete them inline.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ecf47d45

include/uapi/linux/io_uring.h

+1 −0
Original line number Diff line number Diff line
@@ -449,6 +449,7 @@ enum io_uring_msg_ring_flags { 
#define IORING_NOP_FILE			(1U << 1)

#define IORING_NOP_FIXED_FILE		(1U << 2)

#define IORING_NOP_FIXED_BUFFER		(1U << 3)

#define IORING_NOP_TW			(1U << 4)



/*

 * IO completion data structure (Completion Queue Entry)

io_uring/nop.c

+7 −1
Original line number Diff line number Diff line
@@ -20,7 +20,8 @@ struct io_nop { 
};



#define NOP_FLAGS	(IORING_NOP_INJECT_RESULT | IORING_NOP_FIXED_FILE | \

			 IORING_NOP_FIXED_BUFFER | IORING_NOP_FILE)

			 IORING_NOP_FIXED_BUFFER | IORING_NOP_FILE | \

			 IORING_NOP_TW)



int io_nop_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)

{
@@ -68,5 +69,10 @@ int io_nop(struct io_kiocb *req, unsigned int issue_flags) 
	if (ret < 0)

		req_set_fail(req);

	io_req_set_res(req, nop->result, 0);

	if (nop->flags & IORING_NOP_TW) {

		req->io_task_work.func = io_req_task_complete;

		io_req_task_work_add(req);

		return IOU_ISSUE_SKIP_COMPLETE;

	}

	return IOU_COMPLETE;

}