engines/io_uring: don't mess with non power-of-2 queue depth

io_uring needs the rings to be a power-of-2 in sizing, but it does not
need to be messing with the queue depth driven to the device. Rather
than round everything up, only round up the API parts.

Reported-by: Riley Thomasson <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

engines/io_uring.c

@@ -759,7 +759,8 @@ static enum fio_q_status fio_ioring_queue(struct thread_data *td,
 
 	fio_ro_check(td, io_u);
 
-	if (ld->queued == ld->iodepth)
+	/* should not hit... */
+	if (ld->queued == td->o.iodepth)
 		return FIO_Q_BUSY;
 
 	/* if async trim has been tried and failed, punt to sync */
@@ -995,7 +996,7 @@ static int fio_ioring_queue_init(struct thread_data *td)
 {
 	struct ioring_data *ld = td->io_ops_data;
 	struct ioring_options *o = td->eo;
-	int depth = td->o.iodepth;
+	int depth = ld->iodepth;
 	struct io_uring_params p;
 	int ret;
 
@@ -1075,7 +1076,7 @@ static int fio_ioring_cmd_queue_init(struct thread_data *td)
 {
 	struct ioring_data *ld = td->io_ops_data;
 	struct ioring_options *o = td->eo;
-	int depth = td->o.iodepth;
+	int depth = ld->iodepth;
 	struct io_uring_params p;
 	int ret;
 
@@ -1220,7 +1221,7 @@ static int fio_ioring_post_init(struct thread_data *td)
 		return 1;
 	}
 
-	for (i = 0; i < td->o.iodepth; i++) {
+	for (i = 0; i < ld->iodepth; i++) {
 		struct io_uring_sqe *sqe;
 
 		sqe = &ld->sqes[i];
@@ -1261,7 +1262,7 @@ static int fio_ioring_cmd_post_init(struct thread_data *td)
 		return 1;
 	}
 
-	for (i = 0; i < td->o.iodepth; i++) {
+	for (i = 0; i < ld->iodepth; i++) {
 		struct io_uring_sqe *sqe;
 
 		if (o->cmd_type == FIO_URING_CMD_NVME) {
@@ -1319,9 +1320,13 @@ static int fio_ioring_init(struct thread_data *td)
 
 	ld = calloc(1, sizeof(*ld));
 
-	/* ring depth must be a power-of-2 */
-	ld->iodepth = td->o.iodepth;
-	td->o.iodepth = roundup_pow2(td->o.iodepth);
+	/*
+	 * The internal io_uring queue depth must be a power-of-2, as that's
+	 * how the ring interface works. So round that up, in case the user
+	 * set iodepth isn't a power-of-2. Leave the fio depth the same, as
+	 * not to be driving too much of an iodepth, if we did round up.
+	 */
+	ld->iodepth = roundup_pow2(td->o.iodepth);
 
 	/* io_u index */
 	ld->io_u_index = calloc(td->o.iodepth, sizeof(struct io_u *));
@@ -1351,7 +1356,7 @@ static int fio_ioring_init(struct thread_data *td)
 	}
 	parse_prchk_flags(o);
 
-	ld->iovecs = calloc(td->o.iodepth, sizeof(struct iovec));
+	ld->iovecs = calloc(ld->iodepth, sizeof(struct iovec));
 
 	td->io_ops_data = ld;