Re: [PATCH RESEND v5 3/7] blk-mq: add a new queue sysfs attribute async_depth

From: Bart Van Assche

Date: Mon Nov 17 2025 - 18:45:59 EST


On 11/15/25 7:52 PM, Yu Kuai wrote:
+static void blk_mq_limit_depth(struct blk_mq_alloc_data *data)
+{
+ struct elevator_mq_ops *ops;
+
+ /* If elevator is none, don't limit requests */

Nobody calls an I/O scheduler an elevator anymore. So I propose to
change "elevator is none" into "no I/O scheduler has been configured".

+ /*
+ * Flush/passthrough requests are special and go directly to the
+ * dispatch list, they don't have limit.
+ */
"they don't have a limit" -> "are not subject to the async_depth limit".

+ /*
+ * By default, sync requests have no limit, and async requests is
+ * limited to async_depth.
+ */

"is" -> "are"

> - /*
> - * All requests use scheduler tags when an I/O scheduler is
> - * enabled for the queue.
> - */
> - data->rq_flags |= RQF_SCHED_TAGS;

Why has the above comment been removed? I think that it is useful.

Additionally, please split this patch into two patches: a first patch
that introduces the function blk_mq_limit_depth() and a second patch
with the remaining changes from this patch.

Thanks,

Bart.