kyber: covert to use request_queue->async_depth

Instead of the internal async_depth, remove kqd->async_depth and related
helpers.

Noted elevator attribute async_depth is now removed, queue attribute
with the same name is used instead.

Signed-off-by: Yu Kuai <yukuai@fnnas.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: hailan94

block/kyber-iosched.c

@@ -47,9 +47,8 @@ enum {
 	 * asynchronous requests, we reserve 25% of requests for synchronous
 	 * operations.
 	 */
-	KYBER_ASYNC_PERCENT = 75,
+	KYBER_DEFAULT_ASYNC_PERCENT = 75,
 };
-
 /*
  * Maximum device-wide depth for each scheduling domain.
  *
@@ -157,9 +156,6 @@ struct kyber_queue_data {
 	 */
 	struct sbitmap_queue domain_tokens[KYBER_NUM_DOMAINS];
 
-	/* Number of allowed async requests. */
-	unsigned int async_depth;
-
 	struct kyber_cpu_latency __percpu *cpu_latency;
 
 	/* Timer for stats aggregation and adjusting domain tokens. */
@@ -401,10 +397,7 @@ static struct kyber_queue_data *kyber_queue_data_alloc(struct request_queue *q)
 
 static void kyber_depth_updated(struct request_queue *q)
 {
-	struct kyber_queue_data *kqd = q->elevator->elevator_data;
-
-	kqd->async_depth = q->nr_requests * KYBER_ASYNC_PERCENT / 100U;
-	blk_mq_set_min_shallow_depth(q, kqd->async_depth);
+	blk_mq_set_min_shallow_depth(q, q->async_depth);
 }
 
 static int kyber_init_sched(struct request_queue *q, struct elevator_queue *eq)
@@ -414,6 +407,7 @@ static int kyber_init_sched(struct request_queue *q, struct elevator_queue *eq)
 	blk_queue_flag_clear(QUEUE_FLAG_SQ_SCHED, q);
 
 	q->elevator = eq;
+	q->async_depth = q->nr_requests * KYBER_DEFAULT_ASYNC_PERCENT / 100;
 	kyber_depth_updated(q);
 
 	return 0;
@@ -552,15 +546,8 @@ static void rq_clear_domain_token(struct kyber_queue_data *kqd,
 
 static void kyber_limit_depth(blk_opf_t opf, struct blk_mq_alloc_data *data)
 {
-	/*
-	 * We use the scheduler tags as per-hardware queue queueing tokens.
-	 * Async requests can be limited at this stage.
-	 */
-	if (!blk_mq_is_sync_read(opf)) {
-		struct kyber_queue_data *kqd = data->q->elevator->elevator_data;
-
-		data->shallow_depth = kqd->async_depth;
-	}
+	if (!blk_mq_is_sync_read(opf))
+		data->shallow_depth = data->q->async_depth;
 }
 
 static bool kyber_bio_merge(struct request_queue *q, struct bio *bio,
@@ -956,15 +943,6 @@ KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_DISCARD, discard)
 KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_OTHER, other)
 #undef KYBER_DEBUGFS_DOMAIN_ATTRS
 
-static int kyber_async_depth_show(void *data, struct seq_file *m)
-{
-	struct request_queue *q = data;
-	struct kyber_queue_data *kqd = q->elevator->elevator_data;
-
-	seq_printf(m, "%u\n", kqd->async_depth);
-	return 0;
-}
-
 static int kyber_cur_domain_show(void *data, struct seq_file *m)
 {
 	struct blk_mq_hw_ctx *hctx = data;
@@ -990,7 +968,6 @@ static const struct blk_mq_debugfs_attr kyber_queue_debugfs_attrs[] = {
 	KYBER_QUEUE_DOMAIN_ATTRS(write),
 	KYBER_QUEUE_DOMAIN_ATTRS(discard),
 	KYBER_QUEUE_DOMAIN_ATTRS(other),
-	{"async_depth", 0400, kyber_async_depth_show},
 	{},
 };
 #undef KYBER_QUEUE_DOMAIN_ATTRS