diff mbox series

[RFC,v3,6/7] block/mq-deadline: switch to use queue async_depth

Message ID 20241221093710.926309-7-yukuai1@huaweicloud.com (mailing list archive)
State New
Headers show
Series lib/sbitmap: fix shallow_depth tag allocation | expand

Commit Message

Yu Kuai Dec. 21, 2024, 9:37 a.m. UTC 
From: Yu Kuai <yukuai3@huawei.com>

min_shallow_depth must be less or equal to any shallow_depth value, and
it's 1 currently, and this will change default wake_batch to 1, causing
performance degradation for fast disk with high concurrency.

Fix the problem by using queue async_depth, so that min_shallow_depth
can be updated if user set new value, hence it's not necessary to use 1
anymore.

Fixes: 39823b47bbd4 ("block/mq-deadline: Fix the tag reservation code")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 block/mq-deadline.c | 43 ++++++++++---------------------------------
 1 file changed, 10 insertions(+), 33 deletions(-)
diff mbox series

Patch

diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index 853985bd13d4..8d19685cce3e 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -98,7 +98,6 @@  struct deadline_data {
 	int fifo_batch;
 	int writes_starved;
 	int front_merges;
-	u32 async_depth;
 	int prio_aging_expire;
 
 	spinlock_t lock;
@@ -493,8 +492,6 @@  static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
  */
 static void dd_limit_depth(blk_opf_t opf, struct blk_mq_alloc_data *data)
 {
-	struct deadline_data *dd = data->q->elevator->elevator_data;
-
 	/* Do not throttle synchronous reads. */
 	if (op_is_sync(opf) && !op_is_write(opf))
 		return;
@@ -503,25 +500,19 @@  static void dd_limit_depth(blk_opf_t opf, struct blk_mq_alloc_data *data)
 	 * Throttle asynchronous requests and writes such that these requests
 	 * do not block the allocation of synchronous requests.
 	 */
-	data->shallow_depth = dd->async_depth;
+	data->shallow_depth = data->q->async_depth;
 }
 
-/* Called by blk_mq_update_nr_requests(). */
-static void dd_depth_updated(struct blk_mq_hw_ctx *hctx)
+static int dd_async_depth_updated(struct request_queue *q,
+				  unsigned int async_depth)
 {
-	struct request_queue *q = hctx->queue;
-	struct deadline_data *dd = q->elevator->elevator_data;
-	struct blk_mq_tags *tags = hctx->sched_tags;
-
-	dd->async_depth = q->nr_requests;
+	struct blk_mq_hw_ctx *hctx;
+	unsigned long i;
 
-	sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, 1);
-}
-
-/* Called by blk_mq_init_hctx() and blk_mq_init_sched(). */
-static int dd_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
-{
-	dd_depth_updated(hctx);
+	q->async_depth = async_depth;
+	queue_for_each_hw_ctx(q, hctx, i)
+		sbitmap_queue_min_shallow_depth(&hctx->sched_tags->bitmap_tags,
+					async_depth ? async_depth : UINT_MAX);
 	return 0;
 }
 
@@ -781,7 +772,6 @@  SHOW_JIFFIES(deadline_write_expire_show, dd->fifo_expire[DD_WRITE]);
 SHOW_JIFFIES(deadline_prio_aging_expire_show, dd->prio_aging_expire);
 SHOW_INT(deadline_writes_starved_show, dd->writes_starved);
 SHOW_INT(deadline_front_merges_show, dd->front_merges);
-SHOW_INT(deadline_async_depth_show, dd->async_depth);
 SHOW_INT(deadline_fifo_batch_show, dd->fifo_batch);
 #undef SHOW_INT
 #undef SHOW_JIFFIES
@@ -811,7 +801,6 @@  STORE_JIFFIES(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MA
 STORE_JIFFIES(deadline_prio_aging_expire_store, &dd->prio_aging_expire, 0, INT_MAX);
 STORE_INT(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX);
 STORE_INT(deadline_front_merges_store, &dd->front_merges, 0, 1);
-STORE_INT(deadline_async_depth_store, &dd->async_depth, 1, INT_MAX);
 STORE_INT(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX);
 #undef STORE_FUNCTION
 #undef STORE_INT
@@ -825,7 +814,6 @@  static struct elv_fs_entry deadline_attrs[] = {
 	DD_ATTR(write_expire),
 	DD_ATTR(writes_starved),
 	DD_ATTR(front_merges),
-	DD_ATTR(async_depth),
 	DD_ATTR(fifo_batch),
 	DD_ATTR(prio_aging_expire),
 	__ATTR_NULL
@@ -912,15 +900,6 @@  static int deadline_starved_show(void *data, struct seq_file *m)
 	return 0;
 }
 
-static int dd_async_depth_show(void *data, struct seq_file *m)
-{
-	struct request_queue *q = data;
-	struct deadline_data *dd = q->elevator->elevator_data;
-
-	seq_printf(m, "%u\n", dd->async_depth);
-	return 0;
-}
-
 static int dd_queued_show(void *data, struct seq_file *m)
 {
 	struct request_queue *q = data;
@@ -1030,7 +1009,6 @@  static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = {
 	DEADLINE_NEXT_RQ_ATTR(write2),
 	{"batching", 0400, deadline_batching_show},
 	{"starved", 0400, deadline_starved_show},
-	{"async_depth", 0400, dd_async_depth_show},
 	{"dispatch0", 0400, .seq_ops = &deadline_dispatch0_seq_ops},
 	{"dispatch1", 0400, .seq_ops = &deadline_dispatch1_seq_ops},
 	{"dispatch2", 0400, .seq_ops = &deadline_dispatch2_seq_ops},
@@ -1043,7 +1021,6 @@  static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = {
 
 static struct elevator_type mq_deadline = {
 	.ops = {
-		.depth_updated		= dd_depth_updated,
 		.limit_depth		= dd_limit_depth,
 		.insert_requests	= dd_insert_requests,
 		.dispatch_request	= dd_dispatch_request,
@@ -1058,7 +1035,7 @@  static struct elevator_type mq_deadline = {
 		.has_work		= dd_has_work,
 		.init_sched		= dd_init_sched,
 		.exit_sched		= dd_exit_sched,
-		.init_hctx		= dd_init_hctx,
+		.async_depth_updated	= dd_async_depth_updated,
 	},
 
 #ifdef CONFIG_BLK_DEBUG_FS