From: Yu Kuai <yukuai3@xxxxxxxxxx>
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@xxxxxxxxxx>
---
block/mq-deadline.c | 43 ++++++++++---------------------------------
1 file changed, 10 insertions(+), 33 deletions(-)
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
--
2.39.2
