From: Yu Kuai <yukuai3@xxxxxxxxxx>
This helper only support to allocate the default number of requests,
add a new parameter to support specific number of requests.
Prepare to fix potential deadlock in the case nr_requests grow.
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Reviewed-by: Nilay Shroff <nilay@xxxxxxxxxxxxx>
---
block/blk-mq-sched.c | 14 +++++---------
block/blk-mq-sched.h | 2 +-
block/blk-mq.h | 11 +++++++++++
block/elevator.c | 3 ++-
4 files changed, 19 insertions(+), 11 deletions(-)
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index e2ce4a28e6c9..d06bb137a743 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -454,7 +454,7 @@ void blk_mq_free_sched_tags_batch(struct xarray *et_table,
}
struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set,
- unsigned int nr_hw_queues)
+ unsigned int nr_hw_queues, unsigned int nr_requests)
{
unsigned int nr_tags;
int i;
@@ -470,13 +470,8 @@ struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set,
nr_tags * sizeof(struct blk_mq_tags *), gfp);
if (!et)
return NULL;
- /*
- * Default to double of smaller one between hw queue_depth and
- * 128, since we don't split into sync/async like the old code
- * did. Additionally, this is a per-hw queue depth.
- */
- et->nr_requests = 2 * min_t(unsigned int, set->queue_depth,
- BLKDEV_DEFAULT_RQ);
+
+ et->nr_requests = nr_requests;
et->nr_hw_queues = nr_hw_queues;
if (blk_mq_is_shared_tags(set->flags)) {
@@ -521,7 +516,8 @@ int blk_mq_alloc_sched_tags_batch(struct xarray *et_table,
* concurrently.
*/
if (q->elevator) {
- et = blk_mq_alloc_sched_tags(set, nr_hw_queues);
+ et = blk_mq_alloc_sched_tags(set, nr_hw_queues,
+ blk_mq_default_nr_requests(set));
if (!et)
goto out_unwind;
if (xa_insert(et_table, q->id, et, gfp))
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index fe83187f41db..8e21a6b1415d 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -24,7 +24,7 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e);
void blk_mq_sched_free_rqs(struct request_queue *q);
struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set,
- unsigned int nr_hw_queues);
+ unsigned int nr_hw_queues, unsigned int nr_requests);
int blk_mq_alloc_sched_tags_batch(struct xarray *et_table,
struct blk_mq_tag_set *set, unsigned int nr_hw_queues);
void blk_mq_free_sched_tags(struct elevator_tags *et,
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 5d42c7d3a952..3a1d4c37d1bc 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -109,6 +109,17 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(blk_opf_t opf,
return ctx->hctxs[blk_mq_get_hctx_type(opf)];
}
+/*
+ * Default to double of smaller one between hw queue_depth and
+ * 128, since we don't split into sync/async like the old code
+ * did. Additionally, this is a per-hw queue depth.
+ */
+static inline unsigned int blk_mq_default_nr_requests(
+ struct blk_mq_tag_set *set)
+{
+ return 2 * min_t(unsigned int, set->queue_depth, BLKDEV_DEFAULT_RQ);
+}
+
/*
* sysfs helpers
*/
diff --git a/block/elevator.c b/block/elevator.c
index fe96c6f4753c..e2ebfbf107b3 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -669,7 +669,8 @@ static int elevator_change(struct request_queue *q, struct elv_change_ctx *ctx)
lockdep_assert_held(&set->update_nr_hwq_lock);
if (strncmp(ctx->name, "none", 4)) {
- ctx->et = blk_mq_alloc_sched_tags(set, set->nr_hw_queues);
+ ctx->et = blk_mq_alloc_sched_tags(set, set->nr_hw_queues,
+ blk_mq_default_nr_requests(set));
if (!ctx->et)
return -ENOMEM;
}
--
2.39.2
