All requests in the 'list' of blk_mq_dispatch_rq_list belong to same
hctx, so it is better to pass hctx instead of request queue, because
blk-mq's dispatch target is hctx instead of request queue.
Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
Cc: Baolin Wang <baolin.wang7@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Tested-by: Baolin Wang <baolin.wang7@xxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-mq-sched.c | 14 ++++++--------
block/blk-mq.c | 6 +++---
block/blk-mq.h | 2 +-
3 files changed, 10 insertions(+), 12 deletions(-)
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index a31e281e9d31..632c6f8b63f7 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -96,10 +96,9 @@ static int blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx)
struct elevator_queue *e = q->elevator;
LIST_HEAD(rq_list);
int ret = 0;
+ struct request *rq;
do {
- struct request *rq;
-
if (e->type->ops.has_work && !e->type->ops.has_work(hctx))
break;
@@ -131,7 +130,7 @@ static int blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx)
* in blk_mq_dispatch_rq_list().
*/
list_add(&rq->queuelist, &rq_list);
- } while (blk_mq_dispatch_rq_list(q, &rq_list, true));
+ } while (blk_mq_dispatch_rq_list(rq->mq_hctx, &rq_list, true));
return ret;
}
@@ -161,10 +160,9 @@ static int blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx)
LIST_HEAD(rq_list);
struct blk_mq_ctx *ctx = READ_ONCE(hctx->dispatch_from);
int ret = 0;
+ struct request *rq;
do {
- struct request *rq;
-
if (!list_empty_careful(&hctx->dispatch)) {
ret = -EAGAIN;
break;
@@ -200,7 +198,7 @@ static int blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx)
/* round robin for fair dispatch */
ctx = blk_mq_next_ctx(hctx, rq->mq_ctx);
- } while (blk_mq_dispatch_rq_list(q, &rq_list, true));
+ } while (blk_mq_dispatch_rq_list(rq->mq_hctx, &rq_list, true));
WRITE_ONCE(hctx->dispatch_from, ctx);
return ret;
@@ -240,7 +238,7 @@ static int __blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
*/
if (!list_empty(&rq_list)) {
blk_mq_sched_mark_restart_hctx(hctx);
- if (blk_mq_dispatch_rq_list(q, &rq_list, false)) {
+ if (blk_mq_dispatch_rq_list(hctx, &rq_list, false)) {
if (has_sched_dispatch)
ret = blk_mq_do_dispatch_sched(hctx);
else
@@ -253,7 +251,7 @@ static int __blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
ret = blk_mq_do_dispatch_ctx(hctx);
} else {
blk_mq_flush_busy_ctxs(hctx, &rq_list);
- blk_mq_dispatch_rq_list(q, &rq_list, false);
+ blk_mq_dispatch_rq_list(hctx, &rq_list, false);
}
return ret;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index bcbf49bd7ebe..723bc39507fe 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1236,10 +1236,10 @@ static void blk_mq_handle_zone_resource(struct request *rq,
/*
* Returns true if we did some work AND can potentially do more.
*/
-bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
+bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list,
bool got_budget)
{
- struct blk_mq_hw_ctx *hctx;
+ struct request_queue *q = hctx->queue;
struct request *rq, *nxt;
bool no_tag = false;
int errors, queued;
@@ -1261,7 +1261,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
rq = list_first_entry(list, struct request, queuelist);
- hctx = rq->mq_hctx;
+ WARN_ON_ONCE(hctx != rq->mq_hctx);
if (!got_budget && !blk_mq_get_dispatch_budget(q)) {
blk_mq_put_driver_tag(rq);
no_budget_avail = true;
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 21d877105224..d2d737b16e0e 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -40,7 +40,7 @@ struct blk_mq_ctx {
void blk_mq_exit_queue(struct request_queue *q);
int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
void blk_mq_wake_waiters(struct request_queue *q);
-bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
+bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *, bool);
void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
bool kick_requeue_list);
void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
--
2.25.2
