Prepare to support per-request-queue dispatch list,
so introduce dispatch lock and list for avoiding to
do runtime check.
Signed-off-by: Ming Lei <ming....@redhat.com>
---
block/blk-mq-debugfs.c | 10 +++++-----
block/blk-mq-sched.c | 2 +-
block/blk-mq.c | 7 +++++--
block/blk-mq.h | 26 +++++++++++++-------------
include/linux/blk-mq.h | 3 +++
5 files changed, 27 insertions(+), 21 deletions(-)
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index febcaa7bfc82..734e478a0395 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -371,23 +371,23 @@ static void *hctx_dispatch_start(struct seq_file *m,
loff_t *pos)
{
struct blk_mq_hw_ctx *hctx = m->private;
- spin_lock(&hctx->lock);
- return seq_list_start(&hctx->dispatch, *pos);
+ spin_lock(hctx->dispatch_lock);
+ return seq_list_start(hctx->dispatch_list, *pos);
}
static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
{
struct blk_mq_hw_ctx *hctx = m->private;
- return seq_list_next(v, &hctx->dispatch, pos);
+ return seq_list_next(v, hctx->dispatch_list, pos);
}
static void hctx_dispatch_stop(struct seq_file *m, void *v)
- __releases(&hctx->lock)
+ __releases(hctx->dispatch_lock)
{
struct blk_mq_hw_ctx *hctx = m->private;
- spin_unlock(&hctx->lock);
+ spin_unlock(hctx->dispatch_lock);
}
static const struct seq_operations hctx_dispatch_seq_ops = {
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 5d435f01ecc8..53d6d5acd71c 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -176,7 +176,7 @@ void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx
*hctx)
* too small, no need to worry about performance
* effect.
*/
- if (list_empty_careful(&hctx->dispatch))
+ if (list_empty_careful(hctx->dispatch_list))
blk_mq_hctx_clear_dispatch_busy(hctx);
}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2392a813f5ee..86e4bb44f054 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1928,8 +1928,11 @@ static void blk_mq_exit_hw_queues(struct request_queue
*q,
static void blk_mq_init_dispatch(struct request_queue *q,
struct blk_mq_hw_ctx *hctx)
{
- spin_lock_init(&hctx->lock);
- INIT_LIST_HEAD(&hctx->dispatch);
+ hctx->dispatch_lock = &hctx->lock;
+ hctx->dispatch_list = &hctx->dispatch;
+
+ spin_lock_init(hctx->dispatch_lock);
+ INIT_LIST_HEAD(hctx->dispatch_list);
}
static int blk_mq_init_hctx(struct request_queue *q,
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 7f0d35ca5fea..474e1c2aa8c4 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -153,42 +153,42 @@ static inline void blk_mq_hctx_clear_dispatch_busy(struct
blk_mq_hw_ctx *hctx)
static inline bool blk_mq_has_dispatch_rqs(struct blk_mq_hw_ctx *hctx)
{
- return !list_empty_careful(&hctx->dispatch);
+ return !list_empty_careful(hctx->dispatch_list);
}
static inline void blk_mq_add_rq_to_dispatch(struct blk_mq_hw_ctx *hctx,
struct request *rq)
{
- spin_lock(&hctx->lock);
- list_add(&rq->queuelist, &hctx->dispatch);
+ spin_lock(hctx->dispatch_lock);
+ list_add(&rq->queuelist, hctx->dispatch_list);
blk_mq_hctx_set_dispatch_busy(hctx);
- spin_unlock(&hctx->lock);
+ spin_unlock(hctx->dispatch_lock);
}
static inline void blk_mq_add_list_to_dispatch(struct blk_mq_hw_ctx *hctx,
struct list_head *list)
{
- spin_lock(&hctx->lock);
- list_splice_init(list, &hctx->dispatch);
+ spin_lock(hctx->dispatch_lock);
+ list_splice_init(list, hctx->dispatch_list);
blk_mq_hctx_set_dispatch_busy(hctx);
- spin_unlock(&hctx->lock);
+ spin_unlock(hctx->dispatch_lock);
}
static inline void blk_mq_add_list_to_dispatch_tail(struct blk_mq_hw_ctx *hctx,
struct list_head *list)
{
- spin_lock(&hctx->lock);
- list_splice_tail_init(list, &hctx->dispatch);
+ spin_lock(hctx->dispatch_lock);
+ list_splice_tail_init(list, hctx->dispatch_list);
blk_mq_hctx_set_dispatch_busy(hctx);
- spin_unlock(&hctx->lock);
+ spin_unlock(hctx->dispatch_lock);
}
static inline void blk_mq_take_list_from_dispatch(struct blk_mq_hw_ctx *hctx,
struct list_head *list)
{
- spin_lock(&hctx->lock);
- list_splice_init(&hctx->dispatch, list);
- spin_unlock(&hctx->lock);
+ spin_lock(hctx->dispatch_lock);
+ list_splice_init(hctx->dispatch_list, list);
+ spin_unlock(hctx->dispatch_lock);
}
#endif
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 1197e5dee015..5c316e9e03a4 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -22,6 +22,9 @@ struct blk_mq_hw_ctx {
unsigned long flags; /* BLK_MQ_F_* flags */
+ spinlock_t *dispatch_lock;
+ struct list_head *dispatch_list;
+
void *sched_data;
struct request_queue *queue;
struct blk_flush_queue *fq;
--
2.9.4
