On 26/09/2021 04:25, Ming Lei wrote:

quoted

c

@@ -27,10 +27,11 @@ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
  	if (blk_mq_is_sbitmap_shared(hctx->flags)) {
  		struct request_queue *q = hctx->queue;
  		struct blk_mq_tag_set *set = q->tag_set;
+		struct blk_mq_tags *tags = set->shared_sbitmap_tags;

The local variable of 'set' can be removed and just retrieve 'tags' from
hctx->tags.

quoted

  
  		if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags) &&
  		    !test_and_set_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
-			atomic_inc(&set->active_queues_shared_sbitmap);
+			atomic_inc(&tags->active_queues);
  	} else {
  		if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) &&
  		    !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))

@@ -61,10 +62,12 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
  	struct blk_mq_tag_set *set = q->tag_set;
  
  	if (blk_mq_is_sbitmap_shared(hctx->flags)) {
+		struct blk_mq_tags *tags = set->shared_sbitmap_tags;
+

Same with above.

ok

quoted

  		if (!test_and_clear_bit(QUEUE_FLAG_HCTX_ACTIVE,
  					&q->queue_flags))
  			return;
-		atomic_dec(&set->active_queues_shared_sbitmap);
+		atomic_dec(&tags->active_queues);
  	} else {
  		if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
  			return;

@@ -510,38 +513,10 @@ static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
  	return 0;
  }

...

quoted

-	struct sbitmap_queue	__bitmap_tags;
-	struct sbitmap_queue	__breserved_tags;
  	struct blk_mq_tags	**tags;
  
+	struct blk_mq_tags	*shared_sbitmap_tags;
+
  	struct mutex		tag_list_lock;
  	struct list_head	tag_list;
  };

@@ -432,6 +429,8 @@ enum {
  	((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
  		<< BLK_MQ_F_ALLOC_POLICY_START_BIT)
  
+#define BLK_MQ_NO_HCTX_IDX	(-1U)
+
  struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, void *queuedata,
  		struct lock_class_key *lkclass);
  #define blk_mq_alloc_disk(set, queuedata)				\

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 4baf9435232d..17e50e5ef47b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h

@@ -459,8 +459,7 @@ struct request_queue {
  
  	atomic_t		nr_active_requests_shared_sbitmap;
  
-	struct sbitmap_queue	sched_bitmap_tags;
-	struct sbitmap_queue	sched_breserved_tags;
+	struct blk_mq_tags	*shared_sbitmap_tags;

Maybe better with shared_sched_sbitmap_tags or sched_sbitmap_tags?

Yeah, I suppose I should add "sched" to the name, as before.

BTW, Do you think that I should just change shared_sbitmap -> 
shared_tags naming now globally? I'm thinking now that I should...

Thanks,
John