From: Jens Axboe <axboe@fb.com>
Date: Mon, 19 May 2014 17:52:35 +0000 (-0600)
Subject: Merge branch 'for-3.16/blk-mq-tagging' into for-3.16/core
X-Git-Tag: firefly_0821_release~176^2~3465^2~52^2~36
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=39a9f97e5ea99e048c4980c23cf197f6e77995cb;p=firefly-linux-kernel-4.4.55.git

Merge branch 'for-3.16/blk-mq-tagging' into for-3.16/core

Signed-off-by: Jens Axboe <axboe@fb.com>

Conflicts:
	block/blk-mq-tag.c
---

39a9f97e5ea99e048c4980c23cf197f6e77995cb
diff --cc block/blk-mq-tag.c
index 03ce6a11ba79,c80086c9c064..e6b3fbae9862
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@@ -40,7 -39,85 +39,85 @@@ bool blk_mq_has_free_tags(struct blk_mq
  	return bt_has_free_tags(&tags->bitmap_tags);
  }
  
+ static inline void bt_index_inc(unsigned int *index)
+ {
+ 	*index = (*index + 1) & (BT_WAIT_QUEUES - 1);
+ }
+ 
+ /*
+  * If a previously inactive queue goes active, bump the active user count.
+  */
+ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
+ {
+ 	if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) &&
+ 	    !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
+ 		atomic_inc(&hctx->tags->active_queues);
+ 
+ 	return true;
+ }
+ 
+ /*
+  * If a previously busy queue goes inactive, potential waiters could now
+  * be allowed to queue. Wake them up and check.
+  */
+ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
+ {
+ 	struct blk_mq_tags *tags = hctx->tags;
+ 	struct blk_mq_bitmap_tags *bt;
+ 	int i, wake_index;
+ 
+ 	if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
+ 		return;
+ 
+ 	atomic_dec(&tags->active_queues);
+ 
+ 	/*
+ 	 * Will only throttle depth on non-reserved tags
+ 	 */
+ 	bt = &tags->bitmap_tags;
+ 	wake_index = bt->wake_index;
+ 	for (i = 0; i < BT_WAIT_QUEUES; i++) {
+ 		struct bt_wait_state *bs = &bt->bs[wake_index];
+ 
+ 		if (waitqueue_active(&bs->wait))
+ 			wake_up(&bs->wait);
+ 
+ 		bt_index_inc(&wake_index);
+ 	}
+ }
+ 
+ /*
+  * For shared tag users, we track the number of currently active users
+  * and attempt to provide a fair share of the tag depth for each of them.
+  */
+ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
+ 				  struct blk_mq_bitmap_tags *bt)
+ {
+ 	unsigned int depth, users;
+ 
+ 	if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_SHARED))
+ 		return true;
+ 	if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
+ 		return true;
+ 
+ 	/*
+ 	 * Don't try dividing an ant
+ 	 */
+ 	if (bt->depth == 1)
+ 		return true;
+ 
+ 	users = atomic_read(&hctx->tags->active_queues);
+ 	if (!users)
+ 		return true;
+ 
+ 	/*
+ 	 * Allow at least some tags
+ 	 */
+ 	depth = max((bt->depth + users - 1) / users, 4U);
+ 	return atomic_read(&hctx->nr_active) < depth;
+ }
+ 
 -static int __bt_get_word(struct blk_mq_bitmap *bm, unsigned int last_tag)
 +static int __bt_get_word(struct blk_align_bitmap *bm, unsigned int last_tag)
  {
  	int tag, org_last_tag, end;
  
diff --cc block/blk-mq.c
index e862c4408427,3c4f1fceef8e..0fbef7e9bef1
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@@ -1605,7 -1611,10 +1673,9 @@@ void blk_mq_free_queue(struct request_q
  	struct blk_mq_hw_ctx *hctx;
  	int i;
  
+ 	blk_mq_del_queue_tag_set(q);
+ 
  	queue_for_each_hw_ctx(q, hctx, i) {
 -		kfree(hctx->ctx_map);
  		kfree(hctx->ctxs);
  		blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
  		if (q->mq_ops->exit_hctx)