diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 5b675b226f64..014984d199e7 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -573,6 +573,57 @@ static inline unsigned int bfq_wr_duration(struct bfq_data *bfqd)
 	return dur;
 }
 
+static inline unsigned
+bfq_bfqq_cooperations(struct bfq_queue *bfqq)
+{
+	return bfqq->bic ? bfqq->bic->cooperations : 0;
+}
+
+static inline void
+bfq_bfqq_resume_state(struct bfq_queue *bfqq, struct bfq_io_cq *bic)
+{
+	if (bic->saved_idle_window)
+		bfq_mark_bfqq_idle_window(bfqq);
+	else
+		bfq_clear_bfqq_idle_window(bfqq);
+	if (bic->saved_IO_bound)
+		bfq_mark_bfqq_IO_bound(bfqq);
+	else
+		bfq_clear_bfqq_IO_bound(bfqq);
+	/* Assuming that the flag in_large_burst is already correctly set */
+	if (bic->wr_time_left && bfqq->bfqd->low_latency &&
+	    !bfq_bfqq_in_large_burst(bfqq) &&
+	    bic->cooperations < bfqq->bfqd->bfq_coop_thresh) {
+		/*
+		 * Start a weight raising period with the duration given by
+		 * the raising_time_left snapshot.
+		 */
+		if (bfq_bfqq_busy(bfqq))
+			bfqq->bfqd->wr_busy_queues++;
+		bfqq->wr_coeff = bfqq->bfqd->bfq_wr_coeff;
+		bfqq->wr_cur_max_time = bic->wr_time_left;
+		bfqq->last_wr_start_finish = jiffies;
+		bfqq->entity.ioprio_changed = 1;
+	}
+	/*
+	 * Clear wr_time_left to prevent bfq_bfqq_save_state() from
+	 * getting confused about the queue's need of a weight-raising
+	 * period.
+	 */
+	bic->wr_time_left = 0;
+}
+
+/* Must be called with the queue_lock held. */
+static int bfqq_process_refs(struct bfq_queue *bfqq)
+{
+	int process_refs, io_refs;
+
+	io_refs = bfqq->allocated[READ] + bfqq->allocated[WRITE];
+	process_refs = atomic_read(&bfqq->ref) - io_refs - bfqq->entity.on_st;
+	BUG_ON(process_refs < 0);
+	return process_refs;
+}
+
 /* Empty burst list and add just bfqq (see comments to bfq_handle_burst) */
 static inline void bfq_reset_burst_list(struct bfq_data *bfqd,
 					struct bfq_queue *bfqq)
@@ -817,7 +868,7 @@ static void bfq_add_request(struct request *rq)
 		bfq_rq_pos_tree_add(bfqd, bfqq);
 
 	if (!bfq_bfqq_busy(bfqq)) {
-		bool soft_rt,
+		bool soft_rt, coop_or_in_burst,
 		     idle_for_long_time = time_is_before_jiffies(
 						bfqq->budget_timeout +
 						bfqd->bfq_wr_min_idle_time);
@@ -841,11 +892,12 @@ static void bfq_add_request(struct request *rq)
 				bfqd->last_ins_in_burst = jiffies;
 		}
 
+		coop_or_in_burst = bfq_bfqq_in_large_burst(bfqq) ||
+			bfq_bfqq_cooperations(bfqq) >= bfqd->bfq_coop_thresh;
 		soft_rt = bfqd->bfq_wr_max_softrt_rate > 0 &&
-			!bfq_bfqq_in_large_burst(bfqq) &&
+			!coop_or_in_burst &&
 			time_is_before_jiffies(bfqq->soft_rt_next_start);
-		interactive = !bfq_bfqq_in_large_burst(bfqq) &&
-			      idle_for_long_time;
+		interactive = !coop_or_in_burst && idle_for_long_time;
 		entity->budget = max_t(unsigned long, bfqq->max_budget,
 				       bfq_serv_to_charge(next_rq, bfqq));
 
@@ -864,11 +916,20 @@ static void bfq_add_request(struct request *rq)
 		if (!bfqd->low_latency)
 			goto add_bfqq_busy;
 
+		if (bfq_bfqq_just_split(bfqq))
+			goto set_ioprio_changed;
+
 		/*
-		 * If the queue is not being boosted and has been idle
-		 * for enough time, start a weight-raising period
+		 * If the queue:
+		 * - is not being boosted,
+		 * - has been idle for enough time,
+		 * - is not a sync queue or is linked to a bfq_io_cq (it is
+		 *   shared "for its nature" or it is not shared and its
+		 *   requests have not been redirected to a shared queue)
+		 * start a weight-raising period.
 		 */
-		if (old_wr_coeff == 1 && (interactive || soft_rt)) {
+		if (old_wr_coeff == 1 && (interactive || soft_rt) &&
+		    (!bfq_bfqq_sync(bfqq) || bfqq->bic != NULL)) {
 			bfqq->wr_coeff = bfqd->bfq_wr_coeff;
 			if (interactive)
 				bfqq->wr_cur_max_time = bfq_wr_duration(bfqd);
@@ -882,7 +943,7 @@ static void bfq_add_request(struct request *rq)
 		} else if (old_wr_coeff > 1) {
 			if (interactive)
 				bfqq->wr_cur_max_time = bfq_wr_duration(bfqd);
-			else if (bfq_bfqq_in_large_burst(bfqq) ||
+			else if (coop_or_in_burst ||
 				 (bfqq->wr_cur_max_time ==
 				  bfqd->bfq_wr_rt_max_time &&
 				  !soft_rt)) {
@@ -901,18 +962,18 @@ static void bfq_add_request(struct request *rq)
 				/*
 				 *
 				 * The remaining weight-raising time is lower
-				 * than bfqd->bfq_wr_rt_max_time, which
-				 * means that the application is enjoying
-				 * weight raising either because deemed soft-
-				 * rt in the near past, or because deemed
-				 * interactive a long ago. In both cases,
-				 * resetting now the current remaining weight-
-				 * raising time for the application to the
-				 * weight-raising duration for soft rt
-				 * applications would not cause any latency
-				 * increase for the application (as the new
-				 * duration would be higher than the remaining
-				 * time).
+				 * than bfqd->bfq_wr_rt_max_time, which means
+				 * that the application is enjoying weight
+				 * raising either because deemed soft-rt in
+				 * the near past, or because deemed interactive
+				 * a long ago.
+				 * In both cases, resetting now the current
+				 * remaining weight-raising time for the
+				 * application to the weight-raising duration
+				 * for soft rt applications would not cause any
+				 * latency increase for the application (as the
+				 * new duration would be higher than the
+				 * remaining time).
 				 *
 				 * In addition, the application is now meeting
 				 * the requirements for being deemed soft rt.
@@ -947,6 +1008,7 @@ static void bfq_add_request(struct request *rq)
 					bfqd->bfq_wr_rt_max_time;
 			}
 		}
+set_ioprio_changed:
 		if (old_wr_coeff != bfqq->wr_coeff)
 			entity->ioprio_changed = 1;
 add_bfqq_busy:
@@ -1167,12 +1229,367 @@ static void bfq_end_wr(struct bfq_data *bfqd)
 	spin_unlock_irq(bfqd->queue->queue_lock);
 }
 
+static inline sector_t bfq_io_struct_pos(void *io_struct, bool request)
+{
+	if (request)
+		return blk_rq_pos(io_struct);
+	else
+		return ((struct bio *)io_struct)->bi_sector;
+}
+
+static inline sector_t bfq_dist_from(sector_t pos1,
+				     sector_t pos2)
+{
+	if (pos1 >= pos2)
+		return pos1 - pos2;
+	else
+		return pos2 - pos1;
+}
+
+static inline int bfq_rq_close_to_sector(void *io_struct, bool request,
+					 sector_t sector)
+{
+	return bfq_dist_from(bfq_io_struct_pos(io_struct, request), sector) <=
+	       BFQQ_SEEK_THR;
+}
+
+static struct bfq_queue *bfqq_close(struct bfq_data *bfqd, sector_t sector)
+{
+	struct rb_root *root = &bfqd->rq_pos_tree;
+	struct rb_node *parent, *node;
+	struct bfq_queue *__bfqq;
+
+	if (RB_EMPTY_ROOT(root))
+		return NULL;
+
+	/*
+	 * First, if we find a request starting at the end of the last
+	 * request, choose it.
+	 */
+	__bfqq = bfq_rq_pos_tree_lookup(bfqd, root, sector, &parent, NULL);
+	if (__bfqq != NULL)
+		return __bfqq;
+
+	/*
+	 * If the exact sector wasn't found, the parent of the NULL leaf
+	 * will contain the closest sector (rq_pos_tree sorted by
+	 * next_request position).
+	 */
+	__bfqq = rb_entry(parent, struct bfq_queue, pos_node);
+	if (bfq_rq_close_to_sector(__bfqq->next_rq, true, sector))
+		return __bfqq;
+
+	if (blk_rq_pos(__bfqq->next_rq) < sector)
+		node = rb_next(&__bfqq->pos_node);
+	else
+		node = rb_prev(&__bfqq->pos_node);
+	if (node == NULL)
+		return NULL;
+
+	__bfqq = rb_entry(node, struct bfq_queue, pos_node);
+	if (bfq_rq_close_to_sector(__bfqq->next_rq, true, sector))
+		return __bfqq;
+
+	return NULL;
+}
+
+/*
+ * bfqd - obvious
+ * cur_bfqq - passed in so that we don't decide that the current queue
+ *            is closely cooperating with itself
+ * sector - used as a reference point to search for a close queue
+ */
+static struct bfq_queue *bfq_close_cooperator(struct bfq_data *bfqd,
+					      struct bfq_queue *cur_bfqq,
+					      sector_t sector)
+{
+	struct bfq_queue *bfqq;
+
+	if (bfq_class_idle(cur_bfqq))
+		return NULL;
+	if (!bfq_bfqq_sync(cur_bfqq))
+		return NULL;
+	if (BFQQ_SEEKY(cur_bfqq))
+		return NULL;
+
+	/* If device has only one backlogged bfq_queue, don't search. */
+	if (bfqd->busy_queues == 1)
+		return NULL;
+
+	/*
+	 * We should notice if some of the queues are cooperating, e.g.
+	 * working closely on the same area of the disk. In that case,
+	 * we can group them together and don't waste time idling.
+	 */
+	bfqq = bfqq_close(bfqd, sector);
+	if (bfqq == NULL || bfqq == cur_bfqq)
+		return NULL;
+
+	/*
+	 * Do not merge queues from different bfq_groups.
+	*/
+	if (bfqq->entity.parent != cur_bfqq->entity.parent)
+		return NULL;
+
+	/*
+	 * It only makes sense to merge sync queues.
+	 */
+	if (!bfq_bfqq_sync(bfqq))
+		return NULL;
+	if (BFQQ_SEEKY(bfqq))
+		return NULL;
+
+	/*
+	 * Do not merge queues of different priority classes.
+	 */
+	if (bfq_class_rt(bfqq) != bfq_class_rt(cur_bfqq))
+		return NULL;
+
+	return bfqq;
+}
+
+static struct bfq_queue *
+bfq_setup_merge(struct bfq_queue *bfqq, struct bfq_queue *new_bfqq)
+{
+	int process_refs, new_process_refs;
+	struct bfq_queue *__bfqq;
+
+	/*
+	 * If there are no process references on the new_bfqq, then it is
+	 * unsafe to follow the ->new_bfqq chain as other bfqq's in the chain
+	 * may have dropped their last reference (not just their last process
+	 * reference).
+	 */
+	if (!bfqq_process_refs(new_bfqq))
+		return NULL;
+
+	/* Avoid a circular list and skip interim queue merges. */
+	while ((__bfqq = new_bfqq->new_bfqq)) {
+		if (__bfqq == bfqq)
+			return NULL;
+		new_bfqq = __bfqq;
+	}
+
+	process_refs = bfqq_process_refs(bfqq);
+	new_process_refs = bfqq_process_refs(new_bfqq);
+	/*
+	 * If the process for the bfqq has gone away, there is no
+	 * sense in merging the queues.
+	 */
+	if (process_refs == 0 || new_process_refs == 0)
+		return NULL;
+
+	bfq_log_bfqq(bfqq->bfqd, bfqq, "scheduling merge with queue %d",
+		new_bfqq->pid);
+
+	/*
+	 * Merging is just a redirection: the requests of the process
+	 * owning one of the two queues are redirected to the other queue.
+	 * The latter queue, in its turn, is set as shared if this is the
+	 * first time that the requests of some process are redirected to
+	 * it.
+	 *
+	 * We redirect bfqq to new_bfqq and not the opposite, because we
+	 * are in the context of the process owning bfqq, hence we have
+	 * the io_cq of this process. So we can immediately configure this
+	 * io_cq to redirect the requests of the process to new_bfqq.
+	 *
+	 * NOTE, even if new_bfqq coincides with the in-service queue, the
+	 * io_cq of new_bfqq is not available, because, if the in-service
+	 * queue is shared, bfqd->in_service_bic may not point to the
+	 * io_cq of the in-service queue.
+	 * Redirecting the requests of the process owning bfqq to the
+	 * currently in-service queue is in any case the best option, as
+	 * we feed the in-service queue with new requests close to the
+	 * last request served and, by doing so, hopefully increase the
+	 * throughput.
+	 */
+	bfqq->new_bfqq = new_bfqq;
+	atomic_add(process_refs, &new_bfqq->ref);
+	return new_bfqq;
+}
+
+/*
+ * Attempt to schedule a merge of bfqq with the currently in-service queue
+ * or with a close queue among the scheduled queues.
+ * Return NULL if no merge was scheduled, a pointer to the shared bfq_queue
+ * structure otherwise.
+ *
+ * The OOM queue is not allowed to participate to cooperation: in fact, since
+ * the requests temporarily redirected to the OOM queue could be redirected
+ * again to dedicated queues at any time, the state needed to correctly
+ * handle merging with the OOM queue would be quite complex and expensive
+ * to maintain. Besides, in such a critical condition as an out of memory,
+ * the benefits of queue merging may be little relevant, or even negligible.
+ */
+static struct bfq_queue *
+bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+		     void *io_struct, bool request)
+{
+	struct bfq_queue *in_service_bfqq, *new_bfqq;
+
+	if (bfqq->new_bfqq)
+		return bfqq->new_bfqq;
+
+	if (!io_struct || unlikely(bfqq == &bfqd->oom_bfqq))
+		return NULL;
+
+	in_service_bfqq = bfqd->in_service_queue;
+
+	if (in_service_bfqq == NULL || in_service_bfqq == bfqq ||
+	    !bfqd->in_service_bic ||
+	    unlikely(in_service_bfqq == &bfqd->oom_bfqq))
+		goto check_scheduled;
+
+	if (bfq_class_idle(in_service_bfqq) || bfq_class_idle(bfqq))
+		goto check_scheduled;
+
+	if (bfq_class_rt(in_service_bfqq) != bfq_class_rt(bfqq))
+		goto check_scheduled;
+
+	if (in_service_bfqq->entity.parent != bfqq->entity.parent)
+		goto check_scheduled;
+
+	if (bfq_rq_close_to_sector(io_struct, request, bfqd->last_position) &&
+	    bfq_bfqq_sync(in_service_bfqq) && bfq_bfqq_sync(bfqq)) {
+		new_bfqq = bfq_setup_merge(bfqq, in_service_bfqq);
+		if (new_bfqq != NULL)
+			return new_bfqq; /* Merge with in-service queue */
+	}
+
+	/*
+	 * Check whether there is a cooperator among currently scheduled
+	 * queues. The only thing we need is that the bio/request is not
+	 * NULL, as we need it to establish whether a cooperator exists.
+	 */
+check_scheduled:
+	new_bfqq = bfq_close_cooperator(bfqd, bfqq,
+					bfq_io_struct_pos(io_struct, request));
+	if (new_bfqq && likely(new_bfqq != &bfqd->oom_bfqq))
+		return bfq_setup_merge(bfqq, new_bfqq);
+
+	return NULL;
+}
+
+static inline void
+bfq_bfqq_save_state(struct bfq_queue *bfqq)
+{
+	/*
+	 * If bfqq->bic == NULL, the queue is already shared or its requests
+	 * have already been redirected to a shared queue; both idle window
+	 * and weight raising state have already been saved. Do nothing.
+	 */
+	if (bfqq->bic == NULL)
+		return;
+	if (bfqq->bic->wr_time_left)
+		/*
+		 * This is the queue of a just-started process, and would
+		 * deserve weight raising: we set wr_time_left to the full
+		 * weight-raising duration to trigger weight-raising when
+		 * and if the queue is split and the first request of the
+		 * queue is enqueued.
+		 */
+		bfqq->bic->wr_time_left = bfq_wr_duration(bfqq->bfqd);
+	else if (bfqq->wr_coeff > 1) {
+		unsigned long wr_duration =
+			jiffies - bfqq->last_wr_start_finish;
+		/*
+		 * It may happen that a queue's weight raising period lasts
+		 * longer than its wr_cur_max_time, as weight raising is
+		 * handled only when a request is enqueued or dispatched (it
+		 * does not use any timer). If the weight raising period is
+		 * about to end, don't save it.
+		 */
+		if (bfqq->wr_cur_max_time <= wr_duration)
+			bfqq->bic->wr_time_left = 0;
+		else
+			bfqq->bic->wr_time_left =
+				bfqq->wr_cur_max_time - wr_duration;
+		/*
+		 * The bfq_queue is becoming shared or the requests of the
+		 * process owning the queue are being redirected to a shared
+		 * queue. Stop the weight raising period of the queue, as in
+		 * both cases it should not be owned by an interactive or
+		 * soft real-time application.
+		 */
+		bfq_bfqq_end_wr(bfqq);
+	} else
+		bfqq->bic->wr_time_left = 0;
+	bfqq->bic->saved_idle_window = bfq_bfqq_idle_window(bfqq);
+	bfqq->bic->saved_IO_bound = bfq_bfqq_IO_bound(bfqq);
+	bfqq->bic->saved_in_large_burst = bfq_bfqq_in_large_burst(bfqq);
+	bfqq->bic->was_in_burst_list = !hlist_unhashed(&bfqq->burst_list_node);
+	bfqq->bic->cooperations++;
+	bfqq->bic->failed_cooperations = 0;
+}
+
+static inline void
+bfq_get_bic_reference(struct bfq_queue *bfqq)
+{
+	/*
+	 * If bfqq->bic has a non-NULL value, the bic to which it belongs
+	 * is about to begin using a shared bfq_queue.
+	 */
+	if (bfqq->bic)
+		atomic_long_inc(&bfqq->bic->icq.ioc->refcount);
+}
+
+static void
+bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic,
+		struct bfq_queue *bfqq, struct bfq_queue *new_bfqq)
+{
+	bfq_log_bfqq(bfqd, bfqq, "merging with queue %lu",
+		(long unsigned)new_bfqq->pid);
+	/* Save weight raising and idle window of the merged queues */
+	bfq_bfqq_save_state(bfqq);
+	bfq_bfqq_save_state(new_bfqq);
+	if (bfq_bfqq_IO_bound(bfqq))
+		bfq_mark_bfqq_IO_bound(new_bfqq);
+	bfq_clear_bfqq_IO_bound(bfqq);
+	/*
+	 * Grab a reference to the bic, to prevent it from being destroyed
+	 * before being possibly touched by a bfq_split_bfqq().
+	 */
+	bfq_get_bic_reference(bfqq);
+	bfq_get_bic_reference(new_bfqq);
+	/*
+	 * Merge queues (that is, let bic redirect its requests to new_bfqq)
+	 */
+	bic_set_bfqq(bic, new_bfqq, 1);
+	bfq_mark_bfqq_coop(new_bfqq);
+	/*
+	 * new_bfqq now belongs to at least two bics (it is a shared queue):
+	 * set new_bfqq->bic to NULL. bfqq either:
+	 * - does not belong to any bic any more, and hence bfqq->bic must
+	 *   be set to NULL, or
+	 * - is a queue whose owning bics have already been redirected to a
+	 *   different queue, hence the queue is destined to not belong to
+	 *   any bic soon and bfqq->bic is already NULL (therefore the next
+	 *   assignment causes no harm).
+	 */
+	new_bfqq->bic = NULL;
+	bfqq->bic = NULL;
+	bfq_put_queue(bfqq);
+}
+
+static inline void bfq_bfqq_increase_failed_cooperations(struct bfq_queue *bfqq)
+{
+	struct bfq_io_cq *bic = bfqq->bic;
+	struct bfq_data *bfqd = bfqq->bfqd;
+
+	if (bic && bfq_bfqq_cooperations(bfqq) >= bfqd->bfq_coop_thresh) {
+		bic->failed_cooperations++;
+		if (bic->failed_cooperations >= bfqd->bfq_failed_cooperations)
+			bic->cooperations = 0;
+	}
+}
+
 static int bfq_allow_merge(struct request_queue *q, struct request *rq,
 			   struct bio *bio)
 {
 	struct bfq_data *bfqd = q->elevator->elevator_data;
 	struct bfq_io_cq *bic;
-	struct bfq_queue *bfqq;
+	struct bfq_queue *bfqq, *new_bfqq;
 
 	/*
 	 * Disallow merge of a sync bio into an async request.
@@ -1190,6 +1607,24 @@ static int bfq_allow_merge(struct request_queue *q, struct request *rq,
 		return 0;
 
 	bfqq = bic_to_bfqq(bic, bfq_bio_sync(bio));
+	/*
+	 * We take advantage of this function to perform an early merge
+	 * of the queues of possible cooperating processes.
+	 */
+	if (bfqq != NULL) {
+		new_bfqq = bfq_setup_cooperator(bfqd, bfqq, bio, false);
+		if (new_bfqq != NULL) {
+			bfq_merge_bfqqs(bfqd, bic, bfqq, new_bfqq);
+			/*
+			 * If we get here, the bio will be queued in the
+			 * shared queue, i.e., new_bfqq, so use new_bfqq
+			 * to decide whether bio and rq can be merged.
+			 */
+			bfqq = new_bfqq;
+		} else
+			bfq_bfqq_increase_failed_cooperations(bfqq);
+	}
+
 	return bfqq == RQ_BFQQ(rq);
 }
 
@@ -1214,135 +1649,14 @@ static void __bfq_set_in_service_queue(struct bfq_data *bfqd,
 /*
  * Get and set a new queue for service.
  */
-static struct bfq_queue *bfq_set_in_service_queue(struct bfq_data *bfqd,
-						  struct bfq_queue *bfqq)
+static struct bfq_queue *bfq_set_in_service_queue(struct bfq_data *bfqd)
 {
-	if (!bfqq)
-		bfqq = bfq_get_next_queue(bfqd);
-	else
-		bfq_get_next_queue_forced(bfqd, bfqq);
+	struct bfq_queue *bfqq = bfq_get_next_queue(bfqd);
 
 	__bfq_set_in_service_queue(bfqd, bfqq);
 	return bfqq;
 }
 
-static inline sector_t bfq_dist_from_last(struct bfq_data *bfqd,
-					  struct request *rq)
-{
-	if (blk_rq_pos(rq) >= bfqd->last_position)
-		return blk_rq_pos(rq) - bfqd->last_position;
-	else
-		return bfqd->last_position - blk_rq_pos(rq);
-}
-
-/*
- * Return true if bfqq has no request pending and rq is close enough to
- * bfqd->last_position, or if rq is closer to bfqd->last_position than
- * bfqq->next_rq
- */
-static inline int bfq_rq_close(struct bfq_data *bfqd, struct request *rq)
-{
-	return bfq_dist_from_last(bfqd, rq) <= BFQQ_SEEK_THR;
-}
-
-static struct bfq_queue *bfqq_close(struct bfq_data *bfqd)
-{
-	struct rb_root *root = &bfqd->rq_pos_tree;
-	struct rb_node *parent, *node;
-	struct bfq_queue *__bfqq;
-	sector_t sector = bfqd->last_position;
-
-	if (RB_EMPTY_ROOT(root))
-		return NULL;
-
-	/*
-	 * First, if we find a request starting at the end of the last
-	 * request, choose it.
-	 */
-	__bfqq = bfq_rq_pos_tree_lookup(bfqd, root, sector, &parent, NULL);
-	if (__bfqq != NULL)
-		return __bfqq;
-
-	/*
-	 * If the exact sector wasn't found, the parent of the NULL leaf
-	 * will contain the closest sector (rq_pos_tree sorted by
-	 * next_request position).
-	 */
-	__bfqq = rb_entry(parent, struct bfq_queue, pos_node);
-	if (bfq_rq_close(bfqd, __bfqq->next_rq))
-		return __bfqq;
-
-	if (blk_rq_pos(__bfqq->next_rq) < sector)
-		node = rb_next(&__bfqq->pos_node);
-	else
-		node = rb_prev(&__bfqq->pos_node);
-	if (node == NULL)
-		return NULL;
-
-	__bfqq = rb_entry(node, struct bfq_queue, pos_node);
-	if (bfq_rq_close(bfqd, __bfqq->next_rq))
-		return __bfqq;
-
-	return NULL;
-}
-
-/*
- * bfqd - obvious
- * cur_bfqq - passed in so that we don't decide that the current queue
- *            is closely cooperating with itself.
- *
- * We are assuming that cur_bfqq has dispatched at least one request,
- * and that bfqd->last_position reflects a position on the disk associated
- * with the I/O issued by cur_bfqq.
- */
-static struct bfq_queue *bfq_close_cooperator(struct bfq_data *bfqd,
-					      struct bfq_queue *cur_bfqq)
-{
-	struct bfq_queue *bfqq;
-
-	if (bfq_class_idle(cur_bfqq))
-		return NULL;
-	if (!bfq_bfqq_sync(cur_bfqq))
-		return NULL;
-	if (BFQQ_SEEKY(cur_bfqq))
-		return NULL;
-
-	/* If device has only one backlogged bfq_queue, don't search. */
-	if (bfqd->busy_queues == 1)
-		return NULL;
-
-	/*
-	 * We should notice if some of the queues are cooperating, e.g.
-	 * working closely on the same area of the disk. In that case,
-	 * we can group them together and don't waste time idling.
-	 */
-	bfqq = bfqq_close(bfqd);
-	if (bfqq == NULL || bfqq == cur_bfqq)
-		return NULL;
-
-	/*
-	 * Do not merge queues from different bfq_groups.
-	*/
-	if (bfqq->entity.parent != cur_bfqq->entity.parent)
-		return NULL;
-
-	/*
-	 * It only makes sense to merge sync queues.
-	 */
-	if (!bfq_bfqq_sync(bfqq))
-		return NULL;
-	if (BFQQ_SEEKY(bfqq))
-		return NULL;
-
-	/*
-	 * Do not merge queues of different priority classes.
-	 */
-	if (bfq_class_rt(bfqq) != bfq_class_rt(cur_bfqq))
-		return NULL;
-
-	return bfqq;
-}
-
 /*
  * If enough samples have been computed, return the current max budget
  * stored in bfqd, which is dynamically updated according to the
@@ -1488,61 +1802,6 @@ static struct request *bfq_check_fifo(struct bfq_queue *bfqq)
 	return rq;
 }
 
-/* Must be called with the queue_lock held. */
-static int bfqq_process_refs(struct bfq_queue *bfqq)
-{
-	int process_refs, io_refs;
-
-	io_refs = bfqq->allocated[READ] + bfqq->allocated[WRITE];
-	process_refs = atomic_read(&bfqq->ref) - io_refs - bfqq->entity.on_st;
-	BUG_ON(process_refs < 0);
-	return process_refs;
-}
-
-static void bfq_setup_merge(struct bfq_queue *bfqq, struct bfq_queue *new_bfqq)
-{
-	int process_refs, new_process_refs;
-	struct bfq_queue *__bfqq;
-
-	/*
-	 * If there are no process references on the new_bfqq, then it is
-	 * unsafe to follow the ->new_bfqq chain as other bfqq's in the chain
-	 * may have dropped their last reference (not just their last process
-	 * reference).
-	 */
-	if (!bfqq_process_refs(new_bfqq))
-		return;
-
-	/* Avoid a circular list and skip interim queue merges. */
-	while ((__bfqq = new_bfqq->new_bfqq)) {
-		if (__bfqq == bfqq)
-			return;
-		new_bfqq = __bfqq;
-	}
-
-	process_refs = bfqq_process_refs(bfqq);
-	new_process_refs = bfqq_process_refs(new_bfqq);
-	/*
-	 * If the process for the bfqq has gone away, there is no
-	 * sense in merging the queues.
-	 */
-	if (process_refs == 0 || new_process_refs == 0)
-		return;
-
-	/*
-	 * Merge in the direction of the lesser amount of work.
-	 */
-	if (new_process_refs >= process_refs) {
-		bfqq->new_bfqq = new_bfqq;
-		atomic_add(process_refs, &new_bfqq->ref);
-	} else {
-		new_bfqq->new_bfqq = bfqq;
-		atomic_add(new_process_refs, &bfqq->ref);
-	}
-	bfq_log_bfqq(bfqq->bfqd, bfqq, "scheduling merge with queue %d",
-		new_bfqq->pid);
-}
-
 static inline unsigned long bfq_bfqq_budget_left(struct bfq_queue *bfqq)
 {
 	struct bfq_entity *entity = &bfqq->entity;
@@ -2269,7 +2528,7 @@ static inline bool bfq_bfqq_must_idle(struct bfq_queue *bfqq)
  */
 static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
 {
-	struct bfq_queue *bfqq, *new_bfqq = NULL;
+	struct bfq_queue *bfqq;
 	struct request *next_rq;
 	enum bfqq_expiration reason = BFQ_BFQQ_BUDGET_TIMEOUT;
 
@@ -2279,17 +2538,6 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
 
 	bfq_log_bfqq(bfqd, bfqq, "select_queue: already in-service queue");
 
-	/*
-         * If another queue has a request waiting within our mean seek
-         * distance, let it run. The expire code will check for close
-         * cooperators and put the close queue at the front of the
-         * service tree. If possible, merge the expiring queue with the
-         * new bfqq.
-         */
-        new_bfqq = bfq_close_cooperator(bfqd, bfqq);
-        if (new_bfqq != NULL && bfqq->new_bfqq == NULL)
-                bfq_setup_merge(bfqq, new_bfqq);
-
 	if (bfq_may_expire_for_budg_timeout(bfqq) &&
 	    !timer_pending(&bfqd->idle_slice_timer) &&
 	    !bfq_bfqq_must_idle(bfqq))
@@ -2328,10 +2576,7 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
 				bfq_clear_bfqq_wait_request(bfqq);
 				del_timer(&bfqd->idle_slice_timer);
 			}
-			if (new_bfqq == NULL)
-				goto keep_queue;
-			else
-				goto expire;
+			goto keep_queue;
 		}
 	}
 
@@ -2340,40 +2585,30 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
 	 * for a new request, or has requests waiting for a completion and
 	 * may idle after their completion, then keep it anyway.
 	 */
-	if (new_bfqq == NULL && (timer_pending(&bfqd->idle_slice_timer) ||
-	    (bfqq->dispatched != 0 && bfq_bfqq_must_not_expire(bfqq)))) {
+	if (timer_pending(&bfqd->idle_slice_timer) ||
+	    (bfqq->dispatched != 0 && bfq_bfqq_must_not_expire(bfqq))) {
 		bfqq = NULL;
 		goto keep_queue;
-	} else if (new_bfqq != NULL && timer_pending(&bfqd->idle_slice_timer)) {
-		/*
-		 * Expiring the queue because there is a close cooperator,
-		 * cancel timer.
-		 */
-		bfq_clear_bfqq_wait_request(bfqq);
-		del_timer(&bfqd->idle_slice_timer);
 	}
 
 	reason = BFQ_BFQQ_NO_MORE_REQUESTS;
 expire:
 	bfq_bfqq_expire(bfqd, bfqq, 0, reason);
 new_queue:
-	bfqq = bfq_set_in_service_queue(bfqd, new_bfqq);
+	bfqq = bfq_set_in_service_queue(bfqd);
 	bfq_log(bfqd, "select_queue: new queue %d returned",
 		bfqq != NULL ? bfqq->pid : 0);
 keep_queue:
 	return bfqq;
 }
 
-static void bfq_update_wr_data(struct bfq_data *bfqd,
-			       struct bfq_queue *bfqq)
+static void bfq_update_wr_data(struct bfq_data *bfqd, struct bfq_queue *bfqq)
 {
-	if (bfqq->wr_coeff > 1) { /* queue is being boosted */
-		struct bfq_entity *entity = &bfqq->entity;
-
+	struct bfq_entity *entity = &bfqq->entity;
+	if (bfqq->wr_coeff > 1) { /* queue is being weight-raised */
 		bfq_log_bfqq(bfqd, bfqq,
 			"raising period dur %u/%u msec, old coeff %u, w %d(%d)",
-			jiffies_to_msecs(jiffies -
-				bfqq->last_wr_start_finish),
+			jiffies_to_msecs(jiffies - bfqq->last_wr_start_finish),
 			jiffies_to_msecs(bfqq->wr_cur_max_time),
 			bfqq->wr_coeff,
 			bfqq->entity.weight, bfqq->entity.orig_weight);
@@ -2382,12 +2617,16 @@ static void bfq_update_wr_data(struct bfq_data *bfqd,
 		       entity->orig_weight * bfqq->wr_coeff);
 		if (entity->ioprio_changed)
 			bfq_log_bfqq(bfqd, bfqq, "WARN: pending prio change");
+
 		/*
 		 * If the queue was activated in a burst, or
 		 * too much time has elapsed from the beginning
-		 * of this weight-raising, then end weight raising.
+		 * of this weight-raising period, or the queue has
+		 * exceeded the acceptable number of cooperations,
+		 * then end weight raising.
 		 */
 		if (bfq_bfqq_in_large_burst(bfqq) ||
+		    bfq_bfqq_cooperations(bfqq) >= bfqd->bfq_coop_thresh ||
 		    time_is_before_jiffies(bfqq->last_wr_start_finish +
 					   bfqq->wr_cur_max_time)) {
 			bfqq->last_wr_start_finish = jiffies;
@@ -2396,11 +2635,13 @@ static void bfq_update_wr_data(struct bfq_data *bfqd,
 				     bfqq->last_wr_start_finish,
 				     jiffies_to_msecs(bfqq->wr_cur_max_time));
 			bfq_bfqq_end_wr(bfqq);
-			__bfq_entity_update_weight_prio(
-				bfq_entity_service_tree(entity),
-				entity);
 		}
 	}
+	/* Update weight both if it must be raised and if it must be lowered */
+	if ((entity->weight > entity->orig_weight) != (bfqq->wr_coeff > 1))
+		__bfq_entity_update_weight_prio(
+			bfq_entity_service_tree(entity),
+			entity);
 }
 
 /*
@@ -2647,6 +2888,25 @@ static inline void bfq_init_icq(struct io_cq *icq)
 	struct bfq_io_cq *bic = icq_to_bic(icq);
 
 	bic->ttime.last_end_request = jiffies;
+	/*
+	 * A newly created bic indicates that the process has just
+	 * started doing I/O, and is probably mapping into memory its
+	 * executable and libraries: it definitely needs weight raising.
+	 * There is however the possibility that the process performs,
+	 * for a while, I/O close to some other process. EQM intercepts
+	 * this behavior and may merge the queue corresponding to the
+	 * process  with some other queue, BEFORE the weight of the queue
+	 * is raised. Merged queues are not weight-raised (they are assumed
+	 * to belong to processes that benefit only from high throughput).
+	 * If the merge is basically the consequence of an accident, then
+	 * the queue will be split soon and will get back its old weight.
+	 * It is then important to write down somewhere that this queue
+	 * does need weight raising, even if it did not make it to get its
+	 * weight raised before being merged. To this purpose, we overload
+	 * the field raising_time_left and assign 1 to it, to mark the queue
+	 * as needing weight raising.
+	 */
+	bic->wr_time_left = 1;
 }
 
 static void bfq_exit_icq(struct io_cq *icq)
@@ -2660,6 +2920,13 @@ static void bfq_exit_icq(struct io_cq *icq)
 	}
 
 	if (bic->bfqq[BLK_RW_SYNC]) {
+		/*
+		 * If the bic is using a shared queue, put the reference
+		 * taken on the io_context when the bic started using a
+		 * shared bfq_queue.
+		 */
+		if (bfq_bfqq_coop(bic->bfqq[BLK_RW_SYNC]))
+			put_io_context(icq->ioc);
 		bfq_exit_bfqq(bfqd, bic->bfqq[BLK_RW_SYNC]);
 		bic->bfqq[BLK_RW_SYNC] = NULL;
 	}
@@ -2952,6 +3219,10 @@ static void bfq_update_idle_window(struct bfq_data *bfqd,
 	if (!bfq_bfqq_sync(bfqq) || bfq_class_idle(bfqq))
 		return;
 
+	/* Idle window just restored, statistics are meaningless. */
+	if (bfq_bfqq_just_split(bfqq))
+		return;
+
 	enable_idle = bfq_bfqq_idle_window(bfqq);
 
 	if (atomic_read(&bic->icq.ioc->active_ref) == 0 ||
@@ -2999,6 +3270,7 @@ static void bfq_rq_enqueued(struct bfq_data *bfqd, struct bfq_queue *bfqq,
 	if (bfqq->entity.service > bfq_max_budget(bfqd) / 8 ||
 	    !BFQQ_SEEKY(bfqq))
 		bfq_update_idle_window(bfqd, bfqq, bic);
+	bfq_clear_bfqq_just_split(bfqq);
 
 	bfq_log_bfqq(bfqd, bfqq,
 		     "rq_enqueued: idle_window=%d (seeky %d, mean %llu)",
@@ -3059,12 +3331,47 @@ static void bfq_rq_enqueued(struct bfq_data *bfqd, struct bfq_queue *bfqq,
 static void bfq_insert_request(struct request_queue *q, struct request *rq)
 {
 	struct bfq_data *bfqd = q->elevator->elevator_data;
-	struct bfq_queue *bfqq = RQ_BFQQ(rq);
+	struct bfq_queue *bfqq = RQ_BFQQ(rq), *new_bfqq;
 
 	assert_spin_locked(bfqd->queue->queue_lock);
 
+	/*
+	 * An unplug may trigger a requeue of a request from the device
+	 * driver: make sure we are in process context while trying to
+	 * merge two bfq_queues.
+	 */
+	if (!in_interrupt()) {
+		new_bfqq = bfq_setup_cooperator(bfqd, bfqq, rq, true);
+		if (new_bfqq != NULL) {
+			if (bic_to_bfqq(RQ_BIC(rq), 1) != bfqq)
+				new_bfqq = bic_to_bfqq(RQ_BIC(rq), 1);
+			/*
+			 * Release the request's reference to the old bfqq
+			 * and make sure one is taken to the shared queue.
+			 */
+			new_bfqq->allocated[rq_data_dir(rq)]++;
+			bfqq->allocated[rq_data_dir(rq)]--;
+			atomic_inc(&new_bfqq->ref);
+			bfq_put_queue(bfqq);
+			if (bic_to_bfqq(RQ_BIC(rq), 1) == bfqq)
+				bfq_merge_bfqqs(bfqd, RQ_BIC(rq),
+						bfqq, new_bfqq);
+			rq->elv.priv[1] = new_bfqq;
+			bfqq = new_bfqq;
+		} else
+			bfq_bfqq_increase_failed_cooperations(bfqq);
+	}
+
 	bfq_add_request(rq);
 
+	/*
+	 * Here a newly-created bfq_queue has already started a weight-raising
+	 * period: clear raising_time_left to prevent bfq_bfqq_save_state()
+	 * from assigning it a full weight-raising period. See the detailed
+	 * comments about this field in bfq_init_icq().
+	 */
+	if (bfqq->bic != NULL)
+		bfqq->bic->wr_time_left = 0;
 	rq_set_fifo_time(rq, jiffies + bfqd->bfq_fifo_expire[rq_is_sync(rq)]);
 	list_add_tail(&rq->queuelist, &bfqq->fifo);
 
@@ -3226,18 +3533,6 @@ static void bfq_put_request(struct request *rq)
 	}
 }
 
-static struct bfq_queue *
-bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic,
-		struct bfq_queue *bfqq)
-{
-	bfq_log_bfqq(bfqd, bfqq, "merging with queue %lu",
-		(long unsigned)bfqq->new_bfqq->pid);
-	bic_set_bfqq(bic, bfqq->new_bfqq, 1);
-	bfq_mark_bfqq_coop(bfqq->new_bfqq);
-	bfq_put_queue(bfqq);
-	return bic_to_bfqq(bic, 1);
-}
-
 /*
  * Returns NULL if a new bfqq should be allocated, or the old bfqq if this
  * was the last process referring to said bfqq.
@@ -3246,6 +3541,9 @@ static struct bfq_queue *
 bfq_split_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq)
 {
 	bfq_log_bfqq(bfqq->bfqd, bfqq, "splitting queue");
+
+	put_io_context(bic->icq.ioc);
+
 	if (bfqq_process_refs(bfqq) == 1) {
 		bfqq->pid = current->pid;
 		bfq_clear_bfqq_coop(bfqq);
@@ -3274,6 +3572,7 @@ static int bfq_set_request(struct request_queue *q, struct request *rq,
 	struct bfq_queue *bfqq;
 	struct bfq_group *bfqg;
 	unsigned long flags;
+	bool split = false;
 
 	might_sleep_if(gfp_mask & __GFP_WAIT);
 
@@ -3291,25 +3590,26 @@ new_queue:
 	if (bfqq == NULL || bfqq == &bfqd->oom_bfqq) {
 		bfqq = bfq_get_queue(bfqd, bfqg, is_sync, bic, gfp_mask);
 		bic_set_bfqq(bic, bfqq, is_sync);
+		if (split && is_sync) {
+			if ((bic->was_in_burst_list && bfqd->large_burst) ||
+			    bic->saved_in_large_burst)
+				bfq_mark_bfqq_in_large_burst(bfqq);
+			else {
+			    bfq_clear_bfqq_in_large_burst(bfqq);
+			    if (bic->was_in_burst_list)
+			       hlist_add_head(&bfqq->burst_list_node,
+				              &bfqd->burst_list);
+			}
+		}
 	} else {
-		/*
-		 * If the queue was seeky for too long, break it apart.
-		 */
+		/* If the queue was seeky for too long, break it apart. */
 		if (bfq_bfqq_coop(bfqq) && bfq_bfqq_split_coop(bfqq)) {
 			bfq_log_bfqq(bfqd, bfqq, "breaking apart bfqq");
 			bfqq = bfq_split_bfqq(bic, bfqq);
+			split = true;
 			if (!bfqq)
 				goto new_queue;
 		}
-
-		/*
-		 * Check to see if this queue is scheduled to merge with
-		 * another closely cooperating queue. The merging of queues
-		 * happens here as it must be done in process context.
-		 * The reference on new_bfqq was taken in merge_bfqqs.
-		 */
-		if (bfqq->new_bfqq != NULL)
-			bfqq = bfq_merge_bfqqs(bfqd, bic, bfqq);
 	}
 
 	bfqq->allocated[rw]++;
@@ -3320,6 +3620,26 @@ new_queue:
 	rq->elv.priv[0] = bic;
 	rq->elv.priv[1] = bfqq;
 
+	/*
+	 * If a bfq_queue has only one process reference, it is owned
+	 * by only one bfq_io_cq: we can set the bic field of the
+	 * bfq_queue to the address of that structure. Also, if the
+	 * queue has just been split, mark a flag so that the
+	 * information is available to the other scheduler hooks.
+	 */
+	if (likely(bfqq != &bfqd->oom_bfqq) && bfqq_process_refs(bfqq) == 1) {
+		bfqq->bic = bic;
+		if (split) {
+			bfq_mark_bfqq_just_split(bfqq);
+			/*
+			 * If the queue has just been split from a shared
+			 * queue, restore the idle window and the possible
+			 * weight raising period.
+			 */
+			bfq_bfqq_resume_state(bfqq, bic);
+		}
+	}
+
 	spin_unlock_irqrestore(q->queue_lock, flags);
 
 	return 0;
diff --git a/block/bfq-sched.c b/block/bfq-sched.c
index c3430993ec94..d0890c6d4c11 100644
--- a/block/bfq-sched.c
+++ b/block/bfq-sched.c
@@ -1085,34 +1085,6 @@ static struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd)
 	return bfqq;
 }
 
-/*
- * Forced extraction of the given queue.
- */
-static void bfq_get_next_queue_forced(struct bfq_data *bfqd,
-				      struct bfq_queue *bfqq)
-{
-	struct bfq_entity *entity;
-	struct bfq_sched_data *sd;
-
-	BUG_ON(bfqd->in_service_queue != NULL);
-
-	entity = &bfqq->entity;
-	/*
-	 * Bubble up extraction/update from the leaf to the root.
-	*/
-	for_each_entity(entity) {
-		sd = entity->sched_data;
-		bfq_update_budget(entity);
-		bfq_update_vtime(bfq_entity_service_tree(entity));
-		bfq_active_extract(bfq_entity_service_tree(entity), entity);
-		sd->in_service_entity = entity;
-		sd->next_in_service = NULL;
-		entity->service = 0;
-	}
-
-	return;
-}
-
 static void __bfq_bfqd_reset_in_service(struct bfq_data *bfqd)
 {
 	if (bfqd->in_service_bic != NULL) {
diff --git a/block/bfq.h b/block/bfq.h
index 619bcdd1ec15..aeb9bb4bbce7 100644
--- a/block/bfq.h
+++ b/block/bfq.h
@@ -218,18 +218,21 @@ struct bfq_group;
  *                      idle @bfq_queue with no outstanding requests, then
  *                      the task associated with the queue it is deemed as
  *                      soft real-time (see the comments to the function
- *                      bfq_bfqq_softrt_next_start()).
+ *                      bfq_bfqq_softrt_next_start())
  * @last_idle_bklogged: time of the last transition of the @bfq_queue from
  *                      idle to backlogged
  * @service_from_backlogged: cumulative service received from the @bfq_queue
  *                           since the last transition from idle to
  *                           backlogged
+ * @bic: pointer to the bfq_io_cq owning the bfq_queue, set to %NULL if the
+ *	 queue is shared
  *
- * A bfq_queue is a leaf request queue; it can be associated with an io_context
- * or more, if it is async or shared between cooperating processes. @cgroup
- * holds a reference to the cgroup, to be sure that it does not disappear while
- * a bfqq still references it (mostly to avoid races between request issuing and
- * task migration followed by cgroup destruction).
+ * A bfq_queue is a leaf request queue; it can be associated with an
+ * io_context or more, if it  is  async or shared  between  cooperating
+ * processes. @cgroup holds a reference to the cgroup, to be sure that it
+ * does not disappear while a bfqq still references it (mostly to avoid
+ * races between request issuing and task migration followed by cgroup
+ * destruction).
  * All the fields are protected by the queue lock of the containing bfqd.
  */
 struct bfq_queue {
@@ -269,6 +272,7 @@ struct bfq_queue {
 	unsigned int requests_within_timer;
 
 	pid_t pid;
+	struct bfq_io_cq *bic;
 
 	/* weight-raising fields */
 	unsigned long wr_cur_max_time;
@@ -298,12 +302,42 @@ struct bfq_ttime {
  * @icq: associated io_cq structure
  * @bfqq: array of two process queues, the sync and the async
  * @ttime: associated @bfq_ttime struct
+ * @wr_time_left: snapshot of the time left before weight raising ends
+ *                for the sync queue associated to this process; this
+ *		  snapshot is taken to remember this value while the weight
+ *		  raising is suspended because the queue is merged with a
+ *		  shared queue, and is used to set @raising_cur_max_time
+ *		  when the queue is split from the shared queue and its
+ *		  weight is raised again
+ * @saved_idle_window: same purpose as the previous field for the idle
+ *                     window
+ * @saved_IO_bound: same purpose as the previous two fields for the I/O
+ *                  bound classification of a queue
+ * @saved_in_large_burst: same purpose as the previous fields for the
+ *                        value of the field keeping the queue's belonging
+ *                        to a large burst
+ * @was_in_burst_list: true if the queue belonged to a burst list
+ *                     before its merge with another cooperating queue
+ * @cooperations: counter of consecutive successful queue merges underwent
+ *                by any of the process' @bfq_queues
+ * @failed_cooperations: counter of consecutive failed queue merges of any
+ *                       of the process' @bfq_queues
  */
 struct bfq_io_cq {
 	struct io_cq icq; /* must be the first member */
 	struct bfq_queue *bfqq[2];
 	struct bfq_ttime ttime;
 	int ioprio;
+
+	unsigned int wr_time_left;
+	bool saved_idle_window;
+	bool saved_IO_bound;
+
+	bool saved_in_large_burst;
+	bool was_in_burst_list;
+
+	unsigned int cooperations;
+	unsigned int failed_cooperations;
 };
 
 enum bfq_device_speed {
@@ -536,7 +570,7 @@ enum bfqq_state_flags {
 	BFQ_BFQQ_FLAG_idle_window,	/* slice idling enabled */
 	BFQ_BFQQ_FLAG_sync,		/* synchronous queue */
 	BFQ_BFQQ_FLAG_budget_new,	/* no completion with this budget */
-	BFQ_BFQQ_FLAG_IO_bound,         /*
+	BFQ_BFQQ_FLAG_IO_bound,		/*
 					 * bfqq has timed-out at least once
 					 * having consumed at most 2/10 of
 					 * its budget
@@ -549,12 +583,13 @@ enum bfqq_state_flags {
 					 * bfqq has proved to be slow and
 					 * seeky until budget timeout
 					 */
-	BFQ_BFQQ_FLAG_softrt_update,    /*
+	BFQ_BFQQ_FLAG_softrt_update,	/*
 					 * may need softrt-next-start
 					 * update
 					 */
 	BFQ_BFQQ_FLAG_coop,		/* bfqq is shared */
-	BFQ_BFQQ_FLAG_split_coop,	/* shared bfqq will be splitted */
+	BFQ_BFQQ_FLAG_split_coop,	/* shared bfqq will be split */
+	BFQ_BFQQ_FLAG_just_split,	/* queue has just been split */
 };
 
 #define BFQ_BFQQ_FNS(name)						\
@@ -583,6 +618,7 @@ BFQ_BFQQ_FNS(in_large_burst);
 BFQ_BFQQ_FNS(constantly_seeky);
 BFQ_BFQQ_FNS(coop);
 BFQ_BFQQ_FNS(split_coop);
+BFQ_BFQQ_FNS(just_split);
 BFQ_BFQQ_FNS(softrt_update);
 #undef BFQ_BFQQ_FNS