1 files changed, 146 insertions, 145 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 2540dfaa3e38..102ebc2c5c34 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -6,7 +6,6 @@
  *
  *  Copyright (C) 2003 Jens Axboe <axboe@suse.de>
  */
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/blkdev.h>
 #include <linux/elevator.h>
@@ -26,14 +25,14 @@ static const int cfq_back_penalty = 2;		/* penalty of a backwards seek */
 static const int cfq_slice_sync = HZ / 10;
 static int cfq_slice_async = HZ / 25;
 static const int cfq_slice_async_rq = 2;
-static int cfq_slice_idle = HZ / 70;
+static int cfq_slice_idle = HZ / 125;
 
 #define CFQ_IDLE_GRACE		(HZ / 10)
 #define CFQ_SLICE_SCALE		(5)
 
 #define CFQ_KEY_ASYNC		(0)
 
-static DEFINE_RWLOCK(cfq_exit_lock);
+static DEFINE_SPINLOCK(cfq_exit_lock);
 
 /*
  * for the hash of cfqq inside the cfqd
@@ -60,16 +59,6 @@ static DEFINE_RWLOCK(cfq_exit_lock);
 /*
  * rb-tree defines
  */
-#define RB_NONE			(2)
-#define RB_EMPTY(node)		((node)->rb_node == NULL)
-#define RB_CLEAR_COLOR(node)	(node)->rb_color = RB_NONE
-#define RB_CLEAR(node)		do {	\
-	(node)->rb_parent = NULL;	\
-	RB_CLEAR_COLOR((node));		\
-	(node)->rb_right = NULL;	\
-	(node)->rb_left = NULL;		\
-} while (0)
-#define RB_CLEAR_ROOT(root)	((root)->rb_node = NULL)
 #define rb_entry_crq(node)	rb_entry((node), struct cfq_rq, rb_node)
 #define rq_rb_key(rq)		(rq)->sector
 
@@ -128,11 +117,10 @@ struct cfq_data {
 	 */
 	struct hlist_head *crq_hash;
 
-	unsigned int max_queued;
-
 	mempool_t *crq_pool;
 
 	int rq_in_driver;
+	int hw_tag;
 
 	/*
 	 * schedule slice state info
@@ -283,8 +271,6 @@ static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int, unsi
 static void cfq_dispatch_insert(request_queue_t *, struct cfq_rq *);
 static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk, gfp_t gfp_mask);
 
-#define process_sync(tsk)	((tsk)->flags & PF_SYNCWRITE)
-
 /*
  * lots of deadline iosched dupes, can be abstracted later...
  */
@@ -340,7 +326,7 @@ static int cfq_queue_empty(request_queue_t *q)
 
 static inline pid_t cfq_queue_pid(struct task_struct *task, int rw)
 {
-	if (rw == READ || process_sync(task))
+	if (rw == READ || rw == WRITE_SYNC)
 		return task->pid;
 
 	return CFQ_KEY_ASYNC;
@@ -500,10 +486,13 @@ static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted)
 
 	/*
 	 * if queue was preempted, just add to front to be fair. busy_rr
-	 * isn't sorted.
+	 * isn't sorted, but insert at the back for fairness.
 	 */
 	if (preempted || list == &cfqd->busy_rr) {
-		list_add(&cfqq->cfq_list, list);
+		if (preempted)
+			list = list->prev;
+
+		list_add_tail(&cfqq->cfq_list, list);
 		return;
 	}
 
@@ -563,9 +552,8 @@ static inline void cfq_del_crq_rb(struct cfq_rq *crq)
 	cfq_update_next_crq(crq);
 
 	rb_erase(&crq->rb_node, &cfqq->sort_list);
-	RB_CLEAR_COLOR(&crq->rb_node);
 
-	if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY(&cfqq->sort_list))
+	if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
 		cfq_del_cfqq_rr(cfqd, cfqq);
 }
 
@@ -664,6 +652,15 @@ static void cfq_activate_request(request_queue_t *q, struct request *rq)
 	struct cfq_data *cfqd = q->elevator->elevator_data;
 
 	cfqd->rq_in_driver++;
+
+	/*
+	 * If the depth is larger 1, it really could be queueing. But lets
+	 * make the mark a little higher - idling could still be good for
+	 * low queueing, and a low queueing number could also just indicate
+	 * a SCSI mid layer like behaviour where limit+1 is often seen.
+	 */
+	if (!cfqd->hw_tag && cfqd->rq_in_driver > 4)
+		cfqd->hw_tag = 1;
 }
 
 static void cfq_deactivate_request(request_queue_t *q, struct request *rq)
@@ -879,6 +876,13 @@ static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd)
 		cfqq = list_entry_cfqq(cfqd->cur_rr.next);
 
 	/*
+	 * If no new queues are available, check if the busy list has some
+	 * before falling back to idle io.
+	 */
+	if (!cfqq && !list_empty(&cfqd->busy_rr))
+		cfqq = list_entry_cfqq(cfqd->busy_rr.next);
+
+	/*
 	 * if we have idle queues and no rt or be queues had pending
 	 * requests, either allow immediate service if the grace period
 	 * has passed or arm the idle grace timer
@@ -896,13 +900,15 @@ static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd)
 	return cfqq;
 }
 
+#define CIC_SEEKY(cic) ((cic)->seek_mean > (128 * 1024))
+
 static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 
 {
 	struct cfq_io_context *cic;
 	unsigned long sl;
 
-	WARN_ON(!RB_EMPTY(&cfqq->sort_list));
+	WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list));
 	WARN_ON(cfqq != cfqd->active_queue);
 
 	/*
@@ -929,7 +935,7 @@ static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 	 * fair distribution of slice time for a process doing back-to-back
 	 * seeks. so allow a little bit of time for him to submit a new rq
 	 */
-	if (sample_valid(cic->seek_samples) && cic->seek_mean > 131072)
+	if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic))
 		sl = 2;
 
 	mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
@@ -940,11 +946,15 @@ static void cfq_dispatch_insert(request_queue_t *q, struct cfq_rq *crq)
 {
 	struct cfq_data *cfqd = q->elevator->elevator_data;
 	struct cfq_queue *cfqq = crq->cfq_queue;
+	struct request *rq;
 
 	cfqq->next_crq = cfq_find_next_crq(cfqd, cfqq, crq);
 	cfq_remove_request(crq->request);
 	cfqq->on_dispatch[cfq_crq_is_sync(crq)]++;
 	elv_dispatch_sort(q, crq->request);
+
+	rq = list_entry(q->queue_head.prev, struct request, queuelist);
+	cfqd->last_sector = rq->sector + rq->nr_sectors;
 }
 
 /*
@@ -1026,10 +1036,12 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
 	 * if queue has requests, dispatch one. if not, check if
 	 * enough slice is left to wait for one
 	 */
-	if (!RB_EMPTY(&cfqq->sort_list))
+	if (!RB_EMPTY_ROOT(&cfqq->sort_list))
 		goto keep_queue;
-	else if (cfq_cfqq_class_sync(cfqq) &&
-		 time_before(now, cfqq->slice_end)) {
+	else if (cfq_cfqq_dispatched(cfqq)) {
+		cfqq = NULL;
+		goto keep_queue;
+	} else if (cfq_cfqq_class_sync(cfqq)) {
 		if (cfq_arm_slice_timer(cfqd, cfqq))
 			return NULL;
 	}
@@ -1048,7 +1060,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 {
 	int dispatched = 0;
 
-	BUG_ON(RB_EMPTY(&cfqq->sort_list));
+	BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list));
 
 	do {
 		struct cfq_rq *crq;
@@ -1072,14 +1084,13 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 			cfqd->active_cic = crq->io_context;
 		}
 
-		if (RB_EMPTY(&cfqq->sort_list))
+		if (RB_EMPTY_ROOT(&cfqq->sort_list))
 			break;
 
 	} while (dispatched < max_dispatch);
 
 	/*
-	 * if slice end isn't set yet, set it. if at least one request was
-	 * sync, use the sync time slice value
+	 * if slice end isn't set yet, set it.
 	 */
 	if (!cfqq->slice_end)
 		cfq_set_prio_slice(cfqd, cfqq);
@@ -1090,7 +1101,8 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 	 */
 	if ((!cfq_cfqq_sync(cfqq) &&
 	    cfqd->dispatch_slice >= cfq_prio_to_maxrq(cfqd, cfqq)) ||
-	    cfq_class_idle(cfqq))
+	    cfq_class_idle(cfqq) ||
+	    !cfq_cfqq_idle_window(cfqq))
 		cfq_slice_expired(cfqd, 0);
 
 	return dispatched;
@@ -1099,10 +1111,11 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 static int
 cfq_forced_dispatch_cfqqs(struct list_head *list)
 {
-	int dispatched = 0;
 	struct cfq_queue *cfqq, *next;
 	struct cfq_rq *crq;
+	int dispatched;
 
+	dispatched = 0;
 	list_for_each_entry_safe(cfqq, next, list, cfq_list) {
 		while ((crq = cfqq->next_crq)) {
 			cfq_dispatch_insert(cfqq->cfqd->queue, crq);
@@ -1110,6 +1123,7 @@ cfq_forced_dispatch_cfqqs(struct list_head *list)
 		}
 		BUG_ON(!list_empty(&cfqq->fifo));
 	}
+
 	return dispatched;
 }
 
@@ -1136,7 +1150,8 @@ static int
 cfq_dispatch_requests(request_queue_t *q, int force)
 {
 	struct cfq_data *cfqd = q->elevator->elevator_data;
-	struct cfq_queue *cfqq;
+	struct cfq_queue *cfqq, *prev_cfqq;
+	int dispatched;
 
 	if (!cfqd->busy_queues)
 		return 0;
@@ -1144,10 +1159,17 @@ cfq_dispatch_requests(request_queue_t *q, int force)
 	if (unlikely(force))
 		return cfq_forced_dispatch(cfqd);
 
-	cfqq = cfq_select_queue(cfqd);
-	if (cfqq) {
+	dispatched = 0;
+	prev_cfqq = NULL;
+	while ((cfqq = cfq_select_queue(cfqd)) != NULL) {
 		int max_dispatch;
 
+		/*
+		 * Don't repeat dispatch from the previous queue.
+		 */
+		if (prev_cfqq == cfqq)
+			break;
+
 		cfq_clear_cfqq_must_dispatch(cfqq);
 		cfq_clear_cfqq_wait_request(cfqq);
 		del_timer(&cfqd->idle_slice_timer);
@@ -1156,10 +1178,19 @@ cfq_dispatch_requests(request_queue_t *q, int force)
 		if (cfq_class_idle(cfqq))
 			max_dispatch = 1;
 
-		return __cfq_dispatch_requests(cfqd, cfqq, max_dispatch);
+		dispatched += __cfq_dispatch_requests(cfqd, cfqq, max_dispatch);
+
+		/*
+		 * If the dispatch cfqq has idling enabled and is still
+		 * the active queue, break out.
+		 */
+		if (cfq_cfqq_idle_window(cfqq) && cfqd->active_queue)
+			break;
+
+		prev_cfqq = cfqq;
 	}
 
-	return 0;
+	return dispatched;
 }
 
 /*
@@ -1284,7 +1315,7 @@ static void cfq_exit_io_context(struct io_context *ioc)
 	/*
 	 * put the reference this task is holding to the various queues
 	 */
-	read_lock_irqsave(&cfq_exit_lock, flags);
+	spin_lock_irqsave(&cfq_exit_lock, flags);
 
 	n = rb_first(&ioc->cic_root);
 	while (n != NULL) {
@@ -1294,7 +1325,7 @@ static void cfq_exit_io_context(struct io_context *ioc)
 		n = rb_next(n);
 	}
 
-	read_unlock_irqrestore(&cfq_exit_lock, flags);
+	spin_unlock_irqrestore(&cfq_exit_lock, flags);
 }
 
 static struct cfq_io_context *
@@ -1303,17 +1334,11 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
 	struct cfq_io_context *cic = kmem_cache_alloc(cfq_ioc_pool, gfp_mask);
 
 	if (cic) {
-		RB_CLEAR(&cic->rb_node);
-		cic->key = NULL;
-		cic->cfqq[ASYNC] = NULL;
-		cic->cfqq[SYNC] = NULL;
+		memset(cic, 0, sizeof(*cic));
 		cic->last_end_request = jiffies;
-		cic->ttime_total = 0;
-		cic->ttime_samples = 0;
-		cic->ttime_mean = 0;
+		INIT_LIST_HEAD(&cic->queue_list);
 		cic->dtor = cfq_free_io_context;
 		cic->exit = cfq_exit_io_context;
-		INIT_LIST_HEAD(&cic->queue_list);
 		atomic_inc(&ioc_count);
 	}
 
@@ -1371,25 +1396,28 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
 {
 	struct cfq_data *cfqd = cic->key;
 	struct cfq_queue *cfqq;
-	if (cfqd) {
-		spin_lock(cfqd->queue->queue_lock);
-		cfqq = cic->cfqq[ASYNC];
-		if (cfqq) {
-			struct cfq_queue *new_cfqq;
-			new_cfqq = cfq_get_queue(cfqd, CFQ_KEY_ASYNC,
-						cic->ioc->task, GFP_ATOMIC);
-			if (new_cfqq) {
-				cic->cfqq[ASYNC] = new_cfqq;
-				cfq_put_queue(cfqq);
-			}
-		}
-		cfqq = cic->cfqq[SYNC];
-		if (cfqq) {
-			cfq_mark_cfqq_prio_changed(cfqq);
-			cfq_init_prio_data(cfqq);
+
+	if (unlikely(!cfqd))
+		return;
+
+	spin_lock(cfqd->queue->queue_lock);
+
+	cfqq = cic->cfqq[ASYNC];
+	if (cfqq) {
+		struct cfq_queue *new_cfqq;
+		new_cfqq = cfq_get_queue(cfqd, CFQ_KEY_ASYNC, cic->ioc->task,
+					 GFP_ATOMIC);
+		if (new_cfqq) {
+			cic->cfqq[ASYNC] = new_cfqq;
+			cfq_put_queue(cfqq);
 		}
-		spin_unlock(cfqd->queue->queue_lock);
 	}
+
+	cfqq = cic->cfqq[SYNC];
+	if (cfqq)
+		cfq_mark_cfqq_prio_changed(cfqq);
+
+	spin_unlock(cfqd->queue->queue_lock);
 }
 
 /*
@@ -1400,17 +1428,17 @@ static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio)
 	struct cfq_io_context *cic;
 	struct rb_node *n;
 
-	write_lock(&cfq_exit_lock);
+	spin_lock(&cfq_exit_lock);
 
 	n = rb_first(&ioc->cic_root);
 	while (n != NULL) {
 		cic = rb_entry(n, struct cfq_io_context, rb_node);
- 
+
 		changed_ioprio(cic);
 		n = rb_next(n);
 	}
 
-	write_unlock(&cfq_exit_lock);
+	spin_unlock(&cfq_exit_lock);
 
 	return 0;
 }
@@ -1446,7 +1474,6 @@ retry:
 
 		INIT_HLIST_NODE(&cfqq->cfq_hash);
 		INIT_LIST_HEAD(&cfqq->cfq_list);
-		RB_CLEAR_ROOT(&cfqq->sort_list);
 		INIT_LIST_HEAD(&cfqq->fifo);
 
 		cfqq->key = key;
@@ -1475,9 +1502,10 @@ out:
 static void
 cfq_drop_dead_cic(struct io_context *ioc, struct cfq_io_context *cic)
 {
-	read_lock(&cfq_exit_lock);
+	spin_lock(&cfq_exit_lock);
 	rb_erase(&cic->rb_node, &ioc->cic_root);
-	read_unlock(&cfq_exit_lock);
+	list_del_init(&cic->queue_list);
+	spin_unlock(&cfq_exit_lock);
 	kmem_cache_free(cfq_ioc_pool, cic);
 	atomic_dec(&ioc_count);
 }
@@ -1545,11 +1573,11 @@ restart:
 			BUG();
 	}
 
-	read_lock(&cfq_exit_lock);
+	spin_lock(&cfq_exit_lock);
 	rb_link_node(&cic->rb_node, parent, p);
 	rb_insert_color(&cic->rb_node, &ioc->cic_root);
 	list_add(&cic->queue_list, &cfqd->cic_list);
-	read_unlock(&cfq_exit_lock);
+	spin_unlock(&cfq_exit_lock);
 }
 
 /*
@@ -1648,7 +1676,8 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 {
 	int enable_idle = cfq_cfqq_idle_window(cfqq);
 
-	if (!cic->ioc->task || !cfqd->cfq_slice_idle)
+	if (!cic->ioc->task || !cfqd->cfq_slice_idle ||
+	    (cfqd->hw_tag && CIC_SEEKY(cic)))
 		enable_idle = 0;
 	else if (sample_valid(cic->ttime_samples)) {
 		if (cic->ttime_mean > cfqd->cfq_slice_idle)
@@ -1678,7 +1707,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
 		return 0;
 
 	if (!cfqq)
-		return 1;
+		return 0;
 
 	if (cfq_class_idle(cfqq))
 		return 1;
@@ -1710,7 +1739,7 @@ static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 		cfqq->slice_left = cfq_prio_to_slice(cfqd, cfqq) / 2;
 
 	cfqq->slice_end = cfqq->slice_left + jiffies;
-	__cfq_slice_expired(cfqd, cfqq, 1);
+	cfq_slice_expired(cfqd, 1);
 	__cfq_set_active_queue(cfqd, cfqq);
 }
 
@@ -1735,18 +1764,24 @@ static void
 cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 		 struct cfq_rq *crq)
 {
-	struct cfq_io_context *cic;
-
-	cfqq->next_crq = cfq_choose_req(cfqd, cfqq->next_crq, crq);
+	struct cfq_io_context *cic = crq->io_context;
 
 	/*
 	 * we never wait for an async request and we don't allow preemption
 	 * of an async request. so just return early
 	 */
-	if (!cfq_crq_is_sync(crq))
+	if (!cfq_crq_is_sync(crq)) {
+		/*
+		 * sync process issued an async request, if it's waiting
+		 * then expire it and kick rq handling.
+		 */
+		if (cic == cfqd->active_cic &&
+		    del_timer(&cfqd->idle_slice_timer)) {
+			cfq_slice_expired(cfqd, 0);
+			cfq_start_queueing(cfqd, cfqq);
+		}
 		return;
-
-	cic = crq->io_context;
+	}
 
 	cfq_update_io_thinktime(cfqd, cic);
 	cfq_update_io_seektime(cfqd, cic, crq);
@@ -1819,11 +1854,23 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq)
 			cfqq->service_last = now;
 			cfq_resort_rr_list(cfqq, 0);
 		}
-		cfq_schedule_dispatch(cfqd);
 	}
 
-	if (cfq_crq_is_sync(crq))
+	if (sync)
 		crq->io_context->last_end_request = now;
+
+	/*
+	 * If this is the active queue, check if it needs to be expired,
+	 * or if we want to idle in case it has no pending requests.
+	 */
+	if (cfqd->active_queue == cfqq) {
+		if (time_after(now, cfqq->slice_end))
+			cfq_slice_expired(cfqd, 0);
+		else if (sync && RB_EMPTY_ROOT(&cfqq->sort_list)) {
+			if (!cfq_arm_slice_timer(cfqd, cfqq))
+				cfq_schedule_dispatch(cfqd);
+		}
+	}
 }
 
 static struct request *
@@ -1890,7 +1937,6 @@ static inline int
 __cfq_may_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 		struct task_struct *task, int rw)
 {
-#if 1
 	if ((cfq_cfqq_wait_request(cfqq) || cfq_cfqq_must_alloc(cfqq)) &&
 	    !cfq_cfqq_must_alloc_slice(cfqq)) {
 		cfq_mark_cfqq_must_alloc_slice(cfqq);
@@ -1898,39 +1944,6 @@ __cfq_may_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 	}
 
 	return ELV_MQUEUE_MAY;
-#else
-	if (!cfqq || task->flags & PF_MEMALLOC)
-		return ELV_MQUEUE_MAY;
-	if (!cfqq->allocated[rw] || cfq_cfqq_must_alloc(cfqq)) {
-		if (cfq_cfqq_wait_request(cfqq))
-			return ELV_MQUEUE_MUST;
-
-		/*
-		 * only allow 1 ELV_MQUEUE_MUST per slice, otherwise we
-		 * can quickly flood the queue with writes from a single task
-		 */
-		if (rw == READ || !cfq_cfqq_must_alloc_slice(cfqq)) {
-			cfq_mark_cfqq_must_alloc_slice(cfqq);
-			return ELV_MQUEUE_MUST;
-		}
-
-		return ELV_MQUEUE_MAY;
-	}
-	if (cfq_class_idle(cfqq))
-		return ELV_MQUEUE_NO;
-	if (cfqq->allocated[rw] >= cfqd->max_queued) {
-		struct io_context *ioc = get_io_context(GFP_ATOMIC);
-		int ret = ELV_MQUEUE_NO;
-
-		if (ioc && ioc->nr_batch_requests)
-			ret = ELV_MQUEUE_MAY;
-
-		put_io_context(ioc);
-		return ret;
-	}
-
-	return ELV_MQUEUE_MAY;
-#endif
 }
 
 static int cfq_may_queue(request_queue_t *q, int rw, struct bio *bio)
@@ -1959,16 +1972,13 @@ static int cfq_may_queue(request_queue_t *q, int rw, struct bio *bio)
 static void cfq_check_waiters(request_queue_t *q, struct cfq_queue *cfqq)
 {
 	struct cfq_data *cfqd = q->elevator->elevator_data;
-	struct request_list *rl = &q->rq;
 
-	if (cfqq->allocated[READ] <= cfqd->max_queued || cfqd->rq_starved) {
+	if (unlikely(cfqd->rq_starved)) {
+		struct request_list *rl = &q->rq;
+
 		smp_mb();
 		if (waitqueue_active(&rl->wait[READ]))
 			wake_up(&rl->wait[READ]);
-	}
-
-	if (cfqq->allocated[WRITE] <= cfqd->max_queued || cfqd->rq_starved) {
-		smp_mb();
 		if (waitqueue_active(&rl->wait[WRITE]))
 			wake_up(&rl->wait[WRITE]);
 	}
@@ -2042,7 +2052,7 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
 
 	crq = mempool_alloc(cfqd->crq_pool, gfp_mask);
 	if (crq) {
-		RB_CLEAR(&crq->rb_node);
+		RB_CLEAR_NODE(&crq->rb_node);
 		crq->rb_key = 0;
 		crq->request = rq;
 		INIT_HLIST_NODE(&crq->hash);
@@ -2128,16 +2138,13 @@ static void cfq_idle_slice_timer(unsigned long data)
 		 * only expire and reinvoke request handler, if there are
 		 * other queues with pending requests
 		 */
-		if (!cfqd->busy_queues) {
-			cfqd->idle_slice_timer.expires = min(now + cfqd->cfq_slice_idle, cfqq->slice_end);
-			add_timer(&cfqd->idle_slice_timer);
+		if (!cfqd->busy_queues)
 			goto out_cont;
-		}
 
 		/*
 		 * not expired and it has a request pending, let it dispatch
 		 */
-		if (!RB_EMPTY(&cfqq->sort_list)) {
+		if (!RB_EMPTY_ROOT(&cfqq->sort_list)) {
 			cfq_mark_cfqq_must_dispatch(cfqq);
 			goto out_kick;
 		}
@@ -2164,10 +2171,9 @@ static void cfq_idle_class_timer(unsigned long data)
 	 * race with a non-idle queue, reset timer
 	 */
 	end = cfqd->last_end_request + CFQ_IDLE_GRACE;
-	if (!time_after_eq(jiffies, end)) {
-		cfqd->idle_class_timer.expires = end;
-		add_timer(&cfqd->idle_class_timer);
-	} else
+	if (!time_after_eq(jiffies, end))
+		mod_timer(&cfqd->idle_class_timer, end);
+	else
 		cfq_schedule_dispatch(cfqd);
 
 	spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
@@ -2187,7 +2193,7 @@ static void cfq_exit_queue(elevator_t *e)
 
 	cfq_shutdown_timer_wq(cfqd);
 
-	write_lock(&cfq_exit_lock);
+	spin_lock(&cfq_exit_lock);
 	spin_lock_irq(q->queue_lock);
 
 	if (cfqd->active_queue)
@@ -2210,7 +2216,7 @@ static void cfq_exit_queue(elevator_t *e)
 	}
 
 	spin_unlock_irq(q->queue_lock);
-	write_unlock(&cfq_exit_lock);
+	spin_unlock(&cfq_exit_lock);
 
 	cfq_shutdown_timer_wq(cfqd);
 
@@ -2220,14 +2226,14 @@ static void cfq_exit_queue(elevator_t *e)
 	kfree(cfqd);
 }
 
-static int cfq_init_queue(request_queue_t *q, elevator_t *e)
+static void *cfq_init_queue(request_queue_t *q, elevator_t *e)
 {
 	struct cfq_data *cfqd;
 	int i;
 
 	cfqd = kmalloc(sizeof(*cfqd), GFP_KERNEL);
 	if (!cfqd)
-		return -ENOMEM;
+		return NULL;
 
 	memset(cfqd, 0, sizeof(*cfqd));
 
@@ -2257,13 +2263,8 @@ static int cfq_init_queue(request_queue_t *q, elevator_t *e)
 	for (i = 0; i < CFQ_QHASH_ENTRIES; i++)
 		INIT_HLIST_HEAD(&cfqd->cfq_hash[i]);
 
-	e->elevator_data = cfqd;
-
 	cfqd->queue = q;
 
-	cfqd->max_queued = q->nr_requests / 4;
-	q->nr_batching = cfq_queued;
-
 	init_timer(&cfqd->idle_slice_timer);
 	cfqd->idle_slice_timer.function = cfq_idle_slice_timer;
 	cfqd->idle_slice_timer.data = (unsigned long) cfqd;
@@ -2285,14 +2286,14 @@ static int cfq_init_queue(request_queue_t *q, elevator_t *e)
 	cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
 	cfqd->cfq_slice_idle = cfq_slice_idle;
 
-	return 0;
+	return cfqd;
 out_crqpool:
 	kfree(cfqd->cfq_hash);
 out_cfqhash:
 	kfree(cfqd->crq_hash);
 out_crqhash:
 	kfree(cfqd);
-	return -ENOMEM;
+	return NULL;
 }
 
 static void cfq_slab_kill(void)