diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index 421bef9..8bd1051 100644
--- a/block/Kconfig.iosched
+++ b/block/Kconfig.iosched
@@ -32,13 +32,6 @@ config IOSCHED_CFQ
 
 	  This is the default I/O scheduler.
 
-config CFQ_GROUP_IOSCHED
-	bool "CFQ Group Scheduling support"
-	depends on IOSCHED_CFQ && BLK_CGROUP
-	default n
-	---help---
-	  Enable group IO scheduling in CFQ.
-
 choice
 	prompt "Default I/O scheduler"
 	default DEFAULT_CFQ
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index fc53555..fab01e2 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -14,7 +14,6 @@
 #include <linux/rbtree.h>
 #include <linux/ioprio.h>
 #include <linux/blktrace_api.h>
-#include <linux/blk-cgroup.h>
 #include "blk.h"
 
 /*
@@ -31,7 +30,6 @@ 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 / 125;
-static int cfq_group_idle = HZ / 125;
 static const int cfq_target_latency = HZ * 3/10; /* 300 ms */
 static const int cfq_hist_divisor = 4;
 
@@ -55,7 +53,6 @@ static const int cfq_hist_divisor = 4;
 
 #define RQ_CIC(rq)		icq_to_cic((rq)->elv.icq)
 #define RQ_CFQQ(rq)		(struct cfq_queue *) ((rq)->elv.priv[0])
-#define RQ_CFQG(rq)		(struct cfq_group *) ((rq)->elv.priv[1])
 
 static struct kmem_cache *cfq_pool;
 
@@ -64,12 +61,6 @@ static struct kmem_cache *cfq_pool;
 #define cfq_class_rt(cfqq)	((cfqq)->ioprio_class == IOPRIO_CLASS_RT)
 
 #define sample_valid(samples)	((samples) > 80)
-#define rb_entry_cfqg(node)	rb_entry((node), struct cfq_group, rb_node)
-
-/* blkio-related constants */
-#define CFQ_WEIGHT_LEGACY_MIN	10
-#define CFQ_WEIGHT_LEGACY_DFL	500
-#define CFQ_WEIGHT_LEGACY_MAX	1000
 
 struct cfq_ttime {
 	unsigned long last_end_request;
@@ -149,7 +140,6 @@ struct cfq_queue {
 
 	struct cfq_rb_root *service_tree;
 	struct cfq_queue *new_cfqq;
-	struct cfq_group *cfqg;
 	/* Number of sectors dispatched from queue in single dispatch round */
 	unsigned long nr_sectors;
 };
@@ -174,111 +164,20 @@ enum wl_type_t {
 	SYNC_WORKLOAD = 2
 };
 
-struct cfqg_stats {
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-	/* number of ios merged */
-	struct blkg_rwstat		merged;
-	/* total time spent on device in ns, may not be accurate w/ queueing */
-	struct blkg_rwstat		service_time;
-	/* total time spent waiting in scheduler queue in ns */
-	struct blkg_rwstat		wait_time;
-	/* number of IOs queued up */
-	struct blkg_rwstat		queued;
-	/* total disk time and nr sectors dispatched by this group */
-	struct blkg_stat		time;
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-	/* time not charged to this cgroup */
-	struct blkg_stat		unaccounted_time;
-	/* sum of number of ios queued across all samples */
-	struct blkg_stat		avg_queue_size_sum;
-	/* count of samples taken for average */
-	struct blkg_stat		avg_queue_size_samples;
-	/* how many times this group has been removed from service tree */
-	struct blkg_stat		dequeue;
-	/* total time spent waiting for it to be assigned a timeslice. */
-	struct blkg_stat		group_wait_time;
-	/* time spent idling for this blkcg_gq */
-	struct blkg_stat		idle_time;
-	/* total time with empty current active q with other requests queued */
-	struct blkg_stat		empty_time;
-	/* fields after this shouldn't be cleared on stat reset */
-	uint64_t			start_group_wait_time;
-	uint64_t			start_idle_time;
-	uint64_t			start_empty_time;
-	uint16_t			flags;
-#endif	/* CONFIG_DEBUG_BLK_CGROUP */
-#endif	/* CONFIG_CFQ_GROUP_IOSCHED */
-};
-
-/* Per-cgroup data */
-struct cfq_group_data {
-	/* must be the first member */
-	struct blkcg_policy_data cpd;
-
-	unsigned int weight;
-	unsigned int leaf_weight;
+struct cfq_io_cq {
+	struct io_cq		icq;		/* must be the first member */
+	struct cfq_queue	*cfqq[2];
+	struct cfq_ttime	ttime;
+	int			ioprio;		/* the current ioprio */
 };
 
-/* This is per cgroup per device grouping structure */
-struct cfq_group {
-	/* must be the first member */
-	struct blkg_policy_data pd;
-
-	/* group service_tree member */
-	struct rb_node rb_node;
-
-	/* group service_tree key */
-	u64 vdisktime;
-
-	/*
-	 * The number of active cfqgs and sum of their weights under this
-	 * cfqg.  This covers this cfqg's leaf_weight and all children's
-	 * weights, but does not cover weights of further descendants.
-	 *
-	 * If a cfqg is on the service tree, it's active.  An active cfqg
-	 * also activates its parent and contributes to the children_weight
-	 * of the parent.
-	 */
-	int nr_active;
-	unsigned int children_weight;
-
-	/*
-	 * vfraction is the fraction of vdisktime that the tasks in this
-	 * cfqg are entitled to.  This is determined by compounding the
-	 * ratios walking up from this cfqg to the root.
-	 *
-	 * It is in fixed point w/ CFQ_SERVICE_SHIFT and the sum of all
-	 * vfractions on a service tree is approximately 1.  The sum may
-	 * deviate a bit due to rounding errors and fluctuations caused by
-	 * cfqgs entering and leaving the service tree.
-	 */
-	unsigned int vfraction;
-
-	/*
-	 * There are two weights - (internal) weight is the weight of this
-	 * cfqg against the sibling cfqgs.  leaf_weight is the wight of
-	 * this cfqg against the child cfqgs.  For the root cfqg, both
-	 * weights are kept in sync for backward compatibility.
-	 */
-	unsigned int weight;
-	unsigned int new_weight;
-	unsigned int dev_weight;
-
-	unsigned int leaf_weight;
-	unsigned int new_leaf_weight;
-	unsigned int dev_leaf_weight;
-
-	/* number of cfqq currently on this group */
-	int nr_cfqq;
+/*
+ * Per block device queue structure
+ */
+struct cfq_data {
+	struct request_queue *queue;
 
 	/*
-	 * Per group busy queues average. Useful for workload slice calc. We
-	 * create the array for each prio class but at run time it is used
-	 * only for RT and BE class and slot for IDLE class remains unused.
-	 * This is primarily done to avoid confusion and a gcc warning.
-	 */
-	unsigned int busy_queues_avg[CFQ_PRIO_NR];
-	/*
 	 * rr lists of queues with requests. We maintain service trees for
 	 * RT and BE classes. These trees are subdivided in subclasses
 	 * of SYNC, SYNC_NOIDLE and ASYNC based on workload type. For IDLE
@@ -289,47 +188,12 @@ struct cfq_group {
 	struct cfq_rb_root service_trees[2][3];
 	struct cfq_rb_root service_tree_idle;
 
-	unsigned long saved_wl_slice;
-	enum wl_type_t saved_wl_type;
-	enum wl_class_t saved_wl_class;
-
-	/* number of requests that are on the dispatch list or inside driver */
-	int dispatched;
-	struct cfq_ttime ttime;
-	struct cfqg_stats stats;	/* stats for this cfqg */
-
-	/* async queue for each priority case */
-	struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR];
-	struct cfq_queue *async_idle_cfqq;
-
-};
-
-struct cfq_io_cq {
-	struct io_cq		icq;		/* must be the first member */
-	struct cfq_queue	*cfqq[2];
-	struct cfq_ttime	ttime;
-	int			ioprio;		/* the current ioprio */
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-	uint64_t		blkcg_serial_nr; /* the current blkcg serial */
-#endif
-};
-
-/*
- * Per block device queue structure
- */
-struct cfq_data {
-	struct request_queue *queue;
-	/* Root service tree for cfq_groups */
-	struct cfq_rb_root grp_service_tree;
-	struct cfq_group *root_group;
-
 	/*
 	 * The priority currently being served
 	 */
 	enum wl_class_t serving_wl_class;
 	enum wl_type_t serving_wl_type;
 	unsigned long workload_expires;
-	struct cfq_group *serving_group;
 
 	unsigned int busy_queues;
 	unsigned int busy_sync_queues;
@@ -360,6 +224,10 @@ struct cfq_data {
 	struct cfq_queue *active_queue;
 	struct cfq_io_cq *active_cic;
 
+	/* async queue for each priority case */
+	struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR];
+	struct cfq_queue *async_idle_cfqq;
+
 	sector_t last_position;
 
 	/*
@@ -372,7 +240,6 @@ struct cfq_data {
 	unsigned int cfq_slice[2];
 	unsigned int cfq_slice_async_rq;
 	unsigned int cfq_slice_idle;
-	unsigned int cfq_group_idle;
 	unsigned int cfq_latency;
 	unsigned int cfq_target_latency;
 
@@ -384,22 +251,6 @@ struct cfq_data {
 	unsigned long last_delayed_sync;
 };
 
-static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd);
-static void cfq_put_queue(struct cfq_queue *cfqq);
-
-static struct cfq_rb_root *st_for(struct cfq_group *cfqg,
-					    enum wl_class_t class,
-					    enum wl_type_t type)
-{
-	if (!cfqg)
-		return NULL;
-
-	if (class == IDLE_WORKLOAD)
-		return &cfqg->service_tree_idle;
-
-	return &cfqg->service_trees[class][type];
-}
-
 enum cfqq_state_flags {
 	CFQ_CFQQ_FLAG_on_rr = 0,	/* on round-robin busy list */
 	CFQ_CFQQ_FLAG_wait_request,	/* waiting for a request */
@@ -439,385 +290,34 @@ CFQ_CFQQ_FNS(sync);
 CFQ_CFQQ_FNS(wait_busy);
 #undef CFQ_CFQQ_FNS
 
-#if defined(CONFIG_CFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP)
-
-/* cfqg stats flags */
-enum cfqg_stats_flags {
-	CFQG_stats_waiting = 0,
-	CFQG_stats_idling,
-	CFQG_stats_empty,
-};
-
-#define CFQG_FLAG_FNS(name)						\
-static inline void cfqg_stats_mark_##name(struct cfqg_stats *stats)	\
-{									\
-	stats->flags |= (1 << CFQG_stats_##name);			\
-}									\
-static inline void cfqg_stats_clear_##name(struct cfqg_stats *stats)	\
-{									\
-	stats->flags &= ~(1 << CFQG_stats_##name);			\
-}									\
-static inline int cfqg_stats_##name(struct cfqg_stats *stats)		\
-{									\
-	return (stats->flags & (1 << CFQG_stats_##name)) != 0;		\
-}									\
-
-CFQG_FLAG_FNS(waiting)
-CFQG_FLAG_FNS(idling)
-CFQG_FLAG_FNS(empty)
-#undef CFQG_FLAG_FNS
-
-/* This should be called with the queue_lock held. */
-static void cfqg_stats_update_group_wait_time(struct cfqg_stats *stats)
-{
-	unsigned long long now;
-
-	if (!cfqg_stats_waiting(stats))
-		return;
-
-	now = sched_clock();
-	if (time_after64(now, stats->start_group_wait_time))
-		blkg_stat_add(&stats->group_wait_time,
-			      now - stats->start_group_wait_time);
-	cfqg_stats_clear_waiting(stats);
-}
-
-/* This should be called with the queue_lock held. */
-static void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg,
-						 struct cfq_group *curr_cfqg)
-{
-	struct cfqg_stats *stats = &cfqg->stats;
-
-	if (cfqg_stats_waiting(stats))
-		return;
-	if (cfqg == curr_cfqg)
-		return;
-	stats->start_group_wait_time = sched_clock();
-	cfqg_stats_mark_waiting(stats);
-}
-
-/* This should be called with the queue_lock held. */
-static void cfqg_stats_end_empty_time(struct cfqg_stats *stats)
-{
-	unsigned long long now;
-
-	if (!cfqg_stats_empty(stats))
-		return;
-
-	now = sched_clock();
-	if (time_after64(now, stats->start_empty_time))
-		blkg_stat_add(&stats->empty_time,
-			      now - stats->start_empty_time);
-	cfqg_stats_clear_empty(stats);
-}
-
-static void cfqg_stats_update_dequeue(struct cfq_group *cfqg)
-{
-	blkg_stat_add(&cfqg->stats.dequeue, 1);
-}
-
-static void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg)
-{
-	struct cfqg_stats *stats = &cfqg->stats;
-
-	if (blkg_rwstat_total(&stats->queued))
-		return;
-
-	/*
-	 * group is already marked empty. This can happen if cfqq got new
-	 * request in parent group and moved to this group while being added
-	 * to service tree. Just ignore the event and move on.
-	 */
-	if (cfqg_stats_empty(stats))
-		return;
-
-	stats->start_empty_time = sched_clock();
-	cfqg_stats_mark_empty(stats);
-}
-
-static void cfqg_stats_update_idle_time(struct cfq_group *cfqg)
-{
-	struct cfqg_stats *stats = &cfqg->stats;
-
-	if (cfqg_stats_idling(stats)) {
-		unsigned long long now = sched_clock();
-
-		if (time_after64(now, stats->start_idle_time))
-			blkg_stat_add(&stats->idle_time,
-				      now - stats->start_idle_time);
-		cfqg_stats_clear_idling(stats);
-	}
-}
-
-static void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg)
-{
-	struct cfqg_stats *stats = &cfqg->stats;
-
-	BUG_ON(cfqg_stats_idling(stats));
-
-	stats->start_idle_time = sched_clock();
-	cfqg_stats_mark_idling(stats);
-}
-
-static void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg)
-{
-	struct cfqg_stats *stats = &cfqg->stats;
-
-	blkg_stat_add(&stats->avg_queue_size_sum,
-		      blkg_rwstat_total(&stats->queued));
-	blkg_stat_add(&stats->avg_queue_size_samples, 1);
-	cfqg_stats_update_group_wait_time(stats);
-}
-
-#else	/* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */
-
-static inline void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, struct cfq_group *curr_cfqg) { }
-static inline void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { }
-static inline void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { }
-static inline void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) { }
-static inline void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { }
-static inline void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) { }
-static inline void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { }
-
-#endif	/* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */
-
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-
-static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd)
-{
-	return pd ? container_of(pd, struct cfq_group, pd) : NULL;
-}
-
-static struct cfq_group_data
-*cpd_to_cfqgd(struct blkcg_policy_data *cpd)
-{
-	return cpd ? container_of(cpd, struct cfq_group_data, cpd) : NULL;
-}
-
-static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg)
-{
-	return pd_to_blkg(&cfqg->pd);
-}
-
-static struct blkcg_policy blkcg_policy_cfq;
-
-static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg)
-{
-	return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq));
-}
-
-static struct cfq_group_data *blkcg_to_cfqgd(struct blkcg *blkcg)
-{
-	return cpd_to_cfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_cfq));
-}
-
-static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg)
-{
-	struct blkcg_gq *pblkg = cfqg_to_blkg(cfqg)->parent;
-
-	return pblkg ? blkg_to_cfqg(pblkg) : NULL;
-}
-
-static inline bool cfqg_is_descendant(struct cfq_group *cfqg,
-				      struct cfq_group *ancestor)
-{
-	return cgroup_is_descendant(cfqg_to_blkg(cfqg)->blkcg->css.cgroup,
-				    cfqg_to_blkg(ancestor)->blkcg->css.cgroup);
-}
-
-static inline void cfqg_get(struct cfq_group *cfqg)
-{
-	return blkg_get(cfqg_to_blkg(cfqg));
-}
-
-static inline void cfqg_put(struct cfq_group *cfqg)
-{
-	return blkg_put(cfqg_to_blkg(cfqg));
-}
-
-#define cfq_log_cfqq(cfqd, cfqq, fmt, args...)	do {			\
-	char __pbuf[128];						\
-									\
-	blkg_path(cfqg_to_blkg((cfqq)->cfqg), __pbuf, sizeof(__pbuf));	\
-	blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c %s " fmt, (cfqq)->pid, \
-			cfq_cfqq_sync((cfqq)) ? 'S' : 'A',		\
-			cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\
-			  __pbuf, ##args);				\
-} while (0)
-
-#define cfq_log_cfqg(cfqd, cfqg, fmt, args...)	do {			\
-	char __pbuf[128];						\
-									\
-	blkg_path(cfqg_to_blkg(cfqg), __pbuf, sizeof(__pbuf));		\
-	blk_add_trace_msg((cfqd)->queue, "%s " fmt, __pbuf, ##args);	\
-} while (0)
-
-static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
-					    struct cfq_group *curr_cfqg, int rw)
-{
-	blkg_rwstat_add(&cfqg->stats.queued, rw, 1);
-	cfqg_stats_end_empty_time(&cfqg->stats);
-	cfqg_stats_set_start_group_wait_time(cfqg, curr_cfqg);
-}
-
-static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg,
-			unsigned long time, unsigned long unaccounted_time)
-{
-	blkg_stat_add(&cfqg->stats.time, time);
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-	blkg_stat_add(&cfqg->stats.unaccounted_time, unaccounted_time);
-#endif
-}
-
-static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int rw)
-{
-	blkg_rwstat_add(&cfqg->stats.queued, rw, -1);
-}
-
-static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int rw)
-{
-	blkg_rwstat_add(&cfqg->stats.merged, rw, 1);
-}
-
-static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
-			uint64_t start_time, uint64_t io_start_time, int rw)
-{
-	struct cfqg_stats *stats = &cfqg->stats;
-	unsigned long long now = sched_clock();
-
-	if (time_after64(now, io_start_time))
-		blkg_rwstat_add(&stats->service_time, rw, now - io_start_time);
-	if (time_after64(io_start_time, start_time))
-		blkg_rwstat_add(&stats->wait_time, rw,
-				io_start_time - start_time);
-}
-
-/* @stats = 0 */
-static void cfqg_stats_reset(struct cfqg_stats *stats)
-{
-	/* queued stats shouldn't be cleared */
-	blkg_rwstat_reset(&stats->merged);
-	blkg_rwstat_reset(&stats->service_time);
-	blkg_rwstat_reset(&stats->wait_time);
-	blkg_stat_reset(&stats->time);
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-	blkg_stat_reset(&stats->unaccounted_time);
-	blkg_stat_reset(&stats->avg_queue_size_sum);
-	blkg_stat_reset(&stats->avg_queue_size_samples);
-	blkg_stat_reset(&stats->dequeue);
-	blkg_stat_reset(&stats->group_wait_time);
-	blkg_stat_reset(&stats->idle_time);
-	blkg_stat_reset(&stats->empty_time);
-#endif
-}
-
-/* @to += @from */
-static void cfqg_stats_add_aux(struct cfqg_stats *to, struct cfqg_stats *from)
-{
-	/* queued stats shouldn't be cleared */
-	blkg_rwstat_add_aux(&to->merged, &from->merged);
-	blkg_rwstat_add_aux(&to->service_time, &from->service_time);
-	blkg_rwstat_add_aux(&to->wait_time, &from->wait_time);
-	blkg_stat_add_aux(&from->time, &from->time);
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-	blkg_stat_add_aux(&to->unaccounted_time, &from->unaccounted_time);
-	blkg_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum);
-	blkg_stat_add_aux(&to->avg_queue_size_samples, &from->avg_queue_size_samples);
-	blkg_stat_add_aux(&to->dequeue, &from->dequeue);
-	blkg_stat_add_aux(&to->group_wait_time, &from->group_wait_time);
-	blkg_stat_add_aux(&to->idle_time, &from->idle_time);
-	blkg_stat_add_aux(&to->empty_time, &from->empty_time);
-#endif
-}
-
-/*
- * Transfer @cfqg's stats to its parent's aux counts so that the ancestors'
- * recursive stats can still account for the amount used by this cfqg after
- * it's gone.
- */
-static void cfqg_stats_xfer_dead(struct cfq_group *cfqg)
-{
-	struct cfq_group *parent = cfqg_parent(cfqg);
-
-	lockdep_assert_held(cfqg_to_blkg(cfqg)->q->queue_lock);
-
-	if (unlikely(!parent))
-		return;
-
-	cfqg_stats_add_aux(&parent->stats, &cfqg->stats);
-	cfqg_stats_reset(&cfqg->stats);
-}
-
-#else	/* CONFIG_CFQ_GROUP_IOSCHED */
-
-static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) { return NULL; }
-static inline bool cfqg_is_descendant(struct cfq_group *cfqg,
-				      struct cfq_group *ancestor)
-{
-	return true;
-}
-static inline void cfqg_get(struct cfq_group *cfqg) { }
-static inline void cfqg_put(struct cfq_group *cfqg) { }
-
 #define cfq_log_cfqq(cfqd, cfqq, fmt, args...)	\
 	blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c " fmt, (cfqq)->pid,	\
 			cfq_cfqq_sync((cfqq)) ? 'S' : 'A',		\
 			cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\
 				##args)
-#define cfq_log_cfqg(cfqd, cfqg, fmt, args...)		do {} while (0)
-
-static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
-			struct cfq_group *curr_cfqg, int rw) { }
-static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg,
-			unsigned long time, unsigned long unaccounted_time) { }
-static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int rw) { }
-static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int rw) { }
-static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
-			uint64_t start_time, uint64_t io_start_time, int rw) { }
-
-#endif	/* CONFIG_CFQ_GROUP_IOSCHED */
-
 #define cfq_log(cfqd, fmt, args...)	\
 	blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args)
 
-/* Traverses through cfq group service trees */
-#define for_each_cfqg_st(cfqg, i, j, st) \
+/* Traverses through cfq service trees */
+#define for_each_st(cfqd, i, j, st) \
 	for (i = 0; i <= IDLE_WORKLOAD; i++) \
-		for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\
-			: &cfqg->service_tree_idle; \
+		for (j = 0, st = i < IDLE_WORKLOAD ? &cfqd->service_trees[i][j]\
+			: &cfqd->service_tree_idle; \
 			(i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \
 			(i == IDLE_WORKLOAD && j == 0); \
 			j++, st = i < IDLE_WORKLOAD ? \
-			&cfqg->service_trees[i][j]: NULL) \
+			&cfqd->service_trees[i][j] : NULL) \
 
 static inline bool cfq_io_thinktime_big(struct cfq_data *cfqd,
-	struct cfq_ttime *ttime, bool group_idle)
+	struct cfq_ttime *ttime)
 {
 	unsigned long slice;
 	if (!sample_valid(ttime->ttime_samples))
 		return false;
-	if (group_idle)
-		slice = cfqd->cfq_group_idle;
-	else
-		slice = cfqd->cfq_slice_idle;
+	slice = cfqd->cfq_slice_idle;
 	return ttime->ttime_mean > slice;
 }
 
-static inline bool iops_mode(struct cfq_data *cfqd)
-{
-	/*
-	 * If we are not idling on queues and it is a NCQ drive, parallel
-	 * execution of requests is on and measuring time is not possible
-	 * in most of the cases until and unless we drive shallower queue
-	 * depths and that becomes a performance bottleneck. In such cases
-	 * switch to start providing fairness in terms of number of IOs.
-	 */
-	if (!cfqd->cfq_slice_idle && cfqd->hw_tag)
-		return true;
-	else
-		return false;
-}
-
 static inline enum wl_class_t cfqq_class(struct cfq_queue *cfqq)
 {
 	if (cfq_class_idle(cfqq))
@@ -837,23 +337,21 @@ static enum wl_type_t cfqq_type(struct cfq_queue *cfqq)
 	return SYNC_WORKLOAD;
 }
 
-static inline int cfq_group_busy_queues_wl(enum wl_class_t wl_class,
-					struct cfq_data *cfqd,
-					struct cfq_group *cfqg)
+static inline int cfq_busy_queues_wl(enum wl_class_t wl_class,
+					struct cfq_data *cfqd)
 {
 	if (wl_class == IDLE_WORKLOAD)
-		return cfqg->service_tree_idle.count;
+		return cfqd->service_tree_idle.count;
 
-	return cfqg->service_trees[wl_class][ASYNC_WORKLOAD].count +
-		cfqg->service_trees[wl_class][SYNC_NOIDLE_WORKLOAD].count +
-		cfqg->service_trees[wl_class][SYNC_WORKLOAD].count;
+	return cfqd->service_trees[wl_class][ASYNC_WORKLOAD].count +
+		cfqd->service_trees[wl_class][SYNC_NOIDLE_WORKLOAD].count +
+		cfqd->service_trees[wl_class][SYNC_WORKLOAD].count;
 }
 
-static inline int cfqg_busy_async_queues(struct cfq_data *cfqd,
-					struct cfq_group *cfqg)
+static inline int cfq_busy_async_queues(struct cfq_data *cfqd)
 {
-	return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count +
-		cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count;
+	return cfqd->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count +
+		cfqd->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count;
 }
 
 static void cfq_dispatch_insert(struct request_queue *, struct request *);
@@ -932,29 +430,6 @@ cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 	return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio);
 }
 
-/**
- * cfqg_scale_charge - scale disk time charge according to cfqg weight
- * @charge: disk time being charged
- * @vfraction: vfraction of the cfqg, fixed point w/ CFQ_SERVICE_SHIFT
- *
- * Scale @charge according to @vfraction, which is in range (0, 1].  The
- * scaling is inversely proportional.
- *
- * scaled = charge / vfraction
- *
- * The result is also in fixed point w/ CFQ_SERVICE_SHIFT.
- */
-static inline u64 cfqg_scale_charge(unsigned long charge,
-				    unsigned int vfraction)
-{
-	u64 c = charge << CFQ_SERVICE_SHIFT;	/* make it fixed point */
-
-	/* charge / vfraction */
-	c <<= CFQ_SERVICE_SHIFT;
-	do_div(c, vfraction);
-	return c;
-}
-
 static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime)
 {
 	s64 delta = (s64)(vdisktime - min_vdisktime);
@@ -973,72 +448,10 @@ static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime)
 	return min_vdisktime;
 }
 
-static void update_min_vdisktime(struct cfq_rb_root *st)
-{
-	struct cfq_group *cfqg;
-
-	if (st->left) {
-		cfqg = rb_entry_cfqg(st->left);
-		st->min_vdisktime = max_vdisktime(st->min_vdisktime,
-						  cfqg->vdisktime);
-	}
-}
-
-/*
- * get averaged number of queues of RT/BE priority.
- * average is updated, with a formula that gives more weight to higher numbers,
- * to quickly follows sudden increases and decrease slowly
- */
-
-static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd,
-					struct cfq_group *cfqg, bool rt)
-{
-	unsigned min_q, max_q;
-	unsigned mult  = cfq_hist_divisor - 1;
-	unsigned round = cfq_hist_divisor / 2;
-	unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg);
-
-	min_q = min(cfqg->busy_queues_avg[rt], busy);
-	max_q = max(cfqg->busy_queues_avg[rt], busy);
-	cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) /
-		cfq_hist_divisor;
-	return cfqg->busy_queues_avg[rt];
-}
-
-static inline unsigned
-cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg)
-{
-	return cfqd->cfq_target_latency * cfqg->vfraction >> CFQ_SERVICE_SHIFT;
-}
-
 static inline unsigned
 cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
-	unsigned slice = cfq_prio_to_slice(cfqd, cfqq);
-	if (cfqd->cfq_latency) {
-		/*
-		 * interested queues (we consider only the ones with the same
-		 * priority class in the cfq group)
-		 */
-		unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg,
-						cfq_class_rt(cfqq));
-		unsigned sync_slice = cfqd->cfq_slice[1];
-		unsigned expect_latency = sync_slice * iq;
-		unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg);
-
-		if (expect_latency > group_slice) {
-			unsigned base_low_slice = 2 * cfqd->cfq_slice_idle;
-			/* scale low_slice according to IO priority
-			 * and sync vs async */
-			unsigned low_slice =
-				min(slice, base_low_slice * slice / sync_slice);
-			/* the adapted slice value is scaled to fit all iqs
-			 * into the target latency */
-			slice = max(slice * group_slice / expect_latency,
-				    low_slice);
-		}
-	}
-	return slice;
+	return cfq_prio_to_slice(cfqd, cfqq);
 }
 
 static inline void
@@ -1128,1067 +541,127 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2,
 	switch (wrap) {
 	case 0: /* common case for CFQ: rq1 and rq2 not wrapped */
 		if (d1 < d2)
-			return rq1;
-		else if (d2 < d1)
-			return rq2;
-		else {
-			if (s1 >= s2)
-				return rq1;
-			else
-				return rq2;
-		}
-
-	case CFQ_RQ2_WRAP:
-		return rq1;
-	case CFQ_RQ1_WRAP:
-		return rq2;
-	case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */
-	default:
-		/*
-		 * Since both rqs are wrapped,
-		 * start with the one that's further behind head
-		 * (--> only *one* back seek required),
-		 * since back seek takes more time than forward.
-		 */
-		if (s1 <= s2)
-			return rq1;
-		else
-			return rq2;
-	}
-}
-
-/*
- * The below is leftmost cache rbtree addon
- */
-static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
-{
-	/* Service tree is empty */
-	if (!root->count)
-		return NULL;
-
-	if (!root->left)
-		root->left = rb_first(&root->rb);
-
-	if (root->left)
-		return rb_entry(root->left, struct cfq_queue, rb_node);
-
-	return NULL;
-}
-
-static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root)
-{
-	if (!root->left)
-		root->left = rb_first(&root->rb);
-
-	if (root->left)
-		return rb_entry_cfqg(root->left);
-
-	return NULL;
-}
-
-static void rb_erase_init(struct rb_node *n, struct rb_root *root)
-{
-	rb_erase(n, root);
-	RB_CLEAR_NODE(n);
-}
-
-static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root)
-{
-	if (root->left == n)
-		root->left = NULL;
-	rb_erase_init(n, &root->rb);
-	--root->count;
-}
-
-/*
- * would be nice to take fifo expire time into account as well
- */
-static struct request *
-cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
-		  struct request *last)
-{
-	struct rb_node *rbnext = rb_next(&last->rb_node);
-	struct rb_node *rbprev = rb_prev(&last->rb_node);
-	struct request *next = NULL, *prev = NULL;
-
-	BUG_ON(RB_EMPTY_NODE(&last->rb_node));
-
-	if (rbprev)
-		prev = rb_entry_rq(rbprev);
-
-	if (rbnext)
-		next = rb_entry_rq(rbnext);
-	else {
-		rbnext = rb_first(&cfqq->sort_list);
-		if (rbnext && rbnext != &last->rb_node)
-			next = rb_entry_rq(rbnext);
-	}
-
-	return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last));
-}
-
-static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
-				      struct cfq_queue *cfqq)
-{
-	/*
-	 * just an approximation, should be ok.
-	 */
-	return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) -
-		       cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio));
-}
-
-static inline s64
-cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg)
-{
-	return cfqg->vdisktime - st->min_vdisktime;
-}
-
-static void
-__cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
-{
-	struct rb_node **node = &st->rb.rb_node;
-	struct rb_node *parent = NULL;
-	struct cfq_group *__cfqg;
-	s64 key = cfqg_key(st, cfqg);
-	int left = 1;
-
-	while (*node != NULL) {
-		parent = *node;
-		__cfqg = rb_entry_cfqg(parent);
-
-		if (key < cfqg_key(st, __cfqg))
-			node = &parent->rb_left;
-		else {
-			node = &parent->rb_right;
-			left = 0;
-		}
-	}
-
-	if (left)
-		st->left = &cfqg->rb_node;
-
-	rb_link_node(&cfqg->rb_node, parent, node);
-	rb_insert_color(&cfqg->rb_node, &st->rb);
-}
-
-/*
- * This has to be called only on activation of cfqg
- */
-static void
-cfq_update_group_weight(struct cfq_group *cfqg)
-{
-	if (cfqg->new_weight) {
-		cfqg->weight = cfqg->new_weight;
-		cfqg->new_weight = 0;
-	}
-}
-
-static void
-cfq_update_group_leaf_weight(struct cfq_group *cfqg)
-{
-	BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node));
-
-	if (cfqg->new_leaf_weight) {
-		cfqg->leaf_weight = cfqg->new_leaf_weight;
-		cfqg->new_leaf_weight = 0;
-	}
-}
-
-static void
-cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
-{
-	unsigned int vfr = 1 << CFQ_SERVICE_SHIFT;	/* start with 1 */
-	struct cfq_group *pos = cfqg;
-	struct cfq_group *parent;
-	bool propagate;
-
-	/* add to the service tree */
-	BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node));
-
-	/*
-	 * Update leaf_weight.  We cannot update weight at this point
-	 * because cfqg might already have been activated and is
-	 * contributing its current weight to the parent's child_weight.
-	 */
-	cfq_update_group_leaf_weight(cfqg);
-	__cfq_group_service_tree_add(st, cfqg);
-
-	/*
-	 * Activate @cfqg and calculate the portion of vfraction @cfqg is
-	 * entitled to.  vfraction is calculated by walking the tree
-	 * towards the root calculating the fraction it has at each level.
-	 * The compounded ratio is how much vfraction @cfqg owns.
-	 *
-	 * Start with the proportion tasks in this cfqg has against active
-	 * children cfqgs - its leaf_weight against children_weight.
-	 */
-	propagate = !pos->nr_active++;
-	pos->children_weight += pos->leaf_weight;
-	vfr = vfr * pos->leaf_weight / pos->children_weight;
-
-	/*
-	 * Compound ->weight walking up the tree.  Both activation and
-	 * vfraction calculation are done in the same loop.  Propagation
-	 * stops once an already activated node is met.  vfraction
-	 * calculation should always continue to the root.
-	 */
-	while ((parent = cfqg_parent(pos))) {
-		if (propagate) {
-			cfq_update_group_weight(pos);
-			propagate = !parent->nr_active++;
-			parent->children_weight += pos->weight;
-		}
-		vfr = vfr * pos->weight / parent->children_weight;
-		pos = parent;
-	}
-
-	cfqg->vfraction = max_t(unsigned, vfr, 1);
-}
-
-static void
-cfq_group_notify_queue_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
-{
-	struct cfq_rb_root *st = &cfqd->grp_service_tree;
-	struct cfq_group *__cfqg;
-	struct rb_node *n;
-
-	cfqg->nr_cfqq++;
-	if (!RB_EMPTY_NODE(&cfqg->rb_node))
-		return;
-
-	/*
-	 * Currently put the group at the end. Later implement something
-	 * so that groups get lesser vtime based on their weights, so that
-	 * if group does not loose all if it was not continuously backlogged.
-	 */
-	n = rb_last(&st->rb);
-	if (n) {
-		__cfqg = rb_entry_cfqg(n);
-		cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY;
-	} else
-		cfqg->vdisktime = st->min_vdisktime;
-	cfq_group_service_tree_add(st, cfqg);
-}
-
-static void
-cfq_group_service_tree_del(struct cfq_rb_root *st, struct cfq_group *cfqg)
-{
-	struct cfq_group *pos = cfqg;
-	bool propagate;
-
-	/*
-	 * Undo activation from cfq_group_service_tree_add().  Deactivate
-	 * @cfqg and propagate deactivation upwards.
-	 */
-	propagate = !--pos->nr_active;
-	pos->children_weight -= pos->leaf_weight;
-
-	while (propagate) {
-		struct cfq_group *parent = cfqg_parent(pos);
-
-		/* @pos has 0 nr_active at this point */
-		WARN_ON_ONCE(pos->children_weight);
-		pos->vfraction = 0;
-
-		if (!parent)
-			break;
-
-		propagate = !--parent->nr_active;
-		parent->children_weight -= pos->weight;
-		pos = parent;
-	}
-
-	/* remove from the service tree */
-	if (!RB_EMPTY_NODE(&cfqg->rb_node))
-		cfq_rb_erase(&cfqg->rb_node, st);
-}
-
-static void
-cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
-{
-	struct cfq_rb_root *st = &cfqd->grp_service_tree;
-
-	BUG_ON(cfqg->nr_cfqq < 1);
-	cfqg->nr_cfqq--;
-
-	/* If there are other cfq queues under this group, don't delete it */
-	if (cfqg->nr_cfqq)
-		return;
-
-	cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
-	cfq_group_service_tree_del(st, cfqg);
-	cfqg->saved_wl_slice = 0;
-	cfqg_stats_update_dequeue(cfqg);
-}
-
-static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq,
-						unsigned int *unaccounted_time)
-{
-	unsigned int slice_used;
-
-	/*
-	 * Queue got expired before even a single request completed or
-	 * got expired immediately after first request completion.
-	 */
-	if (!cfqq->slice_start || cfqq->slice_start == jiffies) {
-		/*
-		 * Also charge the seek time incurred to the group, otherwise
-		 * if there are mutiple queues in the group, each can dispatch
-		 * a single request on seeky media and cause lots of seek time
-		 * and group will never know it.
-		 */
-		slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start),
-					1);
-	} else {
-		slice_used = jiffies - cfqq->slice_start;
-		if (slice_used > cfqq->allocated_slice) {
-			*unaccounted_time = slice_used - cfqq->allocated_slice;
-			slice_used = cfqq->allocated_slice;
-		}
-		if (time_after(cfqq->slice_start, cfqq->dispatch_start))
-			*unaccounted_time += cfqq->slice_start -
-					cfqq->dispatch_start;
-	}
-
-	return slice_used;
-}
-
-static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
-				struct cfq_queue *cfqq)
-{
-	struct cfq_rb_root *st = &cfqd->grp_service_tree;
-	unsigned int used_sl, charge, unaccounted_sl = 0;
-	int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg)
-			- cfqg->service_tree_idle.count;
-	unsigned int vfr;
-
-	BUG_ON(nr_sync < 0);
-	used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl);
-
-	if (iops_mode(cfqd))
-		charge = cfqq->slice_dispatch;
-	else if (!cfq_cfqq_sync(cfqq) && !nr_sync)
-		charge = cfqq->allocated_slice;
-
-	/*
-	 * Can't update vdisktime while on service tree and cfqg->vfraction
-	 * is valid only while on it.  Cache vfr, leave the service tree,
-	 * update vdisktime and go back on.  The re-addition to the tree
-	 * will also update the weights as necessary.
-	 */
-	vfr = cfqg->vfraction;
-	cfq_group_service_tree_del(st, cfqg);
-	cfqg->vdisktime += cfqg_scale_charge(charge, vfr);
-	cfq_group_service_tree_add(st, cfqg);
-
-	/* This group is being expired. Save the context */
-	if (time_after(cfqd->workload_expires, jiffies)) {
-		cfqg->saved_wl_slice = cfqd->workload_expires
-						- jiffies;
-		cfqg->saved_wl_type = cfqd->serving_wl_type;
-		cfqg->saved_wl_class = cfqd->serving_wl_class;
-	} else
-		cfqg->saved_wl_slice = 0;
-
-	cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
-					st->min_vdisktime);
-	cfq_log_cfqq(cfqq->cfqd, cfqq,
-		     "sl_used=%u disp=%u charge=%u iops=%u sect=%lu",
-		     used_sl, cfqq->slice_dispatch, charge,
-		     iops_mode(cfqd), cfqq->nr_sectors);
-	cfqg_stats_update_timeslice_used(cfqg, used_sl, unaccounted_sl);
-	cfqg_stats_set_start_empty_time(cfqg);
-}
-
-/**
- * cfq_init_cfqg_base - initialize base part of a cfq_group
- * @cfqg: cfq_group to initialize
- *
- * Initialize the base part which is used whether %CONFIG_CFQ_GROUP_IOSCHED
- * is enabled or not.
- */
-static void cfq_init_cfqg_base(struct cfq_group *cfqg)
-{
-	struct cfq_rb_root *st;
-	int i, j;
-
-	for_each_cfqg_st(cfqg, i, j, st)
-		*st = CFQ_RB_ROOT;
-	RB_CLEAR_NODE(&cfqg->rb_node);
-
-	cfqg->ttime.last_end_request = jiffies;
-}
-
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val,
-			    bool on_dfl, bool reset_dev, bool is_leaf_weight);
-
-static void cfqg_stats_exit(struct cfqg_stats *stats)
-{
-	blkg_rwstat_exit(&stats->merged);
-	blkg_rwstat_exit(&stats->service_time);
-	blkg_rwstat_exit(&stats->wait_time);
-	blkg_rwstat_exit(&stats->queued);
-	blkg_stat_exit(&stats->time);
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-	blkg_stat_exit(&stats->unaccounted_time);
-	blkg_stat_exit(&stats->avg_queue_size_sum);
-	blkg_stat_exit(&stats->avg_queue_size_samples);
-	blkg_stat_exit(&stats->dequeue);
-	blkg_stat_exit(&stats->group_wait_time);
-	blkg_stat_exit(&stats->idle_time);
-	blkg_stat_exit(&stats->empty_time);
-#endif
-}
-
-static int cfqg_stats_init(struct cfqg_stats *stats, gfp_t gfp)
-{
-	if (blkg_rwstat_init(&stats->merged, gfp) ||
-	    blkg_rwstat_init(&stats->service_time, gfp) ||
-	    blkg_rwstat_init(&stats->wait_time, gfp) ||
-	    blkg_rwstat_init(&stats->queued, gfp) ||
-	    blkg_stat_init(&stats->time, gfp))
-		goto err;
-
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-	if (blkg_stat_init(&stats->unaccounted_time, gfp) ||
-	    blkg_stat_init(&stats->avg_queue_size_sum, gfp) ||
-	    blkg_stat_init(&stats->avg_queue_size_samples, gfp) ||
-	    blkg_stat_init(&stats->dequeue, gfp) ||
-	    blkg_stat_init(&stats->group_wait_time, gfp) ||
-	    blkg_stat_init(&stats->idle_time, gfp) ||
-	    blkg_stat_init(&stats->empty_time, gfp))
-		goto err;
-#endif
-	return 0;
-err:
-	cfqg_stats_exit(stats);
-	return -ENOMEM;
-}
-
-static struct blkcg_policy_data *cfq_cpd_alloc(gfp_t gfp)
-{
-	struct cfq_group_data *cgd;
-
-	cgd = kzalloc(sizeof(*cgd), GFP_KERNEL);
-	if (!cgd)
-		return NULL;
-	return &cgd->cpd;
-}
-
-static void cfq_cpd_init(struct blkcg_policy_data *cpd)
-{
-	struct cfq_group_data *cgd = cpd_to_cfqgd(cpd);
-	unsigned int weight = cgroup_subsys_on_dfl(io_cgrp_subsys) ?
-			      CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL;
-
-	if (cpd_to_blkcg(cpd) == &blkcg_root)
-		weight *= 2;
-
-	cgd->weight = weight;
-	cgd->leaf_weight = weight;
-}
-
-static void cfq_cpd_free(struct blkcg_policy_data *cpd)
-{
-	kfree(cpd_to_cfqgd(cpd));
-}
-
-static void cfq_cpd_bind(struct blkcg_policy_data *cpd)
-{
-	struct blkcg *blkcg = cpd_to_blkcg(cpd);
-	bool on_dfl = cgroup_subsys_on_dfl(io_cgrp_subsys);
-	unsigned int weight = on_dfl ? CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL;
-
-	if (blkcg == &blkcg_root)
-		weight *= 2;
-
-	WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, false));
-	WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, true));
-}
-
-static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)
-{
-	struct cfq_group *cfqg;
-
-	cfqg = kzalloc_node(sizeof(*cfqg), gfp, node);
-	if (!cfqg)
-		return NULL;
-
-	cfq_init_cfqg_base(cfqg);
-	if (cfqg_stats_init(&cfqg->stats, gfp)) {
-		kfree(cfqg);
-		return NULL;
-	}
-
-	return &cfqg->pd;
-}
-
-static void cfq_pd_init(struct blkg_policy_data *pd)
-{
-	struct cfq_group *cfqg = pd_to_cfqg(pd);
-	struct cfq_group_data *cgd = blkcg_to_cfqgd(pd->blkg->blkcg);
-
-	cfqg->weight = cgd->weight;
-	cfqg->leaf_weight = cgd->leaf_weight;
-}
-
-static void cfq_pd_offline(struct blkg_policy_data *pd)
-{
-	struct cfq_group *cfqg = pd_to_cfqg(pd);
-	int i;
-
-	for (i = 0; i < IOPRIO_BE_NR; i++) {
-		if (cfqg->async_cfqq[0][i])
-			cfq_put_queue(cfqg->async_cfqq[0][i]);
-		if (cfqg->async_cfqq[1][i])
-			cfq_put_queue(cfqg->async_cfqq[1][i]);
-	}
-
-	if (cfqg->async_idle_cfqq)
-		cfq_put_queue(cfqg->async_idle_cfqq);
-
-	/*
-	 * @blkg is going offline and will be ignored by
-	 * blkg_[rw]stat_recursive_sum().  Transfer stats to the parent so
-	 * that they don't get lost.  If IOs complete after this point, the
-	 * stats for them will be lost.  Oh well...
-	 */
-	cfqg_stats_xfer_dead(cfqg);
-}
-
-static void cfq_pd_free(struct blkg_policy_data *pd)
-{
-	struct cfq_group *cfqg = pd_to_cfqg(pd);
-
-	cfqg_stats_exit(&cfqg->stats);
-	return kfree(cfqg);
-}
-
-static void cfq_pd_reset_stats(struct blkg_policy_data *pd)
-{
-	struct cfq_group *cfqg = pd_to_cfqg(pd);
-
-	cfqg_stats_reset(&cfqg->stats);
-}
-
-static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd,
-					 struct blkcg *blkcg)
-{
-	struct blkcg_gq *blkg;
-
-	blkg = blkg_lookup(blkcg, cfqd->queue);
-	if (likely(blkg))
-		return blkg_to_cfqg(blkg);
-	return NULL;
-}
-
-static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg)
-{
-	cfqq->cfqg = cfqg;
-	/* cfqq reference on cfqg */
-	cfqg_get(cfqg);
-}
-
-static u64 cfqg_prfill_weight_device(struct seq_file *sf,
-				     struct blkg_policy_data *pd, int off)
-{
-	struct cfq_group *cfqg = pd_to_cfqg(pd);
-
-	if (!cfqg->dev_weight)
-		return 0;
-	return __blkg_prfill_u64(sf, pd, cfqg->dev_weight);
-}
-
-static int cfqg_print_weight_device(struct seq_file *sf, void *v)
-{
-	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
-			  cfqg_prfill_weight_device, &blkcg_policy_cfq,
-			  0, false);
-	return 0;
-}
-
-static u64 cfqg_prfill_leaf_weight_device(struct seq_file *sf,
-					  struct blkg_policy_data *pd, int off)
-{
-	struct cfq_group *cfqg = pd_to_cfqg(pd);
-
-	if (!cfqg->dev_leaf_weight)
-		return 0;
-	return __blkg_prfill_u64(sf, pd, cfqg->dev_leaf_weight);
-}
-
-static int cfqg_print_leaf_weight_device(struct seq_file *sf, void *v)
-{
-	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
-			  cfqg_prfill_leaf_weight_device, &blkcg_policy_cfq,
-			  0, false);
-	return 0;
-}
-
-static int cfq_print_weight(struct seq_file *sf, void *v)
-{
-	struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
-	struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
-	unsigned int val = 0;
-
-	if (cgd)
-		val = cgd->weight;
-
-	seq_printf(sf, "%u\n", val);
-	return 0;
-}
-
-static int cfq_print_leaf_weight(struct seq_file *sf, void *v)
-{
-	struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
-	struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
-	unsigned int val = 0;
-
-	if (cgd)
-		val = cgd->leaf_weight;
-
-	seq_printf(sf, "%u\n", val);
-	return 0;
-}
-
-static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
-					char *buf, size_t nbytes, loff_t off,
-					bool on_dfl, bool is_leaf_weight)
-{
-	unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN;
-	unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX;
-	struct blkcg *blkcg = css_to_blkcg(of_css(of));
-	struct blkg_conf_ctx ctx;
-	struct cfq_group *cfqg;
-	struct cfq_group_data *cfqgd;
-	int ret;
-	u64 v;
-
-	ret = blkg_conf_prep(blkcg, &blkcg_policy_cfq, buf, &ctx);
-	if (ret)
-		return ret;
-
-	if (sscanf(ctx.body, "%llu", &v) == 1) {
-		/* require "default" on dfl */
-		ret = -ERANGE;
-		if (!v && on_dfl)
-			goto out_finish;
-	} else if (!strcmp(strim(ctx.body), "default")) {
-		v = 0;
-	} else {
-		ret = -EINVAL;
-		goto out_finish;
-	}
-
-	cfqg = blkg_to_cfqg(ctx.blkg);
-	cfqgd = blkcg_to_cfqgd(blkcg);
-
-	ret = -ERANGE;
-	if (!v || (v >= min && v <= max)) {
-		if (!is_leaf_weight) {
-			cfqg->dev_weight = v;
-			cfqg->new_weight = v ?: cfqgd->weight;
-		} else {
-			cfqg->dev_leaf_weight = v;
-			cfqg->new_leaf_weight = v ?: cfqgd->leaf_weight;
-		}
-		ret = 0;
-	}
-out_finish:
-	blkg_conf_finish(&ctx);
-	return ret ?: nbytes;
-}
-
-static ssize_t cfqg_set_weight_device(struct kernfs_open_file *of,
-				      char *buf, size_t nbytes, loff_t off)
-{
-	return __cfqg_set_weight_device(of, buf, nbytes, off, false, false);
-}
-
-static ssize_t cfqg_set_leaf_weight_device(struct kernfs_open_file *of,
-					   char *buf, size_t nbytes, loff_t off)
-{
-	return __cfqg_set_weight_device(of, buf, nbytes, off, false, true);
-}
-
-static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val,
-			    bool on_dfl, bool reset_dev, bool is_leaf_weight)
-{
-	unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN;
-	unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX;
-	struct blkcg *blkcg = css_to_blkcg(css);
-	struct blkcg_gq *blkg;
-	struct cfq_group_data *cfqgd;
-	int ret = 0;
-
-	if (val < min || val > max)
-		return -ERANGE;
-
-	spin_lock_irq(&blkcg->lock);
-	cfqgd = blkcg_to_cfqgd(blkcg);
-	if (!cfqgd) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	if (!is_leaf_weight)
-		cfqgd->weight = val;
-	else
-		cfqgd->leaf_weight = val;
-
-	hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
-		struct cfq_group *cfqg = blkg_to_cfqg(blkg);
-
-		if (!cfqg)
-			continue;
-
-		if (!is_leaf_weight) {
-			if (reset_dev)
-				cfqg->dev_weight = 0;
-			if (!cfqg->dev_weight)
-				cfqg->new_weight = cfqgd->weight;
-		} else {
-			if (reset_dev)
-				cfqg->dev_leaf_weight = 0;
-			if (!cfqg->dev_leaf_weight)
-				cfqg->new_leaf_weight = cfqgd->leaf_weight;
-		}
-	}
-
-out:
-	spin_unlock_irq(&blkcg->lock);
-	return ret;
-}
-
-static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
-			  u64 val)
-{
-	return __cfq_set_weight(css, val, false, false, false);
-}
-
-static int cfq_set_leaf_weight(struct cgroup_subsys_state *css,
-			       struct cftype *cft, u64 val)
-{
-	return __cfq_set_weight(css, val, false, false, true);
-}
-
-static int cfqg_print_stat(struct seq_file *sf, void *v)
-{
-	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat,
-			  &blkcg_policy_cfq, seq_cft(sf)->private, false);
-	return 0;
-}
-
-static int cfqg_print_rwstat(struct seq_file *sf, void *v)
-{
-	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat,
-			  &blkcg_policy_cfq, seq_cft(sf)->private, true);
-	return 0;
-}
-
-static u64 cfqg_prfill_stat_recursive(struct seq_file *sf,
-				      struct blkg_policy_data *pd, int off)
-{
-	u64 sum = blkg_stat_recursive_sum(pd_to_blkg(pd),
-					  &blkcg_policy_cfq, off);
-	return __blkg_prfill_u64(sf, pd, sum);
-}
+			return rq1;
+		else if (d2 < d1)
+			return rq2;
+		if (s1 >= s2)
+			return rq1;
+		else
+			return rq2;
 
-static u64 cfqg_prfill_rwstat_recursive(struct seq_file *sf,
-					struct blkg_policy_data *pd, int off)
-{
-	struct blkg_rwstat sum = blkg_rwstat_recursive_sum(pd_to_blkg(pd),
-							&blkcg_policy_cfq, off);
-	return __blkg_prfill_rwstat(sf, pd, &sum);
+	case CFQ_RQ2_WRAP:
+		return rq1;
+	case CFQ_RQ1_WRAP:
+		return rq2;
+	case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */
+	default:
+		/*
+		 * Since both rqs are wrapped,
+		 * start with the one that's further behind head
+		 * (--> only *one* back seek required),
+		 * since back seek takes more time than forward.
+		 */
+		if (s1 <= s2)
+			return rq1;
+		else
+			return rq2;
+	}
 }
 
-static int cfqg_print_stat_recursive(struct seq_file *sf, void *v)
+/*
+ * The below is leftmost cache rbtree addon
+ */
+static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
 {
-	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
-			  cfqg_prfill_stat_recursive, &blkcg_policy_cfq,
-			  seq_cft(sf)->private, false);
-	return 0;
-}
+	/* Service tree is empty */
+	if (!root->count)
+		return NULL;
 
-static int cfqg_print_rwstat_recursive(struct seq_file *sf, void *v)
-{
-	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
-			  cfqg_prfill_rwstat_recursive, &blkcg_policy_cfq,
-			  seq_cft(sf)->private, true);
-	return 0;
-}
+	if (!root->left)
+		root->left = rb_first(&root->rb);
 
-static u64 cfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd,
-			       int off)
-{
-	u64 sum = blkg_rwstat_total(&pd->blkg->stat_bytes);
+	if (root->left)
+		return rb_entry(root->left, struct cfq_queue, rb_node);
 
-	return __blkg_prfill_u64(sf, pd, sum >> 9);
+	return NULL;
 }
 
-static int cfqg_print_stat_sectors(struct seq_file *sf, void *v)
+static void rb_erase_init(struct rb_node *n, struct rb_root *root)
 {
-	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
-			  cfqg_prfill_sectors, &blkcg_policy_cfq, 0, false);
-	return 0;
+	rb_erase(n, root);
+	RB_CLEAR_NODE(n);
 }
 
-static u64 cfqg_prfill_sectors_recursive(struct seq_file *sf,
-					 struct blkg_policy_data *pd, int off)
+static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root)
 {
-	struct blkg_rwstat tmp = blkg_rwstat_recursive_sum(pd->blkg, NULL,
-					offsetof(struct blkcg_gq, stat_bytes));
-	u64 sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +
-		atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]);
-
-	return __blkg_prfill_u64(sf, pd, sum >> 9);
+	if (root->left == n)
+		root->left = NULL;
+	rb_erase_init(n, &root->rb);
+	--root->count;
 }
 
-static int cfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v)
+/*
+ * would be nice to take fifo expire time into account as well
+ */
+static struct request *
+cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+		  struct request *last)
 {
-	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
-			  cfqg_prfill_sectors_recursive, &blkcg_policy_cfq, 0,
-			  false);
-	return 0;
-}
+	struct rb_node *rbnext = rb_next(&last->rb_node);
+	struct rb_node *rbprev = rb_prev(&last->rb_node);
+	struct request *next = NULL, *prev = NULL;
 
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf,
-				      struct blkg_policy_data *pd, int off)
-{
-	struct cfq_group *cfqg = pd_to_cfqg(pd);
-	u64 samples = blkg_stat_read(&cfqg->stats.avg_queue_size_samples);
-	u64 v = 0;
+	if (rbprev)
+		prev = rb_entry_rq(rbprev);
 
-	if (samples) {
-		v = blkg_stat_read(&cfqg->stats.avg_queue_size_sum);
-		v = div64_u64(v, samples);
+	if (rbnext)
+		next = rb_entry_rq(rbnext);
+	else {
+		rbnext = rb_first(&cfqq->sort_list);
+		if (rbnext && rbnext != &last->rb_node)
+			next = rb_entry_rq(rbnext);
 	}
-	__blkg_prfill_u64(sf, pd, v);
-	return 0;
-}
 
-/* print avg_queue_size */
-static int cfqg_print_avg_queue_size(struct seq_file *sf, void *v)
-{
-	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
-			  cfqg_prfill_avg_queue_size, &blkcg_policy_cfq,
-			  0, false);
-	return 0;
+	return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last));
 }
-#endif	/* CONFIG_DEBUG_BLK_CGROUP */
-
-static struct cftype cfq_blkcg_legacy_files[] = {
-	/* on root, weight is mapped to leaf_weight */
-	{
-		.name = "weight_device",
-		.flags = CFTYPE_ONLY_ON_ROOT,
-		.seq_show = cfqg_print_leaf_weight_device,
-		.write = cfqg_set_leaf_weight_device,
-	},
-	{
-		.name = "weight",
-		.flags = CFTYPE_ONLY_ON_ROOT,
-		.seq_show = cfq_print_leaf_weight,
-		.write_u64 = cfq_set_leaf_weight,
-	},
-
-	/* no such mapping necessary for !roots */
-	{
-		.name = "weight_device",
-		.flags = CFTYPE_NOT_ON_ROOT,
-		.seq_show = cfqg_print_weight_device,
-		.write = cfqg_set_weight_device,
-	},
-	{
-		.name = "weight",
-		.flags = CFTYPE_NOT_ON_ROOT,
-		.seq_show = cfq_print_weight,
-		.write_u64 = cfq_set_weight,
-	},
-
-	{
-		.name = "leaf_weight_device",
-		.seq_show = cfqg_print_leaf_weight_device,
-		.write = cfqg_set_leaf_weight_device,
-	},
-	{
-		.name = "leaf_weight",
-		.seq_show = cfq_print_leaf_weight,
-		.write_u64 = cfq_set_leaf_weight,
-	},
-
-	/* statistics, covers only the tasks in the cfqg */
-	{
-		.name = "time",
-		.private = offsetof(struct cfq_group, stats.time),
-		.seq_show = cfqg_print_stat,
-	},
-	{
-		.name = "sectors",
-		.seq_show = cfqg_print_stat_sectors,
-	},
-	{
-		.name = "io_service_bytes",
-		.private = (unsigned long)&blkcg_policy_cfq,
-		.seq_show = blkg_print_stat_bytes,
-	},
-	{
-		.name = "io_serviced",
-		.private = (unsigned long)&blkcg_policy_cfq,
-		.seq_show = blkg_print_stat_ios,
-	},
-	{
-		.name = "io_service_time",
-		.private = offsetof(struct cfq_group, stats.service_time),
-		.seq_show = cfqg_print_rwstat,
-	},
-	{
-		.name = "io_wait_time",
-		.private = offsetof(struct cfq_group, stats.wait_time),
-		.seq_show = cfqg_print_rwstat,
-	},
-	{
-		.name = "io_merged",
-		.private = offsetof(struct cfq_group, stats.merged),
-		.seq_show = cfqg_print_rwstat,
-	},
-	{
-		.name = "io_queued",
-		.private = offsetof(struct cfq_group, stats.queued),
-		.seq_show = cfqg_print_rwstat,
-	},
-
-	/* the same statictics which cover the cfqg and its descendants */
-	{
-		.name = "time_recursive",
-		.private = offsetof(struct cfq_group, stats.time),
-		.seq_show = cfqg_print_stat_recursive,
-	},
-	{
-		.name = "sectors_recursive",
-		.seq_show = cfqg_print_stat_sectors_recursive,
-	},
-	{
-		.name = "io_service_bytes_recursive",
-		.private = (unsigned long)&blkcg_policy_cfq,
-		.seq_show = blkg_print_stat_bytes_recursive,
-	},
-	{
-		.name = "io_serviced_recursive",
-		.private = (unsigned long)&blkcg_policy_cfq,
-		.seq_show = blkg_print_stat_ios_recursive,
-	},
-	{
-		.name = "io_service_time_recursive",
-		.private = offsetof(struct cfq_group, stats.service_time),
-		.seq_show = cfqg_print_rwstat_recursive,
-	},
-	{
-		.name = "io_wait_time_recursive",
-		.private = offsetof(struct cfq_group, stats.wait_time),
-		.seq_show = cfqg_print_rwstat_recursive,
-	},
-	{
-		.name = "io_merged_recursive",
-		.private = offsetof(struct cfq_group, stats.merged),
-		.seq_show = cfqg_print_rwstat_recursive,
-	},
-	{
-		.name = "io_queued_recursive",
-		.private = offsetof(struct cfq_group, stats.queued),
-		.seq_show = cfqg_print_rwstat_recursive,
-	},
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-	{
-		.name = "avg_queue_size",
-		.seq_show = cfqg_print_avg_queue_size,
-	},
-	{
-		.name = "group_wait_time",
-		.private = offsetof(struct cfq_group, stats.group_wait_time),
-		.seq_show = cfqg_print_stat,
-	},
-	{
-		.name = "idle_time",
-		.private = offsetof(struct cfq_group, stats.idle_time),
-		.seq_show = cfqg_print_stat,
-	},
-	{
-		.name = "empty_time",
-		.private = offsetof(struct cfq_group, stats.empty_time),
-		.seq_show = cfqg_print_stat,
-	},
-	{
-		.name = "dequeue",
-		.private = offsetof(struct cfq_group, stats.dequeue),
-		.seq_show = cfqg_print_stat,
-	},
-	{
-		.name = "unaccounted_time",
-		.private = offsetof(struct cfq_group, stats.unaccounted_time),
-		.seq_show = cfqg_print_stat,
-	},
-#endif	/* CONFIG_DEBUG_BLK_CGROUP */
-	{ }	/* terminate */
-};
 
-static int cfq_print_weight_on_dfl(struct seq_file *sf, void *v)
+static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
+				      struct cfq_queue *cfqq)
 {
-	struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
-	struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
-
-	seq_printf(sf, "default %u\n", cgd->weight);
-	blkcg_print_blkgs(sf, blkcg, cfqg_prfill_weight_device,
-			  &blkcg_policy_cfq, 0, false);
-	return 0;
+	/*
+	 * just an approximation, should be ok.
+	 */
+	return (cfqd->busy_queues - 1) * (cfq_prio_slice(cfqd, 1, 0) -
+		       cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio));
 }
 
-static ssize_t cfq_set_weight_on_dfl(struct kernfs_open_file *of,
-				     char *buf, size_t nbytes, loff_t off)
+static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq,
+						unsigned int *unaccounted_time)
 {
-	char *endp;
-	int ret;
-	u64 v;
-
-	buf = strim(buf);
+	unsigned int slice_used;
 
-	/* "WEIGHT" or "default WEIGHT" sets the default weight */
-	v = simple_strtoull(buf, &endp, 0);
-	if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) {
-		ret = __cfq_set_weight(of_css(of), v, true, false, false);
-		return ret ?: nbytes;
+	/*
+	 * Queue got expired before even a single request completed or
+	 * got expired immediately after first request completion.
+	 */
+	if (!cfqq->slice_start ||
+	    time_in_range(cfqq->slice_start, jiffies, jiffies))
+		slice_used = max_t(unsigned int,
+				   (jiffies - cfqq->dispatch_start), 1);
+	else {
+		slice_used = jiffies - cfqq->slice_start;
+		if (slice_used > cfqq->allocated_slice) {
+			*unaccounted_time = slice_used - cfqq->allocated_slice;
+			slice_used = cfqq->allocated_slice;
+		}
+		if (time_after(cfqq->slice_start, cfqq->dispatch_start))
+			*unaccounted_time += cfqq->slice_start -
+					cfqq->dispatch_start;
 	}
 
-	/* "MAJ:MIN WEIGHT" */
-	return __cfqg_set_weight_device(of, buf, nbytes, off, true, false);
-}
-
-static struct cftype cfq_blkcg_files[] = {
-	{
-		.name = "weight",
-		.flags = CFTYPE_NOT_ON_ROOT,
-		.seq_show = cfq_print_weight_on_dfl,
-		.write = cfq_set_weight_on_dfl,
-	},
-	{ }	/* terminate */
-};
-
-#else /* GROUP_IOSCHED */
-static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd,
-					 struct blkcg *blkcg)
-{
-	return cfqd->root_group;
-}
-
-static inline void
-cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) {
-	cfqq->cfqg = cfqg;
+	return slice_used;
 }
 
-#endif /* GROUP_IOSCHED */
-
 /*
  * The cfqd->service_trees holds all pending cfq_queue's that have
  * requests waiting to be processed. It is sorted in the order that
@@ -2204,7 +677,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 	int left;
 	int new_cfqq = 1;
 
-	st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq));
+	st = &cfqd->service_trees[cfqq_class(cfqq)][cfqq_type(cfqq)];
 	if (cfq_class_idle(cfqq)) {
 		rb_key = CFQ_IDLE_DELAY;
 		parent = rb_last(&st->rb);
@@ -2269,7 +742,6 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 	st->count++;
 	if (add_front || !new_cfqq)
 		return;
-	cfq_group_notify_queue_add(cfqd, cfqq->cfqg);
 }
 
 /*
@@ -2319,7 +791,6 @@ static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 		cfqq->p_root = NULL;
 	}
 
-	cfq_group_notify_queue_del(cfqd, cfqq->cfqg);
 	BUG_ON(!cfqd->busy_queues);
 	cfqd->busy_queues--;
 	if (cfq_cfqq_sync(cfqq))
@@ -2378,10 +849,7 @@ static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
 {
 	elv_rb_del(&cfqq->sort_list, rq);
 	cfqq->queued[rq_is_sync(rq)]--;
-	cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags);
 	cfq_add_rq_rb(rq);
-	cfqg_stats_update_io_add(RQ_CFQG(rq), cfqq->cfqd->serving_group,
-				 rq->cmd_flags);
 }
 
 static struct request *
@@ -2434,7 +902,6 @@ static void cfq_remove_request(struct request *rq)
 	cfq_del_rq_rb(rq);
 
 	cfqq->cfqd->rq_queued--;
-	cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags);
 	if (rq->cmd_flags & REQ_PRIO) {
 		WARN_ON(!cfqq->prio_pending);
 		cfqq->prio_pending--;
@@ -2466,12 +933,6 @@ static void cfq_merged_request(struct request_queue *q, struct request *req,
 	}
 }
 
-static void cfq_bio_merged(struct request_queue *q, struct request *req,
-				struct bio *bio)
-{
-	cfqg_stats_update_io_merged(RQ_CFQG(req), bio->bi_rw);
-}
-
 static void
 cfq_merged_requests(struct request_queue *q, struct request *rq,
 		    struct request *next)
@@ -2492,7 +953,6 @@ cfq_merged_requests(struct request_queue *q, struct request *rq,
 	if (cfqq->next_rq == next)
 		cfqq->next_rq = rq;
 	cfq_remove_request(next);
-	cfqg_stats_update_io_merged(RQ_CFQG(rq), next->cmd_flags);
 
 	cfqq = RQ_CFQQ(next);
 	/*
@@ -2533,7 +993,6 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq,
 static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
 	del_timer(&cfqd->idle_slice_timer);
-	cfqg_stats_update_idle_time(cfqq->cfqg);
 }
 
 static void __cfq_set_active_queue(struct cfq_data *cfqd,
@@ -2542,7 +1001,6 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd,
 	if (cfqq) {
 		cfq_log_cfqq(cfqd, cfqq, "set_active wl_class:%d wl_type:%d",
 				cfqd->serving_wl_class, cfqd->serving_wl_type);
-		cfqg_stats_update_avg_queue_size(cfqq->cfqg);
 		cfqq->slice_start = 0;
 		cfqq->dispatch_start = jiffies;
 		cfqq->allocated_slice = 0;
@@ -2588,8 +1046,6 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 		cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid);
 	}
 
-	cfq_group_served(cfqd, cfqq->cfqg, cfqq);
-
 	if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
 		cfq_del_cfqq_rr(cfqd, cfqq);
 
@@ -2618,8 +1074,9 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out)
  */
 static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
 {
-	struct cfq_rb_root *st = st_for(cfqd->serving_group,
-			cfqd->serving_wl_class, cfqd->serving_wl_type);
+	struct cfq_rb_root *st =
+		&cfqd->service_trees[cfqd->serving_wl_class]
+				    [cfqd->serving_wl_type];
 
 	if (!cfqd->rq_queued)
 		return NULL;
@@ -2634,7 +1091,6 @@ static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
 
 static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd)
 {
-	struct cfq_group *cfqg;
 	struct cfq_queue *cfqq;
 	int i, j;
 	struct cfq_rb_root *st;
@@ -2642,11 +1098,7 @@ static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd)
 	if (!cfqd->rq_queued)
 		return NULL;
 
-	cfqg = cfq_get_next_cfqg(cfqd);
-	if (!cfqg)
-		return NULL;
-
-	for_each_cfqg_st(cfqg, i, j, st)
+	for_each_st(cfqd, i, j, st)
 		if ((cfqq = cfq_rb_first(st)) != NULL)
 			return cfqq;
 	return NULL;
@@ -2702,7 +1154,7 @@ static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 	 * in their service tree.
 	 */
 	if (st->count == 1 && cfq_cfqq_sync(cfqq) &&
-	   !cfq_io_thinktime_big(cfqd, &st->ttime, false))
+	   !cfq_io_thinktime_big(cfqd, &st->ttime))
 		return true;
 	cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", st->count);
 	return false;
@@ -2711,25 +1163,13 @@ static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 static void cfq_arm_slice_timer(struct cfq_data *cfqd)
 {
 	struct cfq_queue *cfqq = cfqd->active_queue;
-	struct cfq_rb_root *st = cfqq->service_tree;
 	struct cfq_io_cq *cic;
-	unsigned long sl, group_idle = 0;
+	unsigned long sl;
 
 	WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list));
 	WARN_ON(cfq_cfqq_slice_new(cfqq));
 
 	/*
-	 * idle is disabled, either manually or by past process history
-	 */
-	if (!cfq_should_idle(cfqd, cfqq)) {
-		/* no queue idling. Check for group idling */
-		if (cfqd->cfq_group_idle)
-			group_idle = cfqd->cfq_group_idle;
-		else
-			return;
-	}
-
-	/*
 	 * still active requests from this queue, don't idle
 	 */
 	if (cfqq->dispatched)
@@ -2754,26 +1194,12 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
 		return;
 	}
 
-	/*
-	 * There are other queues in the group or this is the only group and
-	 * it has too big thinktime, don't do group idle.
-	 */
-	if (group_idle &&
-	    (cfqq->cfqg->nr_cfqq > 1 ||
-	     cfq_io_thinktime_big(cfqd, &st->ttime, true)))
-		return;
-
 	cfq_mark_cfqq_wait_request(cfqq);
 
-	if (group_idle)
-		sl = cfqd->cfq_group_idle;
-	else
-		sl = cfqd->cfq_slice_idle;
+	sl = cfqd->cfq_slice_idle;
 
 	mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
-	cfqg_stats_set_start_idle_time(cfqq->cfqg);
-	cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu group_idle: %d", sl,
-			group_idle ? 1 : 0);
+	cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl);
 }
 
 /*
@@ -2789,7 +1215,6 @@ static void cfq_dispatch_insert(struct request_queue *q, struct request *rq)
 	cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq);
 	cfq_remove_request(rq);
 	cfqq->dispatched++;
-	(RQ_CFQG(rq))->dispatched++;
 	elv_dispatch_sort(q, rq);
 
 	cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++;
@@ -2830,7 +1255,7 @@ cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 }
 
 static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd,
-			struct cfq_group *cfqg, enum wl_class_t wl_class)
+			enum wl_class_t wl_class)
 {
 	struct cfq_queue *queue;
 	int i;
@@ -2840,7 +1265,7 @@ static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd,
 
 	for (i = 0; i <= SYNC_WORKLOAD; ++i) {
 		/* select the one with lowest rb_key */
-		queue = cfq_rb_first(st_for(cfqg, wl_class, i));
+		queue = cfq_rb_first(&cfqd->service_trees[wl_class][i]);
 		if (queue &&
 		    (!key_valid || time_before(queue->rb_key, lowest_key))) {
 			lowest_key = queue->rb_key;
@@ -2853,18 +1278,17 @@ static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd,
 }
 
 static void
-choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg)
+choose_wl_class_and_type(struct cfq_data *cfqd)
 {
 	unsigned slice;
 	unsigned count;
 	struct cfq_rb_root *st;
-	unsigned group_slice;
 	enum wl_class_t original_class = cfqd->serving_wl_class;
 
 	/* Choose next priority. RT > BE > IDLE */
-	if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg))
+	if (cfq_busy_queues_wl(RT_WORKLOAD, cfqd))
 		cfqd->serving_wl_class = RT_WORKLOAD;
-	else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg))
+	else if (cfq_busy_queues_wl(BE_WORKLOAD, cfqd))
 		cfqd->serving_wl_class = BE_WORKLOAD;
 	else {
 		cfqd->serving_wl_class = IDLE_WORKLOAD;
@@ -2880,7 +1304,8 @@ choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg)
 	 * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload
 	 * expiration time
 	 */
-	st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type);
+	st = &cfqd->service_trees[cfqd->serving_wl_class]
+				 [cfqd->serving_wl_type];
 	count = st->count;
 
 	/*
@@ -2891,79 +1316,29 @@ choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg)
 
 new_workload:
 	/* otherwise select new workload type */
-	cfqd->serving_wl_type = cfq_choose_wl_type(cfqd, cfqg,
+	cfqd->serving_wl_type = cfq_choose_wl_type(cfqd,
 					cfqd->serving_wl_class);
-	st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type);
+	st = &cfqd->service_trees[cfqd->serving_wl_class]
+				 [cfqd->serving_wl_type];
 	count = st->count;
 
-	/*
-	 * the workload slice is computed as a fraction of target latency
-	 * proportional to the number of queues in that workload, over
-	 * all the queues in the same priority class
-	 */
-	group_slice = cfq_group_slice(cfqd, cfqg);
-
-	slice = group_slice * count /
-		max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_wl_class],
-		      cfq_group_busy_queues_wl(cfqd->serving_wl_class, cfqd,
-					cfqg));
-
 	if (cfqd->serving_wl_type == ASYNC_WORKLOAD) {
-		unsigned int tmp;
-
-		/*
-		 * Async queues are currently system wide. Just taking
-		 * proportion of queues with-in same group will lead to higher
-		 * async ratio system wide as generally root group is going
-		 * to have higher weight. A more accurate thing would be to
-		 * calculate system wide asnc/sync ratio.
-		 */
-		tmp = cfqd->cfq_target_latency *
-			cfqg_busy_async_queues(cfqd, cfqg);
-		tmp = tmp/cfqd->busy_queues;
-		slice = min_t(unsigned, slice, tmp);
+		slice = cfqd->cfq_target_latency *
+			cfq_busy_async_queues(cfqd);
+		slice = slice/cfqd->busy_queues;
 
 		/* async workload slice is scaled down according to
 		 * the sync/async slice ratio. */
 		slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1];
 	} else
-		/* sync workload slice is at least 2 * cfq_slice_idle */
-		slice = max(slice, 2 * cfqd->cfq_slice_idle);
+		/* sync workload slice is 2 * cfq_slice_idle */
+		slice = 2 * cfqd->cfq_slice_idle;
 
 	slice = max_t(unsigned, slice, CFQ_MIN_TT);
 	cfq_log(cfqd, "workload slice:%d", slice);
 	cfqd->workload_expires = jiffies + slice;
 }
 
-static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd)
-{
-	struct cfq_rb_root *st = &cfqd->grp_service_tree;
-	struct cfq_group *cfqg;
-
-	if (RB_EMPTY_ROOT(&st->rb))
-		return NULL;
-	cfqg = cfq_rb_first_group(st);
-	update_min_vdisktime(st);
-	return cfqg;
-}
-
-static void cfq_choose_cfqg(struct cfq_data *cfqd)
-{
-	struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd);
-
-	cfqd->serving_group = cfqg;
-
-	/* Restore the workload type data */
-	if (cfqg->saved_wl_slice) {
-		cfqd->workload_expires = jiffies + cfqg->saved_wl_slice;
-		cfqd->serving_wl_type = cfqg->saved_wl_type;
-		cfqd->serving_wl_class = cfqg->saved_wl_class;
-	} else
-		cfqd->workload_expires = jiffies - 1;
-
-	choose_wl_class_and_type(cfqd, cfqg);
-}
-
 /*
  * Select a queue for service. If we have a current active queue,
  * check whether to continue servicing it, or retrieve and set a new one.
@@ -2979,9 +1354,6 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
 	if (!cfqd->rq_queued)
 		return NULL;
 
-	/*
-	 * We were waiting for group to get backlogged. Expire the queue
-	 */
 	if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list))
 		goto expire;
 
@@ -2992,18 +1364,17 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
 		/*
 		 * If slice had not expired at the completion of last request
 		 * we might not have turned on wait_busy flag. Don't expire
-		 * the queue yet. Allow the group to get backlogged.
+		 * the queue yet. Allow the device to get backlogged.
 		 *
 		 * The very fact that we have used the slice, that means we
 		 * have been idling all along on this queue and it should be
 		 * ok to wait for this request to complete.
 		 */
-		if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list)
+		if (cfqd->busy_queues == 1 && RB_EMPTY_ROOT(&cfqq->sort_list)
 		    && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) {
 			cfqq = NULL;
 			goto keep_queue;
-		} else
-			goto check_group_idle;
+		}
 	}
 
 	/*
@@ -3037,18 +1408,6 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
 		goto keep_queue;
 	}
 
-	/*
-	 * If group idle is enabled and there are requests dispatched from
-	 * this group, wait for requests to complete.
-	 */
-check_group_idle:
-	if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1 &&
-	    cfqq->cfqg->dispatched &&
-	    !cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) {
-		cfqq = NULL;
-		goto keep_queue;
-	}
-
 expire:
 	cfq_slice_expired(cfqd, 0);
 new_queue:
@@ -3057,7 +1416,7 @@ new_queue:
 	 * service tree
 	 */
 	if (!new_cfqq)
-		cfq_choose_cfqg(cfqd);
+		choose_wl_class_and_type(cfqd);
 
 	cfqq = cfq_set_active_queue(cfqd, new_cfqq);
 keep_queue:
@@ -3282,13 +1641,11 @@ static int cfq_dispatch_requests(struct request_queue *q, int force)
  * task holds one reference to the queue, dropped when task exits. each rq
  * in-flight on this queue also holds a reference, dropped when rq is freed.
  *
- * Each cfq queue took a reference on the parent group. Drop it now.
- * queue lock must be held here.
+ * Queue lock must be held here.
  */
 static void cfq_put_queue(struct cfq_queue *cfqq)
 {
 	struct cfq_data *cfqd = cfqq->cfqd;
-	struct cfq_group *cfqg;
 
 	BUG_ON(cfqq->ref <= 0);
 
@@ -3299,7 +1656,6 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
 	cfq_log_cfqq(cfqd, cfqq, "put_queue");
 	BUG_ON(rb_first(&cfqq->sort_list));
 	BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]);
-	cfqg = cfqq->cfqg;
 
 	if (unlikely(cfqd->active_queue == cfqq)) {
 		__cfq_slice_expired(cfqd, cfqq, 0);
@@ -3308,7 +1664,6 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
 
 	BUG_ON(cfq_cfqq_on_rr(cfqq));
 	kmem_cache_free(cfq_pool, cfqq);
-	cfqg_put(cfqg);
 }
 
 static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
@@ -3433,61 +1788,19 @@ static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 	cfqq->pid = pid;
 }
 
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio)
-{
-	struct cfq_data *cfqd = cic_to_cfqd(cic);
-	struct cfq_queue *cfqq;
-	uint64_t serial_nr;
-
-	rcu_read_lock();
-	serial_nr = bio_blkcg(bio)->css.serial_nr;
-	rcu_read_unlock();
-
-	/*
-	 * Check whether blkcg has changed.  The condition may trigger
-	 * spuriously on a newly created cic but there's no harm.
-	 */
-	if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr))
-		return;
-
-	/*
-	 * Drop reference to queues.  New queues will be assigned in new
-	 * group upon arrival of fresh requests.
-	 */
-	cfqq = cic_to_cfqq(cic, false);
-	if (cfqq) {
-		cfq_log_cfqq(cfqd, cfqq, "changed cgroup");
-		cic_set_cfqq(cic, NULL, false);
-		cfq_put_queue(cfqq);
-	}
-
-	cfqq = cic_to_cfqq(cic, true);
-	if (cfqq) {
-		cfq_log_cfqq(cfqd, cfqq, "changed cgroup");
-		cic_set_cfqq(cic, NULL, true);
-		cfq_put_queue(cfqq);
-	}
-
-	cic->blkcg_serial_nr = serial_nr;
-}
-#else
-static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { }
-#endif  /* CONFIG_CFQ_GROUP_IOSCHED */
-
 static struct cfq_queue **
-cfq_async_queue_prio(struct cfq_group *cfqg, int ioprio_class, int ioprio)
+cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio)
 {
 	switch (ioprio_class) {
 	case IOPRIO_CLASS_RT:
-		return &cfqg->async_cfqq[0][ioprio];
+		return &cfqd->async_cfqq[0][ioprio];
 	case IOPRIO_CLASS_NONE:
 		ioprio = IOPRIO_NORM;
 		/* fall through */
 	case IOPRIO_CLASS_BE:
-		return &cfqg->async_cfqq[1][ioprio];
+		return &cfqd->async_cfqq[1][ioprio];
 	case IOPRIO_CLASS_IDLE:
-		return &cfqg->async_idle_cfqq;
+		return &cfqd->async_idle_cfqq;
 	default:
 		BUG();
 	}
@@ -3501,14 +1814,8 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
 	int ioprio = IOPRIO_PRIO_DATA(cic->ioprio);
 	struct cfq_queue **async_cfqq = NULL;
 	struct cfq_queue *cfqq;
-	struct cfq_group *cfqg;
 
 	rcu_read_lock();
-	cfqg = cfq_lookup_cfqg(cfqd, bio_blkcg(bio));
-	if (!cfqg) {
-		cfqq = &cfqd->oom_cfqq;
-		goto out;
-	}
 
 	if (!is_sync) {
 		if (!ioprio_valid(cic->ioprio)) {
@@ -3516,7 +1823,7 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
 			ioprio = task_nice_ioprio(tsk);
 			ioprio_class = task_nice_ioclass(tsk);
 		}
-		async_cfqq = cfq_async_queue_prio(cfqg, ioprio_class, ioprio);
+		async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio);
 		cfqq = *async_cfqq;
 		if (cfqq)
 			goto out;
@@ -3531,7 +1838,6 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
 
 	cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync);
 	cfq_init_prio_data(cfqq, cic);
-	cfq_link_cfqq_cfqg(cfqq, cfqg);
 	cfq_log_cfqq(cfqd, cfqq, "alloced");
 
 	if (async_cfqq) {
@@ -3565,9 +1871,6 @@ cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 		__cfq_update_io_thinktime(&cfqq->service_tree->ttime,
 			cfqd->cfq_slice_idle);
 	}
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-	__cfq_update_io_thinktime(&cfqq->cfqg->ttime, cfqd->cfq_group_idle);
-#endif
 }
 
 static void
@@ -3658,14 +1961,6 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
 	if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq))
 		return true;
 
-	/*
-	 * Treat ancestors of current cgroup the same way as current cgroup.
-	 * For anybody else we disallow preemption to guarantee service
-	 * fairness among cgroups.
-	 */
-	if (!cfqg_is_descendant(cfqq->cfqg, new_cfqq->cfqg))
-		return false;
-
 	if (cfq_slice_used(cfqq))
 		return true;
 
@@ -3705,19 +2000,10 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
  */
 static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
-	enum wl_type_t old_type = cfqq_type(cfqd->active_queue);
-
 	cfq_log_cfqq(cfqd, cfqq, "preempt");
 	cfq_slice_expired(cfqd, 1);
 
 	/*
-	 * workload type is changed, don't save slice, otherwise preempt
-	 * doesn't happen
-	 */
-	if (old_type != cfqq_type(cfqq))
-		cfqq->cfqg->saved_wl_slice = 0;
-
-	/*
 	 * Put the new queue at the front of the of the current list,
 	 * so we know that it will be selected next.
 	 */
@@ -3766,10 +2052,8 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 				cfq_del_timer(cfqd, cfqq);
 				cfq_clear_cfqq_wait_request(cfqq);
 				__blk_run_queue(cfqd->queue);
-			} else {
-				cfqg_stats_update_idle_time(cfqq->cfqg);
+			} else
 				cfq_mark_cfqq_must_dispatch(cfqq);
-			}
 		}
 	} else if (cfq_should_preempt(cfqd, cfqq, rq)) {
 		/*
@@ -3794,8 +2078,6 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq)
 	rq->fifo_time = jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)];
 	list_add_tail(&rq->queuelist, &cfqq->fifo);
 	cfq_add_rq_rb(rq);
-	cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group,
-				 rq->cmd_flags);
 	cfq_rq_enqueued(cfqd, cfqq, rq);
 }
 
@@ -3844,14 +2126,6 @@ static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 	if (!RB_EMPTY_ROOT(&cfqq->sort_list))
 		return false;
 
-	/* If there are other queues in the group, don't wait */
-	if (cfqq->cfqg->nr_cfqq > 1)
-		return false;
-
-	/* the only queue in the group, but think time is big */
-	if (cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true))
-		return false;
-
 	if (cfq_slice_used(cfqq))
 		return true;
 
@@ -3890,9 +2164,6 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
 	WARN_ON(!cfqq->dispatched);
 	cfqd->rq_in_driver--;
 	cfqq->dispatched--;
-	(RQ_CFQG(rq))->dispatched--;
-	cfqg_stats_update_completion(cfqq->cfqg, rq_start_time_ns(rq),
-				     rq_io_start_time_ns(rq), rq->cmd_flags);
 
 	cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
 
@@ -3904,18 +2175,14 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
 		if (cfq_cfqq_on_rr(cfqq))
 			st = cfqq->service_tree;
 		else
-			st = st_for(cfqq->cfqg, cfqq_class(cfqq),
-					cfqq_type(cfqq));
+			st = &cfqd->service_trees[cfqq_class(cfqq)]
+						 [cfqq_type(cfqq)];
 
 		st->ttime.last_end_request = now;
 		if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now))
 			cfqd->last_delayed_sync = now;
 	}
 
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-	cfqq->cfqg->ttime.last_end_request = now;
-#endif
-
 	/*
 	 * 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.
@@ -3934,8 +2201,6 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
 		 */
 		if (cfq_should_wait_busy(cfqd, cfqq)) {
 			unsigned long extend_sl = cfqd->cfq_slice_idle;
-			if (!cfqd->cfq_slice_idle)
-				extend_sl = cfqd->cfq_group_idle;
 			cfqq->slice_end = jiffies + extend_sl;
 			cfq_mark_cfqq_wait_busy(cfqq);
 			cfq_log_cfqq(cfqd, cfqq, "will busy wait");
@@ -4008,8 +2273,6 @@ static void cfq_put_request(struct request *rq)
 		BUG_ON(!cfqq->allocated[rw]);
 		cfqq->allocated[rw]--;
 
-		/* Put down rq reference on cfqg */
-		cfqg_put(RQ_CFQG(rq));
 		rq->elv.priv[0] = NULL;
 		rq->elv.priv[1] = NULL;
 
@@ -4033,7 +2296,6 @@ cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio,
 	spin_lock_irq(q->queue_lock);
 
 	check_ioprio_changed(cic, bio);
-	check_blkcg_changed(cic, bio);
 
 	cfqq = cic_to_cfqq(cic, is_sync);
 	if (!cfqq || cfqq == &cfqd->oom_cfqq) {
@@ -4046,9 +2308,7 @@ cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio,
 	cfqq->allocated[rw]++;
 
 	cfqq->ref++;
-	cfqg_get(cfqq->cfqg);
 	rq->elv.priv[0] = cfqq;
-	rq->elv.priv[1] = cfqq->cfqg;
 	spin_unlock_irq(q->queue_lock);
 	return 0;
 }
@@ -4137,19 +2397,12 @@ static void cfq_exit_queue(struct elevator_queue *e)
 
 	cfq_shutdown_timer_wq(cfqd);
 
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-	blkcg_deactivate_policy(q, &blkcg_policy_cfq);
-#else
-	kfree(cfqd->root_group);
-#endif
 	kfree(cfqd);
 }
 
 static int cfq_init_queue(struct request_queue *q, struct elevator_type *e)
 {
 	struct cfq_data *cfqd;
-	struct blkcg_gq *blkg __maybe_unused;
-	int ret;
 	struct elevator_queue *eq;
 
 	eq = elevator_alloc(q, e);
@@ -4168,41 +2421,15 @@ static int cfq_init_queue(struct request_queue *q, struct elevator_type *e)
 	q->elevator = eq;
 	spin_unlock_irq(q->queue_lock);
 
-	/* Init root service tree */
-	cfqd->grp_service_tree = CFQ_RB_ROOT;
-
-	/* Init root group and prefer root group over other groups by default */
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-	ret = blkcg_activate_policy(q, &blkcg_policy_cfq);
-	if (ret)
-		goto out_free;
-
-	cfqd->root_group = blkg_to_cfqg(q->root_blkg);
-#else
-	ret = -ENOMEM;
-	cfqd->root_group = kzalloc_node(sizeof(*cfqd->root_group),
-					GFP_KERNEL, cfqd->queue->node);
-	if (!cfqd->root_group)
-		goto out_free;
-
-	cfq_init_cfqg_base(cfqd->root_group);
-	cfqd->root_group->weight = 2 * CFQ_WEIGHT_LEGACY_DFL;
-	cfqd->root_group->leaf_weight = 2 * CFQ_WEIGHT_LEGACY_DFL;
-#endif
-
 	/*
 	 * Our fallback cfqq if cfq_get_queue() runs into OOM issues.
 	 * Grab a permanent reference to it, so that the normal code flow
-	 * will not attempt to free it.  oom_cfqq is linked to root_group
-	 * but shouldn't hold a reference as it'll never be unlinked.  Lose
-	 * the reference from linking right away.
+	 * will not attempt to free it.
 	 */
 	cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0);
 	cfqd->oom_cfqq.ref++;
 
 	spin_lock_irq(q->queue_lock);
-	cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, cfqd->root_group);
-	cfqg_put(cfqd->root_group);
 	spin_unlock_irq(q->queue_lock);
 
 	init_timer(&cfqd->idle_slice_timer);
@@ -4221,7 +2448,6 @@ static int cfq_init_queue(struct request_queue *q, struct elevator_type *e)
 	cfqd->cfq_target_latency = cfq_target_latency;
 	cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
 	cfqd->cfq_slice_idle = cfq_slice_idle;
-	cfqd->cfq_group_idle = cfq_group_idle;
 	cfqd->cfq_latency = 1;
 	cfqd->hw_tag = -1;
 	/*
@@ -4230,11 +2456,6 @@ static int cfq_init_queue(struct request_queue *q, struct elevator_type *e)
 	 */
 	cfqd->last_delayed_sync = jiffies - HZ;
 	return 0;
-
-out_free:
-	kfree(cfqd);
-	kobject_put(&eq->kobj);
-	return ret;
 }
 
 static void cfq_registered_queue(struct request_queue *q)
@@ -4282,7 +2503,6 @@ SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1);
 SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0);
 SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0);
 SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1);
-SHOW_FUNCTION(cfq_group_idle_show, cfqd->cfq_group_idle, 1);
 SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1);
 SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1);
 SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0);
@@ -4315,7 +2535,6 @@ STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0);
 STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1,
 		UINT_MAX, 0);
 STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1);
-STORE_FUNCTION(cfq_group_idle_store, &cfqd->cfq_group_idle, 0, UINT_MAX, 1);
 STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1);
 STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1);
 STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1,
@@ -4337,7 +2556,6 @@ static struct elv_fs_entry cfq_attrs[] = {
 	CFQ_ATTR(slice_async),
 	CFQ_ATTR(slice_async_rq),
 	CFQ_ATTR(slice_idle),
-	CFQ_ATTR(group_idle),
 	CFQ_ATTR(low_latency),
 	CFQ_ATTR(target_latency),
 	__ATTR_NULL
@@ -4349,7 +2567,6 @@ static struct elevator_type iosched_cfq = {
 		.elevator_merged_fn =		cfq_merged_request,
 		.elevator_merge_req_fn =	cfq_merged_requests,
 		.elevator_allow_merge_fn =	cfq_allow_merge,
-		.elevator_bio_merged_fn =	cfq_bio_merged,
 		.elevator_dispatch_fn =		cfq_dispatch_requests,
 		.elevator_add_req_fn =		cfq_insert_request,
 		.elevator_activate_req_fn =	cfq_activate_request,
@@ -4373,24 +2590,6 @@ static struct elevator_type iosched_cfq = {
 	.elevator_owner =	THIS_MODULE,
 };
 
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-static struct blkcg_policy blkcg_policy_cfq = {
-	.dfl_cftypes		= cfq_blkcg_files,
-	.legacy_cftypes		= cfq_blkcg_legacy_files,
-
-	.cpd_alloc_fn		= cfq_cpd_alloc,
-	.cpd_init_fn		= cfq_cpd_init,
-	.cpd_free_fn		= cfq_cpd_free,
-	.cpd_bind_fn		= cfq_cpd_bind,
-
-	.pd_alloc_fn		= cfq_pd_alloc,
-	.pd_init_fn		= cfq_pd_init,
-	.pd_offline_fn		= cfq_pd_offline,
-	.pd_free_fn		= cfq_pd_free,
-	.pd_reset_stats_fn	= cfq_pd_reset_stats,
-};
-#endif
-
 static int __init cfq_init(void)
 {
 	int ret;
@@ -4403,21 +2602,10 @@ static int __init cfq_init(void)
 	if (!cfq_slice_idle)
 		cfq_slice_idle = 1;
 
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-	if (!cfq_group_idle)
-		cfq_group_idle = 1;
-
-	ret = blkcg_policy_register(&blkcg_policy_cfq);
-	if (ret)
-		return ret;
-#else
-	cfq_group_idle = 0;
-#endif
-
 	ret = -ENOMEM;
 	cfq_pool = KMEM_CACHE(cfq_queue, 0);
 	if (!cfq_pool)
-		goto err_pol_unreg;
+		return ret;
 
 	ret = elv_register(&iosched_cfq);
 	if (ret)
@@ -4427,18 +2615,11 @@ static int __init cfq_init(void)
 
 err_free_pool:
 	kmem_cache_destroy(cfq_pool);
-err_pol_unreg:
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-	blkcg_policy_unregister(&blkcg_policy_cfq);
-#endif
 	return ret;
 }
 
 static void __exit cfq_exit(void)
 {
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-	blkcg_policy_unregister(&blkcg_policy_cfq);
-#endif
 	elv_unregister(&iosched_cfq);
 	kmem_cache_destroy(cfq_pool);
 }
