path: root/0005-BFQ-update-to-v8r8.patch

From 23a3965c19616da0b723f0a83288dfc76aace016 Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Sat, 4 Feb 2017 17:31:41 +0100
Subject: [PATCH 01/10] Remove wrong compilation warning

BUGFIX: Removed a wrong compilation warning, due to the compiler
not taking into account short circuit in a condition.

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-sched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/bfq-sched.c b/block/bfq-sched.c
index 797bce7..2e9dc59 100644
--- a/block/bfq-sched.c
+++ b/block/bfq-sched.c
@@ -1301,7 +1301,7 @@ static void bfq_deactivate_entity(struct bfq_entity *entity,
 				  bool expiration)
 {
 	struct bfq_sched_data *sd;
-	struct bfq_entity *parent;
+	struct bfq_entity *parent = NULL;
 
 	for_each_entity_safe(entity, parent) {
 		sd = entity->sched_data;

From 62fcb1a9aaa77eb835640d8681fd2f5ad0f1111a Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Mon, 19 Dec 2016 17:14:58 +0100
Subject: [PATCH 02/10] Add a ton of forgotten static qualifiers

BUGIFX: Added several forgotten static qualifiers in function
definitions (completely harmless issue).

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 2a2c130..98a1acd 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -107,7 +107,7 @@ static const int bfq_async_charge_factor = 10;
 /* Default timeout values, in jiffies, approximating CFQ defaults. */
 static const int bfq_timeout = (HZ / 8);
 
-struct kmem_cache *bfq_pool;
+static struct kmem_cache *bfq_pool;
 
 /* Below this threshold (in ns), we consider thinktime immediate. */
 #define BFQ_MIN_TT		(2 * NSEC_PER_MSEC)
@@ -1868,7 +1868,7 @@ static bool bfq_may_be_close_cooperator(struct bfq_queue *bfqq,
  * positives. In case bfqq is weight-raised, such false positives
  * would evidently degrade latency guarantees for bfqq.
  */
-bool wr_from_too_long(struct bfq_queue *bfqq)
+static bool wr_from_too_long(struct bfq_queue *bfqq)
 {
 	return bfqq->wr_coeff > 1 &&
 		time_is_before_jiffies(bfqq->last_wr_start_finish +
@@ -2298,7 +2298,7 @@ static unsigned long bfq_calc_max_budget(struct bfq_data *bfqd)
  * function of the estimated peak rate. See comments on
  * bfq_calc_max_budget(), and on T_slow and T_fast arrays.
  */
-void update_thr_responsiveness_params(struct bfq_data *bfqd)
+static void update_thr_responsiveness_params(struct bfq_data *bfqd)
 {
 	int dev_type = blk_queue_nonrot(bfqd->queue);
 
@@ -2333,7 +2333,7 @@ void update_thr_responsiveness_params(struct bfq_data *bfqd)
 		BFQ_RATE_SHIFT);
 }
 
-void bfq_reset_rate_computation(struct bfq_data *bfqd, struct request *rq)
+static void bfq_reset_rate_computation(struct bfq_data *bfqd, struct request *rq)
 {
 	if (rq != NULL) { /* new rq dispatch now, reset accordingly */
 		bfqd->last_dispatch = bfqd->first_dispatch = ktime_get_ns() ;
@@ -2350,7 +2350,7 @@ void bfq_reset_rate_computation(struct bfq_data *bfqd, struct request *rq)
 		bfqd->tot_sectors_dispatched);
 }
 
-void bfq_update_rate_reset(struct bfq_data *bfqd, struct request *rq)
+static void bfq_update_rate_reset(struct bfq_data *bfqd, struct request *rq)
 {
 	u32 rate, weight, divisor;
 
@@ -2515,7 +2515,7 @@ void bfq_update_rate_reset(struct bfq_data *bfqd, struct request *rq)
  * of the observed dispatch rate. The function assumes to be invoked
  * on every request dispatch.
  */
-void bfq_update_peak_rate(struct bfq_data *bfqd, struct request *rq)
+static void bfq_update_peak_rate(struct bfq_data *bfqd, struct request *rq)
 {
 	u64 now_ns = ktime_get_ns();
 

From 588042943eab576d65c0ebf57ccf57b82211e7c2 Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Fri, 3 Feb 2017 11:53:01 +0100
Subject: [PATCH 03/10] BUGFIX: Put async queues on exit also without cgroups

BUGFIX: The putting of async queues on scheduler exit was missing in case
cgroups support was not active. This fix adds the missing operation.

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-cgroup.c  |  3 +++
 block/bfq-iosched.c | 11 ++++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index bbaecd0..a5f8dc1 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -1140,6 +1140,9 @@ static inline void bfqg_stats_update_idle_time(struct bfq_group *bfqg) { }
 static inline void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg) { }
 static inline void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg) { }
 
+static void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+			  struct bfq_group *bfqg) {}
+
 static void bfq_init_entity(struct bfq_entity *entity,
 			    struct bfq_group *bfqg)
 {
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 98a1acd..517f513 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -4093,7 +4093,13 @@ static struct bfq_queue *bfq_get_queue(struct bfq_data *bfqd,
 	 * prune it.
 	 */
 	if (async_bfqq) {
-		bfqq->ref++;
+		bfqq->ref++; /*
+			      * Extra group reference, w.r.t. sync
+			      * queue. This extra reference is removed
+			      * only if bfqq->bfqg disappears, to
+			      * guarantee that this queue is not freed
+			      * until its group goes away.
+			      */
 		bfq_log_bfqq(bfqd, bfqq, "get_queue, bfqq not in async: %p, %d",
 			     bfqq, bfqq->ref);
 		*async_bfqq = bfqq;
@@ -4697,7 +4703,6 @@ static void bfq_shutdown_timer_wq(struct bfq_data *bfqd)
 	cancel_work_sync(&bfqd->unplug_work);
 }
 
-#ifdef CONFIG_BFQ_GROUP_IOSCHED
 static void __bfq_put_async_bfqq(struct bfq_data *bfqd,
 					struct bfq_queue **bfqq_ptr)
 {
@@ -4730,7 +4735,6 @@ static void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg)
 
 	__bfq_put_async_bfqq(bfqd, &bfqg->async_idle_bfqq);
 }
-#endif
 
 static void bfq_exit_queue(struct elevator_queue *e)
 {
@@ -4755,6 +4759,7 @@ static void bfq_exit_queue(struct elevator_queue *e)
 #ifdef CONFIG_BFQ_GROUP_IOSCHED
 	blkcg_deactivate_policy(q, &blkcg_policy_bfq);
 #else
+	bfq_put_async_queues(bfqd, bfqd->root_group);
 	kfree(bfqd->root_group);
 #endif
 

From 737da1cfab00974c57bdc132f93056e5c5da2cbb Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Sat, 4 Feb 2017 17:54:35 +0100
Subject: [PATCH 04/10] Fix check of the percentage of sequential dispatches

BUGFIX: In the peak-rate estimator, there was a serious error in the
check that the percentage of sequential I/O-request dispatches was high
enough to trigger an update of the peak-rate estimate. This commit fixes
that check.

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 517f513..d603cf9 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -2400,7 +2400,7 @@ static void bfq_update_rate_reset(struct bfq_data *bfqd, struct request *rq)
 	 *   total, and rate is below the current estimated peak rate
 	 * - rate is unreasonably high (> 20M sectors/sec)
 	 */
-	if ((bfqd->peak_rate_samples > (3 * bfqd->sequential_samples)>>2 &&
+	if ((bfqd->sequential_samples < (3 * bfqd->peak_rate_samples)>>2 &&
 	     rate <= bfqd->peak_rate) ||
 		rate > 20<<BFQ_RATE_SHIFT) {
 		bfq_log(bfqd,

From 7a2380425fe4d433a75982295fae3079f6a7b6a3 Mon Sep 17 00:00:00 2001
From: Luca Miccio <lucmiccio@gmail.com>
Date: Sat, 4 Feb 2017 18:03:06 +0100
Subject: [PATCH 05/10] Better tune weight-raising for slow flash-based devices

IMPROVEMENT Luca Miccio has run a few responsiveness tests on recent
Android systems with average-speed storage devices. These tests have
shown that the following BFQ parameter was too low for these systems:
reference duration for slow storage devices of weight raising for
interactive applications. This commit raises that duration to a
value that is yelding optimal results in our tests.

Signed-off-by: Luca Miccio <lucmiccio@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index d603cf9..ba82d8f 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5260,7 +5260,7 @@ static int __init bfq_init(void)
 	 * be run for a long time.
 	 */
 	T_slow[0] = msecs_to_jiffies(3500); /* actually 4 sec */
-	T_slow[1] = msecs_to_jiffies(1000); /* actually 1.5 sec */
+	T_slow[1] = msecs_to_jiffies(6000); /* actually 6.5 sec */
 	T_fast[0] = msecs_to_jiffies(7000); /* actually 8 sec */
 	T_fast[1] = msecs_to_jiffies(2500); /* actually 3 sec */
 

From 905e1281d01d0abcb151530cc362ad173b9b2959 Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Sat, 4 Feb 2017 18:16:59 +0100
Subject: [PATCH 06/10] BFQ-v8r8-rc1

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 2 +-
 block/bfq.h         | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index ba82d8f..7ffc167 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5234,7 +5234,7 @@ static struct blkcg_policy blkcg_policy_bfq = {
 static int __init bfq_init(void)
 {
 	int ret;
-	char msg[60] = "BFQ I/O-scheduler: v8r7";
+	char msg[60] = "BFQ I/O-scheduler: v8r8-rc1";
 
 #ifdef CONFIG_BFQ_GROUP_IOSCHED
 	ret = blkcg_policy_register(&blkcg_policy_bfq);
diff --git a/block/bfq.h b/block/bfq.h
index bef8244..7b12f3c 100644
--- a/block/bfq.h
+++ b/block/bfq.h
@@ -1,5 +1,5 @@
 /*
- * BFQ v8r7 for 4.9.0: data structures and common functions prototypes.
+ * BFQ v8r8-rc1 for 4.10.0: data structures and common functions prototypes.
  *
  * Based on ideas and code from CFQ:
  * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>

From 3955e8c82ce05297fb9e2c5beecbd8df9312abb3 Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Sun, 5 Feb 2017 18:50:51 +0100
Subject: [PATCH 07/10] Avoid a second dispatch in case of budget exhaustion

IMPROVEMENT This commit anticipates the complete check of budget exhaustion,
for the in-service bfq_queue, to when the next bfq_queue to serve is selected
(during a dispatch operation). This enables a new bfq_queue to be immediately
selected for service in case the in-service bfq_queue has actually exhausted
its budget. As a consequence, a second dispatch invocation is not needed
any more, to have a new request dispatched.
To implement this improvement, this commit implements a further improvement
too: the field next_rq of a bfq_queue now always contains the actual next
request to dispatch (or NULL if the bfq_queue is empty).

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 122 +++++++++++++++++++++++++++-------------------------
 1 file changed, 63 insertions(+), 59 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 7ffc167..2796927 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -519,13 +519,45 @@ static void bfq_weights_tree_remove(struct bfq_data *bfqd,
 	entity->weight_counter = NULL;
 }
 
+/*
+ * Return expired entry, or NULL to just start from scratch in rbtree.
+ */
+static struct request *bfq_check_fifo(struct bfq_queue *bfqq,
+				      struct request *last)
+{
+	struct request *rq;
+
+	if (bfq_bfqq_fifo_expire(bfqq))
+		return NULL;
+
+	bfq_mark_bfqq_fifo_expire(bfqq);
+
+	rq = rq_entry_fifo(bfqq->fifo.next);
+
+	if (rq == last || ktime_get_ns() < rq->fifo_time)
+		return NULL;
+
+	bfq_log_bfqq(bfqq->bfqd, bfqq, "check_fifo: returned %p", rq);
+	BUG_ON(RB_EMPTY_NODE(&rq->rb_node));
+	return rq;
+}
+
 static struct request *bfq_find_next_rq(struct bfq_data *bfqd,
 					struct bfq_queue *bfqq,
 					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;
+	struct request *next, *prev = NULL;
+
+	BUG_ON(list_empty(&bfqq->fifo));
+
+	/* Follow expired path, else get first next available. */
+	next = bfq_check_fifo(bfqq, last);
+	if (next) {
+		BUG_ON(next == last);
+		return next;
+	}
 
 	BUG_ON(RB_EMPTY_NODE(&last->rb_node));
 
@@ -1523,11 +1555,12 @@ static void bfq_remove_request(struct request *rq)
 	elv_rb_del(&bfqq->sort_list, rq);
 
 	if (RB_EMPTY_ROOT(&bfqq->sort_list)) {
+		bfqq->next_rq = NULL;
+
 		BUG_ON(bfqq->entity.budget < 0);
 
 		if (bfq_bfqq_busy(bfqq) && bfqq != bfqd->in_service_queue) {
 			bfq_del_bfqq_busy(bfqd, bfqq, false);
-
 			/* bfqq emptied. In normal operation, when
 			 * bfqq is empty, bfqq->entity.service and
 			 * bfqq->entity.budget must contain,
@@ -2616,29 +2649,6 @@ static void bfq_dispatch_insert(struct request_queue *q, struct request *rq)
 	elv_dispatch_sort(q, rq);
 }
 
-/*
- * Return expired entry, or NULL to just start from scratch in rbtree.
- */
-static struct request *bfq_check_fifo(struct bfq_queue *bfqq)
-{
-	struct request *rq = NULL;
-
-	if (bfq_bfqq_fifo_expire(bfqq))
-		return NULL;
-
-	bfq_mark_bfqq_fifo_expire(bfqq);
-
-	if (list_empty(&bfqq->fifo))
-		return NULL;
-
-	rq = rq_entry_fifo(bfqq->fifo.next);
-
-	if (ktime_get_ns() < rq->fifo_time)
-		return NULL;
-
-	return rq;
-}
-
 static void __bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq)
 {
 	BUG_ON(bfqq != bfqd->in_service_queue);
@@ -3504,14 +3514,29 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
 	    !bfq_bfqq_must_idle(bfqq))
 		goto expire;
 
+check_queue:
+	/*
+	 * This loop is rarely executed more than once. Even when it
+	 * happens, it is much more convenient to re-execute this loop
+	 * than to return NULL and trigger a new dispatch to get a
+	 * request served.
+	 */
 	next_rq = bfqq->next_rq;
 	/*
 	 * If bfqq has requests queued and it has enough budget left to
 	 * serve them, keep the queue, otherwise expire it.
 	 */
 	if (next_rq) {
+		BUG_ON(RB_EMPTY_ROOT(&bfqq->sort_list));
+
 		if (bfq_serv_to_charge(next_rq, bfqq) >
 			bfq_bfqq_budget_left(bfqq)) {
+			/*
+			 * Expire the queue for budget exhaustion,
+			 * which makes sure that the next budget is
+			 * enough to serve the next request, even if
+			 * it comes from the fifo expired path.
+			 */
 			reason = BFQ_BFQQ_BUDGET_EXHAUSTED;
 			goto expire;
 		} else {
@@ -3559,9 +3584,16 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
 	bfq_bfqq_expire(bfqd, bfqq, false, reason);
 new_queue:
 	bfqq = bfq_set_in_service_queue(bfqd);
-	bfq_log(bfqd, "select_queue: new queue %d returned",
-		bfqq ? bfqq->pid : 0);
+	if (bfqq) {
+		bfq_log_bfqq(bfqd, bfqq, "select_queue: checking new queue");
+		goto check_queue;
+	}
 keep_queue:
+	if (bfqq)
+		bfq_log_bfqq(bfqd, bfqq, "select_queue: returned this queue");
+	else
+		bfq_log(bfqd, "select_queue: no queue returned");
+
 	return bfqq;
 }
 
@@ -3627,45 +3659,17 @@ static int bfq_dispatch_request(struct bfq_data *bfqd,
 				struct bfq_queue *bfqq)
 {
 	int dispatched = 0;
-	struct request *rq;
+	struct request *rq = bfqq->next_rq;
 	unsigned long service_to_charge;
 
 	BUG_ON(RB_EMPTY_ROOT(&bfqq->sort_list));
-
-	/* Follow expired path, else get first next available. */
-	rq = bfq_check_fifo(bfqq);
-	if (!rq)
-		rq = bfqq->next_rq;
+	BUG_ON(!rq);
 	service_to_charge = bfq_serv_to_charge(rq, bfqq);
 
-	if (service_to_charge > bfq_bfqq_budget_left(bfqq)) {
-		/*
-		 * This may happen if the next rq is chosen in fifo order
-		 * instead of sector order. The budget is properly
-		 * dimensioned to be always sufficient to serve the next
-		 * request only if it is chosen in sector order. The reason
-		 * is that it would be quite inefficient and little useful
-		 * to always make sure that the budget is large enough to
-		 * serve even the possible next rq in fifo order.
-		 * In fact, requests are seldom served in fifo order.
-		 *
-		 * Expire the queue for budget exhaustion, and make sure
-		 * that the next act_budget is enough to serve the next
-		 * request, even if it comes from the fifo expired path.
-		 */
-		bfqq->next_rq = rq;
-		/*
-		 * Since this dispatch is failed, make sure that
-		 * a new one will be performed
-		 */
-		if (!bfqd->rq_in_driver)
-			bfq_schedule_dispatch(bfqd);
-		BUG_ON(bfqq->entity.budget < bfqq->entity.service);
-		goto expire;
-	}
+	BUG_ON(service_to_charge > bfq_bfqq_budget_left(bfqq));
 
 	BUG_ON(bfqq->entity.budget < bfqq->entity.service);
-	/* Finally, insert request into driver dispatch list. */
+
 	bfq_bfqq_served(bfqq, service_to_charge);
 
 	BUG_ON(bfqq->entity.budget < bfqq->entity.service);

From 99a658b6797c828d52466c5ceef93cf9b3bd1268 Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Sun, 5 Feb 2017 22:56:25 +0100
Subject: [PATCH 08/10] BFQ-v8r8-rc2

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 4 ++--
 block/bfq.h         | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 2796927..5bfeb16 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -9,7 +9,7 @@
  *
  * Copyright (C) 2015 Paolo Valente <paolo.valente@unimore.it>
  *
- * Copyright (C) 2016 Paolo Valente <paolo.valente@linaro.org>
+ * Copyright (C) 2017 Paolo Valente <paolo.valente@linaro.org>
  *
  * Licensed under the GPL-2 as detailed in the accompanying COPYING.BFQ
  * file.
@@ -5238,7 +5238,7 @@ static struct blkcg_policy blkcg_policy_bfq = {
 static int __init bfq_init(void)
 {
 	int ret;
-	char msg[60] = "BFQ I/O-scheduler: v8r8-rc1";
+	char msg[60] = "BFQ I/O-scheduler: v8r8-rc2";
 
 #ifdef CONFIG_BFQ_GROUP_IOSCHED
 	ret = blkcg_policy_register(&blkcg_policy_bfq);
diff --git a/block/bfq.h b/block/bfq.h
index 7b12f3c..a08e8a6 100644
--- a/block/bfq.h
+++ b/block/bfq.h
@@ -1,5 +1,5 @@
 /*
- * BFQ v8r8-rc1 for 4.10.0: data structures and common functions prototypes.
+ * BFQ v8r8-rc2 for 4.10.0: data structures and common functions prototypes.
  *
  * Based on ideas and code from CFQ:
  * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
@@ -9,7 +9,7 @@
  *
  * Copyright (C) 2015 Paolo Valente <paolo.valente@unimore.it>
  *
- * Copyright (C) 2016 Paolo Valente <paolo.valente@linaro.org>
+ * Copyright (C) 2017 Paolo Valente <paolo.valente@linaro.org>
  */
 
 #ifndef _BFQ_H

From 0796dc37acb561ef9c544a68045ff9a016b1ccab Mon Sep 17 00:00:00 2001
From: Oleksandr Natalenko <oleksandr@natalenko.name>
Date: Mon, 20 Feb 2017 16:02:07 +0100
Subject: [PATCH 09/10] block/bfq-cgroup: fix bfq_bic_update_cgroup() API

bfq_bic_update_cgroup() should return nothing even if
CONFIG_BFQ_GROUP_IOSCHED is disabled.

Signed-off-by: Oleksandr Natalenko <oleksandr@natalenko.name>
---
 block/bfq-cgroup.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index a5f8dc1..de045cf 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -1157,13 +1157,7 @@ static void bfq_init_entity(struct bfq_entity *entity,
 	entity->sched_data = &bfqg->sched_data;
 }
 
-static struct bfq_group *
-bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio)
-{
-	struct bfq_data *bfqd = bic_to_bfqd(bic);
-
-	return bfqd->root_group;
-}
+static void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) {}
 
 static void bfq_end_wr_async(struct bfq_data *bfqd)
 {

From 99b8292bad900ffa16aea9cc9df7a68954026829 Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Thu, 23 Feb 2017 12:28:00 +0100
Subject: [PATCH 10/10] BFQ-v8r8

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 2 +-
 block/bfq.h         | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 5bfeb16..6348d55 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5238,7 +5238,7 @@ static struct blkcg_policy blkcg_policy_bfq = {
 static int __init bfq_init(void)
 {
 	int ret;
-	char msg[60] = "BFQ I/O-scheduler: v8r8-rc2";
+	char msg[60] = "BFQ I/O-scheduler: v8r8";
 
 #ifdef CONFIG_BFQ_GROUP_IOSCHED
 	ret = blkcg_policy_register(&blkcg_policy_bfq);
diff --git a/block/bfq.h b/block/bfq.h
index a08e8a6..2a2bc30 100644
--- a/block/bfq.h
+++ b/block/bfq.h
@@ -1,5 +1,5 @@
 /*
- * BFQ v8r8-rc2 for 4.10.0: data structures and common functions prototypes.
+ * BFQ v8r8 for 4.10.0: data structures and common functions prototypes.
  *
  * Based on ideas and code from CFQ:
  * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
0