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From a1fd1c0e6e61f018ce4e9eb7d9ac917e13b39b09 Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Tue, 11 Apr 2017 12:28:10 +0200
Subject: [PATCH 1/4] BUGFIX: Handle failure of weight-counter allocation
Reported-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
block/bfq-iosched.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 090cbab..7d252f1 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -474,6 +474,22 @@ static void bfq_weights_tree_add(struct bfq_data *bfqd,
entity->weight_counter = kzalloc(sizeof(struct bfq_weight_counter),
GFP_ATOMIC);
+
+ /*
+ * In the unlucky event of an allocation failure, we just
+ * exit. This will cause the weight of entity to not be
+ * considered in bfq_differentiated_weights, which, in its
+ * turn, causes the scenario to be deemed wrongly symmetric in
+ * case entity's weight would have been the only weight making
+ * the scenario asymmetric. On the bright side, no unbalance
+ * will however occur when entity becomes inactive again (the
+ * invocation of this function is triggered by an activation
+ * of entity). In fact, bfq_weights_tree_remove does nothing
+ * if !entity->weight_counter.
+ */
+ if (unlikely(!entity->weight_counter))
+ return;
+
entity->weight_counter->weight = entity->weight;
rb_link_node(&entity->weight_counter->weights_node, parent, new);
rb_insert_color(&entity->weight_counter->weights_node, root);
From 7c64bf3c0712aa08441d196e55c67c525fb9fa0e Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Tue, 11 Apr 2017 12:32:03 +0200
Subject: [PATCH 2/4] BUGFIX: Remove problematic check on max service duration
Reported-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
block/bfq-iosched.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 7d252f1..1e3d9ba 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -2922,8 +2922,8 @@ static bool bfq_bfqq_is_slow(struct bfq_data *bfqd, struct bfq_queue *bfqq,
delta_ktime = ktime_sub(delta_ktime, bfqd->last_budget_start);
delta_usecs = ktime_to_us(delta_ktime);
- /* don't trust short/unrealistic values. */
- if (delta_usecs < 1000 || delta_usecs >= LONG_MAX) {
+ /* don't use too short time intervals */
+ if (delta_usecs < 1000) {
if (blk_queue_nonrot(bfqd->queue))
/*
* give same worst-case guarantees as idling
@@ -2933,7 +2933,7 @@ static bool bfq_bfqq_is_slow(struct bfq_data *bfqd, struct bfq_queue *bfqq,
else /* charge at least one seek */
*delta_ms = bfq_slice_idle / NSEC_PER_MSEC;
- bfq_log(bfqd, "bfq_bfqq_is_slow: unrealistic %u", delta_usecs);
+ bfq_log(bfqd, "bfq_bfqq_is_slow: too short %u", delta_usecs);
return slow;
}
From 3ae7c6e4bb147ba950b5caf2ced1739c709c60e6 Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Tue, 11 Apr 2017 12:35:09 +0200
Subject: [PATCH 3/4] BFQ-v8r10-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 1e3d9ba..540bd2d 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5257,7 +5257,7 @@ static struct blkcg_policy blkcg_policy_bfq = {
static int __init bfq_init(void)
{
int ret;
- char msg[60] = "BFQ I/O-scheduler: v8r9";
+ char msg[60] = "BFQ I/O-scheduler: v8r10-rc1";
#ifdef CONFIG_BFQ_GROUP_IOSCHED
ret = blkcg_policy_register(&blkcg_policy_bfq);
diff --git a/block/bfq.h b/block/bfq.h
index 4f7d0b8..0c73102 100644
--- a/block/bfq.h
+++ b/block/bfq.h
@@ -1,5 +1,5 @@
/*
- * BFQ v8r9 for 4.10.0: data structures and common functions prototypes.
+ * BFQ v8r10-rc1 for 4.11.0: data structures and common functions prototypes.
*
* Based on ideas and code from CFQ:
* Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
From 277f5737b68ef9bea5eede7882da621edfa2381c Mon Sep 17 00:00:00 2001
From: Paolo Valente <paolo.valente@linaro.org>
Date: Thu, 20 Apr 2017 09:46:53 +0200
Subject: [PATCH 4/4] BFQ-v8r10
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 540bd2d..59b1891 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5257,7 +5257,7 @@ static struct blkcg_policy blkcg_policy_bfq = {
static int __init bfq_init(void)
{
int ret;
- char msg[60] = "BFQ I/O-scheduler: v8r10-rc1";
+ char msg[60] = "BFQ I/O-scheduler: v8r10";
#ifdef CONFIG_BFQ_GROUP_IOSCHED
ret = blkcg_policy_register(&blkcg_policy_bfq);
diff --git a/block/bfq.h b/block/bfq.h
index 0c73102..7cb3240 100644
--- a/block/bfq.h
+++ b/block/bfq.h
@@ -1,5 +1,5 @@
/*
- * BFQ v8r10-rc1 for 4.11.0: data structures and common functions prototypes.
+ * BFQ v8r10 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>
|