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authorBruce Ashfield <bruce.ashfield@gmail.com>2019-07-22 11:15:13 -0400
committerBruce Ashfield <bruce.ashfield@gmail.com>2019-07-22 11:15:13 -0400
commitc7f55a28286aeebf0d03d7a95852aa788b1485f1 (patch)
treeb4a80cfd4193bd255c8949c668abb6aae1e15bcc /block/bfq-wf2q.c
parent113a670ce2eb3daca9fa9c4f43d064d002db7c9b (diff)
parente9b75c60f91a359cb0e1b2d0a9ed1c81485215e2 (diff)
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Merge branch 'master-5.2'
Diffstat (limited to 'block/bfq-wf2q.c')
-rw-r--r--block/bfq-wf2q.c60
1 files changed, 35 insertions, 25 deletions
diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
index 72adbbe975d5..c9ba225081ce 100644
--- a/block/bfq-wf2q.c
+++ b/block/bfq-wf2q.c
@@ -1,19 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Hierarchical Budget Worst-case Fair Weighted Fair Queueing
* (B-WF2Q+): hierarchical scheduling algorithm by which the BFQ I/O
* scheduler schedules generic entities. The latter can represent
* either single bfq queues (associated with processes) or groups of
* bfq queues (associated with cgroups).
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
*/
#include "bfq-iosched.h"
@@ -44,6 +35,12 @@ static unsigned int bfq_class_idx(struct bfq_entity *entity)
BFQ_DEFAULT_GRP_CLASS - 1;
}
+unsigned int bfq_tot_busy_queues(struct bfq_data *bfqd)
+{
+ return bfqd->busy_queues[0] + bfqd->busy_queues[1] +
+ bfqd->busy_queues[2];
+}
+
static struct bfq_entity *bfq_lookup_next_entity(struct bfq_sched_data *sd,
bool expiration);
@@ -53,7 +50,7 @@ static bool bfq_update_parent_budget(struct bfq_entity *next_in_service);
* bfq_update_next_in_service - update sd->next_in_service
* @sd: sched_data for which to perform the update.
* @new_entity: if not NULL, pointer to the entity whose activation,
- * requeueing or repositionig triggered the invocation of
+ * requeueing or repositioning triggered the invocation of
* this function.
* @expiration: id true, this function is being invoked after the
* expiration of the in-service entity
@@ -84,7 +81,7 @@ static bool bfq_update_next_in_service(struct bfq_sched_data *sd,
/*
* If this update is triggered by the activation, requeueing
- * or repositiong of an entity that does not coincide with
+ * or repositioning of an entity that does not coincide with
* sd->next_in_service, then a full lookup in the active tree
* can be avoided. In fact, it is enough to check whether the
* just-modified entity has the same priority as
@@ -731,7 +728,7 @@ __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st,
struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
unsigned int prev_weight, new_weight;
struct bfq_data *bfqd = NULL;
- struct rb_root *root;
+ struct rb_root_cached *root;
#ifdef CONFIG_BFQ_GROUP_IOSCHED
struct bfq_sched_data *sd;
struct bfq_group *bfqg;
@@ -1006,7 +1003,7 @@ static void __bfq_activate_entity(struct bfq_entity *entity,
entity->on_st = true;
}
-#ifdef BFQ_GROUP_IOSCHED_ENABLED
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
if (!bfq_entity_to_bfqq(entity)) { /* bfq_group */
struct bfq_group *bfqg =
container_of(entity, struct bfq_group, entity);
@@ -1390,7 +1387,7 @@ left:
* In this first case, update the virtual time in @st too (see the
* comments on this update inside the function).
*
- * In constrast, if there is an in-service entity, then return the
+ * In contrast, if there is an in-service entity, then return the
* entity that would be set in service if not only the above
* conditions, but also the next one held true: the currently
* in-service entity, on expiration,
@@ -1473,12 +1470,12 @@ static struct bfq_entity *bfq_lookup_next_entity(struct bfq_sched_data *sd,
* is being invoked as a part of the expiration path
* of the in-service queue. In this case, even if
* sd->in_service_entity is not NULL,
- * sd->in_service_entiy at this point is actually not
+ * sd->in_service_entity at this point is actually not
* in service any more, and, if needed, has already
* been properly queued or requeued into the right
* tree. The reason why sd->in_service_entity is still
* not NULL here, even if expiration is true, is that
- * sd->in_service_entiy is reset as a last step in the
+ * sd->in_service_entity is reset as a last step in the
* expiration path. So, if expiration is true, tell
* __bfq_lookup_next_entity that there is no
* sd->in_service_entity.
@@ -1513,7 +1510,7 @@ struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd)
struct bfq_sched_data *sd;
struct bfq_queue *bfqq;
- if (bfqd->busy_queues == 0)
+ if (bfq_tot_busy_queues(bfqd) == 0)
return NULL;
/*
@@ -1599,7 +1596,8 @@ struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd)
return bfqq;
}
-void __bfq_bfqd_reset_in_service(struct bfq_data *bfqd)
+/* returns true if the in-service queue gets freed */
+bool __bfq_bfqd_reset_in_service(struct bfq_data *bfqd)
{
struct bfq_queue *in_serv_bfqq = bfqd->in_service_queue;
struct bfq_entity *in_serv_entity = &in_serv_bfqq->entity;
@@ -1623,8 +1621,20 @@ void __bfq_bfqd_reset_in_service(struct bfq_data *bfqd)
* service tree either, then release the service reference to
* the queue it represents (taken with bfq_get_entity).
*/
- if (!in_serv_entity->on_st)
+ if (!in_serv_entity->on_st) {
+ /*
+ * If no process is referencing in_serv_bfqq any
+ * longer, then the service reference may be the only
+ * reference to the queue. If this is the case, then
+ * bfqq gets freed here.
+ */
+ int ref = in_serv_bfqq->ref;
bfq_put_queue(in_serv_bfqq);
+ if (ref == 1)
+ return true;
+ }
+
+ return false;
}
void bfq_deactivate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq,
@@ -1665,10 +1675,7 @@ void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq,
bfq_clear_bfqq_busy(bfqq);
- bfqd->busy_queues--;
-
- if (!bfqq->dispatched)
- bfq_weights_tree_remove(bfqd, bfqq);
+ bfqd->busy_queues[bfqq->ioprio_class - 1]--;
if (bfqq->wr_coeff > 1)
bfqd->wr_busy_queues--;
@@ -1676,6 +1683,9 @@ void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq,
bfqg_stats_update_dequeue(bfqq_group(bfqq));
bfq_deactivate_bfqq(bfqd, bfqq, true, expiration);
+
+ if (!bfqq->dispatched)
+ bfq_weights_tree_remove(bfqd, bfqq);
}
/*
@@ -1688,7 +1698,7 @@ void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq)
bfq_activate_bfqq(bfqd, bfqq);
bfq_mark_bfqq_busy(bfqq);
- bfqd->busy_queues++;
+ bfqd->busy_queues[bfqq->ioprio_class - 1]++;
if (!bfqq->dispatched)
if (bfqq->wr_coeff == 1)