blkcg: move per-queue blkg list heads and counters to queue and blkg

[mirror_ubuntu-artful-kernel.git] / block / cfq-iosched.c

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 11dd9d7f2edb3da6d5e3c0d0d6ecf847bcf6f32c..e846803280a6bb866a0dbc580e39afd2d5a19cd6 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -208,9 +208,7 @@ struct cfq_group {
        unsigned long saved_workload_slice;
        enum wl_type_t saved_workload;
        enum wl_prio_t saved_serving_prio;
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
-       struct hlist_node cfqd_node;
-#endif
+
        /* number of requests that are on the dispatch list or inside driver */
        int dispatched;
        struct cfq_ttime ttime;
@@ -302,12 +300,6 @@ struct cfq_data {
        struct cfq_queue oom_cfqq;
 
        unsigned long last_delayed_sync;
-
-       /* List of cfq groups being managed on this device*/
-       struct hlist_head cfqg_list;
-
-       /* Number of groups which are on blkcg->blkg_list */
-       unsigned int nr_blkcg_linked_grps;
 };
 
 static inline struct cfq_group *blkg_to_cfqg(struct blkio_group *blkg)
@@ -1056,13 +1048,9 @@ static void cfq_update_blkio_group_weight(struct request_queue *q,
 static void cfq_link_blkio_group(struct request_queue *q,
                                 struct blkio_group *blkg)
 {
-       struct cfq_data *cfqd = q->elevator->elevator_data;
-       struct cfq_group *cfqg = blkg_to_cfqg(blkg);
-
-       cfqd->nr_blkcg_linked_grps++;
-
-       /* Add group on cfqd list */
-       hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
+       list_add(&blkg->q_node[BLKIO_POLICY_PROP],
+                &q->blkg_list[BLKIO_POLICY_PROP]);
+       q->nr_blkgs[BLKIO_POLICY_PROP]++;
 }
 
 static void cfq_init_blkio_group(struct blkio_group *blkg)
@@ -1110,13 +1098,15 @@ static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg)
 
 static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg)
 {
+       struct blkio_group *blkg = cfqg_to_blkg(cfqg);
+
        /* Something wrong if we are trying to remove same group twice */
-       BUG_ON(hlist_unhashed(&cfqg->cfqd_node));
+       BUG_ON(list_empty(&blkg->q_node[BLKIO_POLICY_PROP]));
 
-       hlist_del_init(&cfqg->cfqd_node);
+       list_del_init(&blkg->q_node[BLKIO_POLICY_PROP]);
 
-       BUG_ON(cfqd->nr_blkcg_linked_grps <= 0);
-       cfqd->nr_blkcg_linked_grps--;
+       BUG_ON(cfqd->queue->nr_blkgs[BLKIO_POLICY_PROP] <= 0);
+       cfqd->queue->nr_blkgs[BLKIO_POLICY_PROP]--;
 
        /*
         * Put the reference taken at the time of creation so that when all
@@ -1127,18 +1117,19 @@ static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg)
 
 static bool cfq_release_cfq_groups(struct cfq_data *cfqd)
 {
-       struct hlist_node *pos, *n;
-       struct cfq_group *cfqg;
+       struct request_queue *q = cfqd->queue;
+       struct blkio_group *blkg, *n;
        bool empty = true;
 
-       hlist_for_each_entry_safe(cfqg, pos, n, &cfqd->cfqg_list, cfqd_node) {
+       list_for_each_entry_safe(blkg, n, &q->blkg_list[BLKIO_POLICY_PROP],
+                                q_node[BLKIO_POLICY_PROP]) {
                /*
                 * If cgroup removal path got to blk_group first and removed
                 * it from cgroup list, then it will take care of destroying
                 * cfqg also.
                 */
-               if (!cfq_blkiocg_del_blkio_group(cfqg_to_blkg(cfqg)))
-                       cfq_destroy_cfqg(cfqd, cfqg);
+               if (!cfq_blkiocg_del_blkio_group(blkg))
+                       cfq_destroy_cfqg(cfqd, blkg_to_cfqg(blkg));
                else
                        empty = false;
        }
@@ -3558,13 +3549,13 @@ static void cfq_exit_queue(struct elevator_queue *e)
        cfq_put_async_queues(cfqd);
        cfq_release_cfq_groups(cfqd);
 
+#ifdef CONFIG_BLK_CGROUP
        /*
         * If there are groups which we could not unlink from blkcg list,
         * wait for a rcu period for them to be freed.
         */
-       if (cfqd->nr_blkcg_linked_grps)
-               wait = true;
-
+       wait = q->nr_blkgs[BLKIO_POLICY_PROP];
+#endif
        spin_unlock_irq(q->queue_lock);
 
        cfq_shutdown_timer_wq(cfqd);