Commit f4da8072 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe

blkcg: remove blkcg->id

blkcg->id is a unique id given to each blkcg; however, the
cgroup_subsys_state which each blkcg embeds already has ->serial_nr
which can be used for the same purpose.  Drop blkcg->id and replace
its uses with blkcg->css.serial_nr.  Rename cfq_cgroup->blkcg_id to
->blkcg_serial_nr and @id in check_blkcg_changed() to @serial_nr for
consistency.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarVivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 55872c5a
...@@ -822,7 +822,6 @@ static void blkcg_css_free(struct cgroup_subsys_state *css) ...@@ -822,7 +822,6 @@ static void blkcg_css_free(struct cgroup_subsys_state *css)
static struct cgroup_subsys_state * static struct cgroup_subsys_state *
blkcg_css_alloc(struct cgroup_subsys_state *parent_css) blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
{ {
static atomic64_t id_seq = ATOMIC64_INIT(0);
struct blkcg *blkcg; struct blkcg *blkcg;
if (!parent_css) { if (!parent_css) {
...@@ -836,7 +835,6 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css) ...@@ -836,7 +835,6 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
blkcg->cfq_weight = CFQ_WEIGHT_DEFAULT; blkcg->cfq_weight = CFQ_WEIGHT_DEFAULT;
blkcg->cfq_leaf_weight = CFQ_WEIGHT_DEFAULT; blkcg->cfq_leaf_weight = CFQ_WEIGHT_DEFAULT;
blkcg->id = atomic64_inc_return(&id_seq); /* root is 0, start from 1 */
done: done:
spin_lock_init(&blkcg->lock); spin_lock_init(&blkcg->lock);
INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_ATOMIC); INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_ATOMIC);
......
...@@ -50,9 +50,6 @@ struct blkcg { ...@@ -50,9 +50,6 @@ struct blkcg {
struct blkcg_gq *blkg_hint; struct blkcg_gq *blkg_hint;
struct hlist_head blkg_list; struct hlist_head blkg_list;
/* for policies to test whether associated blkcg has changed */
uint64_t id;
/* TODO: per-policy storage in blkcg */ /* TODO: per-policy storage in blkcg */
unsigned int cfq_weight; /* belongs to cfq */ unsigned int cfq_weight; /* belongs to cfq */
unsigned int cfq_leaf_weight; unsigned int cfq_leaf_weight;
......
...@@ -299,7 +299,7 @@ struct cfq_io_cq { ...@@ -299,7 +299,7 @@ struct cfq_io_cq {
struct cfq_ttime ttime; struct cfq_ttime ttime;
int ioprio; /* the current ioprio */ int ioprio; /* the current ioprio */
#ifdef CONFIG_CFQ_GROUP_IOSCHED #ifdef CONFIG_CFQ_GROUP_IOSCHED
uint64_t blkcg_id; /* the current blkcg ID */ uint64_t blkcg_serial_nr; /* the current blkcg serial */
#endif #endif
}; };
...@@ -3534,17 +3534,17 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) ...@@ -3534,17 +3534,17 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio)
{ {
struct cfq_data *cfqd = cic_to_cfqd(cic); struct cfq_data *cfqd = cic_to_cfqd(cic);
struct cfq_queue *sync_cfqq; struct cfq_queue *sync_cfqq;
uint64_t id; uint64_t serial_nr;
rcu_read_lock(); rcu_read_lock();
id = bio_blkcg(bio)->id; serial_nr = bio_blkcg(bio)->css.serial_nr;
rcu_read_unlock(); rcu_read_unlock();
/* /*
* Check whether blkcg has changed. The condition may trigger * Check whether blkcg has changed. The condition may trigger
* spuriously on a newly created cic but there's no harm. * spuriously on a newly created cic but there's no harm.
*/ */
if (unlikely(!cfqd) || likely(cic->blkcg_id == id)) if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr))
return; return;
sync_cfqq = cic_to_cfqq(cic, 1); sync_cfqq = cic_to_cfqq(cic, 1);
...@@ -3558,7 +3558,7 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) ...@@ -3558,7 +3558,7 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio)
cfq_put_queue(sync_cfqq); cfq_put_queue(sync_cfqq);
} }
cic->blkcg_id = id; cic->blkcg_serial_nr = serial_nr;
} }
#else #else
static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { } static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { }
......
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