blk-throttle: clean up blkg_policy_data alloc/init/exit/free methods

With the recent addition of alloc and free methods, things became
messier.  This patch reorganizes them according to the followings.

* ->pd_alloc_fn()

  Responsible for allocation and static initializations - the ones
  which can be done independent of where the pd might be attached.

* ->pd_init_fn()

  Initializations which require the knowledge of where the pd is
  attached.

* ->pd_free_fn()

  The counter part of pd_alloc_fn().  Static de-init and freeing.

This leaves ->pd_exit_fn() without any users.  Removed.

While at it, collapse an one liner function throtl_pd_exit(), which
has only one user, into its user.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Tejun Heo 2015-08-18 14:55:13 -07:00 committed by Jens Axboe
parent 4fb72036fb
commit b2ce2643cc
4 changed files with 31 additions and 54 deletions

View File

@ -402,15 +402,6 @@ static void blkg_destroy_all(struct request_queue *q)
void __blkg_release_rcu(struct rcu_head *rcu_head)
{
struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head);
int i;
/* tell policies that this one is being freed */
for (i = 0; i < BLKCG_MAX_POLS; i++) {
struct blkcg_policy *pol = blkcg_policy[i];
if (blkg->pd[i] && pol->pd_exit_fn)
pol->pd_exit_fn(blkg);
}
/* release the blkcg and parent blkg refs this blkg has been holding */
css_put(&blkg->blkcg->css);
@ -1127,8 +1118,6 @@ void blkcg_deactivate_policy(struct request_queue *q,
if (pol->pd_offline_fn)
pol->pd_offline_fn(blkg);
if (pol->pd_exit_fn)
pol->pd_exit_fn(blkg);
if (blkg->pd[pol->plid]) {
pol->pd_free_fn(blkg->pd[pol->plid]);

View File

@ -330,26 +330,19 @@ static struct bio *throtl_pop_queued(struct list_head *queued,
}
/* init a service_queue, assumes the caller zeroed it */
static void throtl_service_queue_init(struct throtl_service_queue *sq,
struct throtl_service_queue *parent_sq)
static void throtl_service_queue_init(struct throtl_service_queue *sq)
{
INIT_LIST_HEAD(&sq->queued[0]);
INIT_LIST_HEAD(&sq->queued[1]);
sq->pending_tree = RB_ROOT;
sq->parent_sq = parent_sq;
setup_timer(&sq->pending_timer, throtl_pending_timer_fn,
(unsigned long)sq);
}
static void throtl_service_queue_exit(struct throtl_service_queue *sq)
{
del_timer_sync(&sq->pending_timer);
}
static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node)
{
struct throtl_grp *tg;
int cpu;
int rw, cpu;
tg = kzalloc_node(sizeof(*tg), gfp, node);
if (!tg)
@ -361,6 +354,19 @@ static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node)
return NULL;
}
throtl_service_queue_init(&tg->service_queue);
for (rw = READ; rw <= WRITE; rw++) {
throtl_qnode_init(&tg->qnode_on_self[rw], tg);
throtl_qnode_init(&tg->qnode_on_parent[rw], tg);
}
RB_CLEAR_NODE(&tg->rb_node);
tg->bps[READ] = -1;
tg->bps[WRITE] = -1;
tg->iops[READ] = -1;
tg->iops[WRITE] = -1;
for_each_possible_cpu(cpu) {
struct tg_stats_cpu *stats_cpu = per_cpu_ptr(tg->stats_cpu, cpu);
@ -375,8 +381,7 @@ static void throtl_pd_init(struct blkcg_gq *blkg)
{
struct throtl_grp *tg = blkg_to_tg(blkg);
struct throtl_data *td = blkg->q->td;
struct throtl_service_queue *parent_sq;
int rw;
struct throtl_service_queue *sq = &tg->service_queue;
/*
* If on the default hierarchy, we switch to properly hierarchical
@ -391,25 +396,10 @@ static void throtl_pd_init(struct blkcg_gq *blkg)
* Limits of a group don't interact with limits of other groups
* regardless of the position of the group in the hierarchy.
*/
parent_sq = &td->service_queue;
sq->parent_sq = &td->service_queue;
if (cgroup_on_dfl(blkg->blkcg->css.cgroup) && blkg->parent)
parent_sq = &blkg_to_tg(blkg->parent)->service_queue;
throtl_service_queue_init(&tg->service_queue, parent_sq);
for (rw = READ; rw <= WRITE; rw++) {
throtl_qnode_init(&tg->qnode_on_self[rw], tg);
throtl_qnode_init(&tg->qnode_on_parent[rw], tg);
}
RB_CLEAR_NODE(&tg->rb_node);
sq->parent_sq = &blkg_to_tg(blkg->parent)->service_queue;
tg->td = td;
tg->bps[READ] = -1;
tg->bps[WRITE] = -1;
tg->iops[READ] = -1;
tg->iops[WRITE] = -1;
}
/*
@ -436,17 +426,11 @@ static void throtl_pd_online(struct blkcg_gq *blkg)
tg_update_has_rules(blkg_to_tg(blkg));
}
static void throtl_pd_exit(struct blkcg_gq *blkg)
{
struct throtl_grp *tg = blkg_to_tg(blkg);
throtl_service_queue_exit(&tg->service_queue);
}
static void throtl_pd_free(struct blkg_policy_data *pd)
{
struct throtl_grp *tg = pd_to_tg(pd);
del_timer_sync(&tg->service_queue.pending_timer);
free_percpu(tg->stats_cpu);
kfree(tg);
}
@ -1421,7 +1405,6 @@ static struct blkcg_policy blkcg_policy_throtl = {
.pd_alloc_fn = throtl_pd_alloc,
.pd_init_fn = throtl_pd_init,
.pd_online_fn = throtl_pd_online,
.pd_exit_fn = throtl_pd_exit,
.pd_free_fn = throtl_pd_free,
.pd_reset_stats_fn = throtl_pd_reset_stats,
};
@ -1616,7 +1599,7 @@ int blk_throtl_init(struct request_queue *q)
return -ENOMEM;
INIT_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn);
throtl_service_queue_init(&td->service_queue, NULL);
throtl_service_queue_init(&td->service_queue);
q->td = td;
td->queue = q;

View File

@ -1584,7 +1584,17 @@ static void cfq_cpd_init(const struct blkcg *blkcg)
static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)
{
return kzalloc_node(sizeof(struct cfq_group), gfp, node);
struct cfq_group *cfqg;
cfqg = kzalloc_node(sizeof(*cfqg), gfp, node);
if (!cfqg)
return NULL;
cfq_init_cfqg_base(cfqg);
cfqg_stats_init(&cfqg->stats);
cfqg_stats_init(&cfqg->dead_stats);
return &cfqg->pd;
}
static void cfq_pd_init(struct blkcg_gq *blkg)
@ -1592,11 +1602,8 @@ static void cfq_pd_init(struct blkcg_gq *blkg)
struct cfq_group *cfqg = blkg_to_cfqg(blkg);
struct cfq_group_data *cgd = blkcg_to_cfqgd(blkg->blkcg);
cfq_init_cfqg_base(cfqg);
cfqg->weight = cgd->weight;
cfqg->leaf_weight = cgd->leaf_weight;
cfqg_stats_init(&cfqg->stats);
cfqg_stats_init(&cfqg->dead_stats);
}
static void cfq_pd_offline(struct blkcg_gq *blkg)

View File

@ -128,7 +128,6 @@ typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node);
typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_exit_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg);
@ -145,7 +144,6 @@ struct blkcg_policy {
blkcg_pol_init_pd_fn *pd_init_fn;
blkcg_pol_online_pd_fn *pd_online_fn;
blkcg_pol_offline_pd_fn *pd_offline_fn;
blkcg_pol_exit_pd_fn *pd_exit_fn;
blkcg_pol_free_pd_fn *pd_free_fn;
blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn;
};