Skip to content

Commit

Permalink
blk-throttle: clean up blkg_policy_data alloc/init/exit/free methods
Browse files Browse the repository at this point in the history 
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 <[email protected]>
Cc: Vivek Goyal <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
  • Loading branch information
@htejun @axboe
htejun authored and axboe committed Aug 18, 2015
1 parent 4fb7203 commit b2ce264
Show file tree
Hide file tree
Showing 4 changed files with 31 additions and 54 deletions.
11 changes: 0 additions & 11 deletions block/blk-cgroup.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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]);
Expand Down
57 changes: 20 additions & 37 deletions block/blk-throttle.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand All @@ -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);

Expand All @@ -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
Expand All @@ -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;
}

/*
Expand All @@ -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);
}
Expand Down Expand Up @@ -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,
};
Expand Down Expand Up @@ -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;
Expand Down
15 changes: 11 additions & 4 deletions block/cfq-iosched.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1584,19 +1584,26 @@ 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)
{
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)
Expand Down
2 changes: 0 additions & 2 deletions include/linux/blk-cgroup.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);

Expand All @@ -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;
};
Expand Down

0 comments on commit b2ce264

Please sign in to comment.