/* Per cpu stats pointer */
struct tg_stats_cpu __percpu *stats_cpu;
-
- /* List of tgs waiting for per cpu stats memory to be allocated */
- struct list_head stats_alloc_node;
};
struct throtl_data
struct work_struct dispatch_work;
};
-/* list and work item to allocate percpu group stats */
-static DEFINE_SPINLOCK(tg_stats_alloc_lock);
-static LIST_HEAD(tg_stats_alloc_list);
-
-static void tg_stats_alloc_fn(struct work_struct *);
-static DECLARE_DELAYED_WORK(tg_stats_alloc_work, tg_stats_alloc_fn);
-
static void throtl_pending_timer_fn(unsigned long arg);
static inline struct throtl_grp *pd_to_tg(struct blkg_policy_data *pd)
} \
} while (0)
-static void tg_stats_init(struct tg_stats_cpu *tg_stats)
-{
- blkg_rwstat_init(&tg_stats->service_bytes);
- blkg_rwstat_init(&tg_stats->serviced);
-}
-
-/*
- * Worker for allocating per cpu stat for tgs. This is scheduled on the
- * system_wq once there are some groups on the alloc_list waiting for
- * allocation.
- */
-static void tg_stats_alloc_fn(struct work_struct *work)
-{
- static struct tg_stats_cpu *stats_cpu; /* this fn is non-reentrant */
- struct delayed_work *dwork = to_delayed_work(work);
- bool empty = false;
-
-alloc_stats:
- if (!stats_cpu) {
- int cpu;
-
- stats_cpu = alloc_percpu(struct tg_stats_cpu);
- if (!stats_cpu) {
- /* allocation failed, try again after some time */
- schedule_delayed_work(dwork, msecs_to_jiffies(10));
- return;
- }
- for_each_possible_cpu(cpu)
- tg_stats_init(per_cpu_ptr(stats_cpu, cpu));
- }
-
- spin_lock_irq(&tg_stats_alloc_lock);
-
- if (!list_empty(&tg_stats_alloc_list)) {
- struct throtl_grp *tg = list_first_entry(&tg_stats_alloc_list,
- struct throtl_grp,
- stats_alloc_node);
- swap(tg->stats_cpu, stats_cpu);
- list_del_init(&tg->stats_alloc_node);
- }
-
- empty = list_empty(&tg_stats_alloc_list);
- spin_unlock_irq(&tg_stats_alloc_lock);
- if (!empty)
- goto alloc_stats;
-}
-
static void throtl_qnode_init(struct throtl_qnode *qn, struct throtl_grp *tg)
{
INIT_LIST_HEAD(&qn->node);
}
/* 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)
+static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node)
{
- del_timer_sync(&sq->pending_timer);
+ struct throtl_grp *tg;
+ int rw, cpu;
+
+ tg = kzalloc_node(sizeof(*tg), gfp, node);
+ if (!tg)
+ return NULL;
+
+ tg->stats_cpu = alloc_percpu_gfp(struct tg_stats_cpu, gfp);
+ if (!tg->stats_cpu) {
+ kfree(tg);
+ 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);
+
+ blkg_rwstat_init(&stats_cpu->service_bytes);
+ blkg_rwstat_init(&stats_cpu->serviced);
+ }
+
+ return &tg->pd;
}
-static void throtl_pd_init(struct blkcg_gq *blkg)
+static void throtl_pd_init(struct blkg_policy_data *pd)
{
- struct throtl_grp *tg = blkg_to_tg(blkg);
+ struct throtl_grp *tg = pd_to_tg(pd);
+ struct blkcg_gq *blkg = tg_to_blkg(tg);
struct throtl_data *td = blkg->q->td;
- struct throtl_service_queue *parent_sq;
- unsigned long flags;
- int rw;
+ struct throtl_service_queue *sq = &tg->service_queue;
/*
* If on the default hierarchy, we switch to properly hierarchical
* 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;
-
- /*
- * Ugh... We need to perform per-cpu allocation for tg->stats_cpu
- * but percpu allocator can't be called from IO path. Queue tg on
- * tg_stats_alloc_list and allocate from work item.
- */
- spin_lock_irqsave(&tg_stats_alloc_lock, flags);
- list_add(&tg->stats_alloc_node, &tg_stats_alloc_list);
- schedule_delayed_work(&tg_stats_alloc_work, 0);
- spin_unlock_irqrestore(&tg_stats_alloc_lock, flags);
}
/*
(tg->bps[rw] != -1 || tg->iops[rw] != -1);
}
-static void throtl_pd_online(struct blkcg_gq *blkg)
+static void throtl_pd_online(struct blkg_policy_data *pd)
{
/*
* We don't want new groups to escape the limits of its ancestors.
* Update has_rules[] after a new group is brought online.
*/
- tg_update_has_rules(blkg_to_tg(blkg));
+ tg_update_has_rules(pd_to_tg(pd));
}
-static void throtl_pd_exit(struct blkcg_gq *blkg)
+static void throtl_pd_free(struct blkg_policy_data *pd)
{
- struct throtl_grp *tg = blkg_to_tg(blkg);
- unsigned long flags;
-
- spin_lock_irqsave(&tg_stats_alloc_lock, flags);
- list_del_init(&tg->stats_alloc_node);
- spin_unlock_irqrestore(&tg_stats_alloc_lock, flags);
+ struct throtl_grp *tg = pd_to_tg(pd);
+ del_timer_sync(&tg->service_queue.pending_timer);
free_percpu(tg->stats_cpu);
-
- throtl_service_queue_exit(&tg->service_queue);
+ kfree(tg);
}
-static void throtl_pd_reset_stats(struct blkcg_gq *blkg)
+static void throtl_pd_reset_stats(struct blkg_policy_data *pd)
{
- struct throtl_grp *tg = blkg_to_tg(blkg);
+ struct throtl_grp *tg = pd_to_tg(pd);
int cpu;
- if (tg->stats_cpu == NULL)
- return;
-
for_each_possible_cpu(cpu) {
struct tg_stats_cpu *sc = per_cpu_ptr(tg->stats_cpu, cpu);
static struct throtl_grp *throtl_lookup_tg(struct throtl_data *td,
struct blkcg *blkcg)
{
- /*
- * This is the common case when there are no blkcgs. Avoid lookup
- * in this case
- */
- if (blkcg == &blkcg_root)
- return td_root_tg(td);
-
return blkg_to_tg(blkg_lookup(blkcg, td->queue));
}
struct tg_stats_cpu *stats_cpu;
unsigned long flags;
- /* If per cpu stats are not allocated yet, don't do any accounting. */
- if (tg->stats_cpu == NULL)
- return;
-
/*
* Disabling interrupts to provide mutual exclusion between two
* writes on same cpu. It probably is not needed for 64bit. Not
struct blkg_rwstat rwstat = { }, tmp;
int i, cpu;
- if (tg->stats_cpu == NULL)
- return 0;
-
for_each_possible_cpu(cpu) {
struct tg_stats_cpu *sc = per_cpu_ptr(tg->stats_cpu, cpu);
}
static struct blkcg_policy blkcg_policy_throtl = {
- .pd_size = sizeof(struct throtl_grp),
.cftypes = throtl_files,
+ .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,
};
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;
projects / karo-tx-linux.git / blobdiff