#define rb_entry_tg(node) rb_entry((node), struct throtl_grp, rb_node)
-/* Per-cpu group stats */
-struct tg_stats_cpu {
- /* total bytes transferred */
- struct blkg_rwstat service_bytes;
- /* total IOs serviced, post merge */
- struct blkg_rwstat serviced;
-};
-
struct throtl_grp {
/* must be the first member */
struct blkg_policy_data pd;
/* When did we start a new slice */
unsigned long slice_start[2];
unsigned long slice_end[2];
-
- /* 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)
return pd_to_blkg(&tg->pd);
}
-static inline struct throtl_grp *td_root_tg(struct throtl_data *td)
-{
- return blkg_to_tg(td->queue->root_blkg);
-}
-
/**
* sq_to_tg - return the throl_grp the specified service queue belongs to
* @sq: the throtl_service_queue of interest
} \
} 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;
+
+ tg = kzalloc_node(sizeof(*tg), gfp, node);
+ if (!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;
+
+ 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));
-}
-
-static void throtl_pd_exit(struct blkcg_gq *blkg)
-{
- 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);
-
- free_percpu(tg->stats_cpu);
-
- throtl_service_queue_exit(&tg->service_queue);
-}
-
-static void throtl_pd_reset_stats(struct blkcg_gq *blkg)
-{
- struct throtl_grp *tg = blkg_to_tg(blkg);
- 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);
-
- blkg_rwstat_reset(&sc->service_bytes);
- blkg_rwstat_reset(&sc->serviced);
- }
-}
-
-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));
+ tg_update_has_rules(pd_to_tg(pd));
}
-static struct throtl_grp *throtl_lookup_create_tg(struct throtl_data *td,
- struct blkcg *blkcg)
+static void throtl_pd_free(struct blkg_policy_data *pd)
{
- struct request_queue *q = td->queue;
- struct throtl_grp *tg = NULL;
-
- /*
- * This is the common case when there are no blkcgs. Avoid lookup
- * in this case
- */
- if (blkcg == &blkcg_root) {
- tg = td_root_tg(td);
- } else {
- struct blkcg_gq *blkg;
-
- blkg = blkg_lookup_create(blkcg, q);
-
- /* if %NULL and @q is alive, fall back to root_tg */
- if (!IS_ERR(blkg))
- tg = blkg_to_tg(blkg);
- else if (!blk_queue_dying(q))
- tg = td_root_tg(td);
- }
+ struct throtl_grp *tg = pd_to_tg(pd);
- return tg;
+ del_timer_sync(&tg->service_queue.pending_timer);
+ kfree(tg);
}
static struct throtl_grp *
return 0;
}
-static void throtl_update_dispatch_stats(struct blkcg_gq *blkg, u64 bytes,
- int rw)
-{
- struct throtl_grp *tg = blkg_to_tg(blkg);
- 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
- * optimizing that case yet.
- */
- local_irq_save(flags);
-
- stats_cpu = this_cpu_ptr(tg->stats_cpu);
-
- blkg_rwstat_add(&stats_cpu->serviced, rw, 1);
- blkg_rwstat_add(&stats_cpu->service_bytes, rw, bytes);
-
- local_irq_restore(flags);
-}
-
static void throtl_charge_bio(struct throtl_grp *tg, struct bio *bio)
{
bool rw = bio_data_dir(bio);
* more than once as a throttled bio will go through blk-throtl the
* second time when it eventually gets issued. Set it when a bio
* is being charged to a tg.
- *
- * Dispatch stats aren't recursive and each @bio should only be
- * accounted by the @tg it was originally associated with. Let's
- * update the stats when setting REQ_THROTTLED for the first time
- * which is guaranteed to be for the @bio's original tg.
*/
- if (!(bio->bi_rw & REQ_THROTTLED)) {
+ if (!(bio->bi_rw & REQ_THROTTLED))
bio->bi_rw |= REQ_THROTTLED;
- throtl_update_dispatch_stats(tg_to_blkg(tg),
- bio->bi_iter.bi_size, bio->bi_rw);
- }
}
/**
}
}
-static u64 tg_prfill_cpu_rwstat(struct seq_file *sf,
- struct blkg_policy_data *pd, int off)
-{
- struct throtl_grp *tg = pd_to_tg(pd);
- 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);
-
- tmp = blkg_rwstat_read((void *)sc + off);
- for (i = 0; i < BLKG_RWSTAT_NR; i++)
- rwstat.cnt[i] += tmp.cnt[i];
- }
-
- return __blkg_prfill_rwstat(sf, pd, &rwstat);
-}
-
-static int tg_print_cpu_rwstat(struct seq_file *sf, void *v)
-{
- blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_cpu_rwstat,
- &blkcg_policy_throtl, seq_cft(sf)->private, true);
- return 0;
-}
-
static u64 tg_prfill_conf_u64(struct seq_file *sf, struct blkg_policy_data *pd,
int off)
{
return 0;
}
-static ssize_t tg_set_conf(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off, bool is_u64)
+static void tg_conf_updated(struct throtl_grp *tg)
{
- struct blkcg *blkcg = css_to_blkcg(of_css(of));
- struct blkg_conf_ctx ctx;
- struct throtl_grp *tg;
- struct throtl_service_queue *sq;
- struct blkcg_gq *blkg;
+ struct throtl_service_queue *sq = &tg->service_queue;
struct cgroup_subsys_state *pos_css;
- int ret;
-
- ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx);
- if (ret)
- return ret;
-
- tg = blkg_to_tg(ctx.blkg);
- sq = &tg->service_queue;
-
- if (!ctx.v)
- ctx.v = -1;
-
- if (is_u64)
- *(u64 *)((void *)tg + of_cft(of)->private) = ctx.v;
- else
- *(unsigned int *)((void *)tg + of_cft(of)->private) = ctx.v;
+ struct blkcg_gq *blkg;
throtl_log(&tg->service_queue,
"limit change rbps=%llu wbps=%llu riops=%u wiops=%u",
* restrictions in the whole hierarchy and allows them to bypass
* blk-throttle.
*/
- blkg_for_each_descendant_pre(blkg, pos_css, ctx.blkg)
+ blkg_for_each_descendant_pre(blkg, pos_css, tg_to_blkg(tg))
tg_update_has_rules(blkg_to_tg(blkg));
/*
tg_update_disptime(tg);
throtl_schedule_next_dispatch(sq->parent_sq, true);
}
+}
+
+static ssize_t tg_set_conf(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off, bool is_u64)
+{
+ struct blkcg *blkcg = css_to_blkcg(of_css(of));
+ struct blkg_conf_ctx ctx;
+ struct throtl_grp *tg;
+ int ret;
+ u64 v;
+ ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx);
+ if (ret)
+ return ret;
+
+ ret = -EINVAL;
+ if (sscanf(ctx.body, "%llu", &v) != 1)
+ goto out_finish;
+ if (!v)
+ v = -1;
+
+ tg = blkg_to_tg(ctx.blkg);
+
+ if (is_u64)
+ *(u64 *)((void *)tg + of_cft(of)->private) = v;
+ else
+ *(unsigned int *)((void *)tg + of_cft(of)->private) = v;
+
+ tg_conf_updated(tg);
+ ret = 0;
+out_finish:
blkg_conf_finish(&ctx);
- return nbytes;
+ return ret ?: nbytes;
}
static ssize_t tg_set_conf_u64(struct kernfs_open_file *of,
return tg_set_conf(of, buf, nbytes, off, false);
}
-static struct cftype throtl_files[] = {
+static struct cftype throtl_legacy_files[] = {
{
.name = "throttle.read_bps_device",
.private = offsetof(struct throtl_grp, bps[READ]),
},
{
.name = "throttle.io_service_bytes",
- .private = offsetof(struct tg_stats_cpu, service_bytes),
- .seq_show = tg_print_cpu_rwstat,
+ .private = (unsigned long)&blkcg_policy_throtl,
+ .seq_show = blkg_print_stat_bytes,
},
{
.name = "throttle.io_serviced",
- .private = offsetof(struct tg_stats_cpu, serviced),
- .seq_show = tg_print_cpu_rwstat,
+ .private = (unsigned long)&blkcg_policy_throtl,
+ .seq_show = blkg_print_stat_ios,
+ },
+ { } /* terminate */
+};
+
+static u64 tg_prfill_max(struct seq_file *sf, struct blkg_policy_data *pd,
+ int off)
+{
+ struct throtl_grp *tg = pd_to_tg(pd);
+ const char *dname = blkg_dev_name(pd->blkg);
+ char bufs[4][21] = { "max", "max", "max", "max" };
+
+ if (!dname)
+ return 0;
+ if (tg->bps[READ] == -1 && tg->bps[WRITE] == -1 &&
+ tg->iops[READ] == -1 && tg->iops[WRITE] == -1)
+ return 0;
+
+ if (tg->bps[READ] != -1)
+ snprintf(bufs[0], sizeof(bufs[0]), "%llu", tg->bps[READ]);
+ if (tg->bps[WRITE] != -1)
+ snprintf(bufs[1], sizeof(bufs[1]), "%llu", tg->bps[WRITE]);
+ if (tg->iops[READ] != -1)
+ snprintf(bufs[2], sizeof(bufs[2]), "%u", tg->iops[READ]);
+ if (tg->iops[WRITE] != -1)
+ snprintf(bufs[3], sizeof(bufs[3]), "%u", tg->iops[WRITE]);
+
+ seq_printf(sf, "%s rbps=%s wbps=%s riops=%s wiops=%s\n",
+ dname, bufs[0], bufs[1], bufs[2], bufs[3]);
+ return 0;
+}
+
+static int tg_print_max(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_max,
+ &blkcg_policy_throtl, seq_cft(sf)->private, false);
+ return 0;
+}
+
+static ssize_t tg_set_max(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct blkcg *blkcg = css_to_blkcg(of_css(of));
+ struct blkg_conf_ctx ctx;
+ struct throtl_grp *tg;
+ u64 v[4];
+ int ret;
+
+ ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx);
+ if (ret)
+ return ret;
+
+ tg = blkg_to_tg(ctx.blkg);
+
+ v[0] = tg->bps[READ];
+ v[1] = tg->bps[WRITE];
+ v[2] = tg->iops[READ];
+ v[3] = tg->iops[WRITE];
+
+ while (true) {
+ char tok[27]; /* wiops=18446744073709551616 */
+ char *p;
+ u64 val = -1;
+ int len;
+
+ if (sscanf(ctx.body, "%26s%n", tok, &len) != 1)
+ break;
+ if (tok[0] == '\0')
+ break;
+ ctx.body += len;
+
+ ret = -EINVAL;
+ p = tok;
+ strsep(&p, "=");
+ if (!p || (sscanf(p, "%llu", &val) != 1 && strcmp(p, "max")))
+ goto out_finish;
+
+ ret = -ERANGE;
+ if (!val)
+ goto out_finish;
+
+ ret = -EINVAL;
+ if (!strcmp(tok, "rbps"))
+ v[0] = val;
+ else if (!strcmp(tok, "wbps"))
+ v[1] = val;
+ else if (!strcmp(tok, "riops"))
+ v[2] = min_t(u64, val, UINT_MAX);
+ else if (!strcmp(tok, "wiops"))
+ v[3] = min_t(u64, val, UINT_MAX);
+ else
+ goto out_finish;
+ }
+
+ tg->bps[READ] = v[0];
+ tg->bps[WRITE] = v[1];
+ tg->iops[READ] = v[2];
+ tg->iops[WRITE] = v[3];
+
+ tg_conf_updated(tg);
+ ret = 0;
+out_finish:
+ blkg_conf_finish(&ctx);
+ return ret ?: nbytes;
+}
+
+static struct cftype throtl_files[] = {
+ {
+ .name = "max",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = tg_print_max,
+ .write = tg_set_max,
},
{ } /* terminate */
};
}
static struct blkcg_policy blkcg_policy_throtl = {
- .pd_size = sizeof(struct throtl_grp),
- .cftypes = throtl_files,
+ .dfl_cftypes = throtl_files,
+ .legacy_cftypes = throtl_legacy_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_reset_stats_fn = throtl_pd_reset_stats,
+ .pd_free_fn = throtl_pd_free,
};
-bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
+bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
+ struct bio *bio)
{
- struct throtl_data *td = q->td;
struct throtl_qnode *qn = NULL;
- struct throtl_grp *tg;
+ struct throtl_grp *tg = blkg_to_tg(blkg ?: q->root_blkg);
struct throtl_service_queue *sq;
bool rw = bio_data_dir(bio);
- struct blkcg *blkcg;
bool throttled = false;
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
/* see throtl_charge_bio() */
- if (bio->bi_rw & REQ_THROTTLED)
+ if ((bio->bi_rw & REQ_THROTTLED) || !tg->has_rules[rw])
goto out;
- /*
- * A throtl_grp pointer retrieved under rcu can be used to access
- * basic fields like stats and io rates. If a group has no rules,
- * just update the dispatch stats in lockless manner and return.
- */
- rcu_read_lock();
- blkcg = bio_blkcg(bio);
- tg = throtl_lookup_tg(td, blkcg);
- if (tg) {
- if (!tg->has_rules[rw]) {
- throtl_update_dispatch_stats(tg_to_blkg(tg),
- bio->bi_iter.bi_size, bio->bi_rw);
- goto out_unlock_rcu;
- }
- }
-
- /*
- * Either group has not been allocated yet or it is not an unlimited
- * IO group
- */
spin_lock_irq(q->queue_lock);
- tg = throtl_lookup_create_tg(td, blkcg);
- if (unlikely(!tg))
+
+ if (unlikely(blk_queue_bypass(q)))
goto out_unlock;
sq = &tg->service_queue;
out_unlock:
spin_unlock_irq(q->queue_lock);
-out_unlock_rcu:
- rcu_read_unlock();
out:
/*
* As multiple blk-throtls may stack in the same issue path, we
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 / linux-drm-fsl-dcu.git / blobdiff