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-rw-r--r--block/blk-throttle.c82
1 files changed, 81 insertions, 1 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 62984fc..6300f3e 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -22,6 +22,9 @@ static int throtl_quantum = 32;
#define DFL_THROTL_SLICE_HD (HZ / 10)
#define DFL_THROTL_SLICE_SSD (HZ / 50)
#define MAX_THROTL_SLICE (HZ)
+#define DFL_IDLE_THRESHOLD_SSD (1000L) /* 1 ms */
+#define DFL_IDLE_THRESHOLD_HD (100L * 1000) /* 100 ms */
+#define MAX_IDLE_TIME (5L * 1000 * 1000) /* 5 s */
static struct blkcg_policy blkcg_policy_throtl;
@@ -154,6 +157,11 @@ struct throtl_grp {
/* When did we start a new slice */
unsigned long slice_start[2];
unsigned long slice_end[2];
+
+ unsigned long last_finish_time; /* ns / 1024 */
+ unsigned long checked_last_finish_time; /* ns / 1024 */
+ unsigned long avg_idletime; /* ns / 1024 */
+ unsigned long idletime_threshold; /* us */
};
struct throtl_data
@@ -468,6 +476,11 @@ static void throtl_pd_init(struct blkg_policy_data *pd)
if (cgroup_subsys_on_dfl(io_cgrp_subsys) && blkg->parent)
sq->parent_sq = &blkg_to_tg(blkg->parent)->service_queue;
tg->td = td;
+
+ if (blk_queue_nonrot(td->queue))
+ tg->idletime_threshold = DFL_IDLE_THRESHOLD_SSD;
+ else
+ tg->idletime_threshold = DFL_IDLE_THRESHOLD_HD;
}
/*
@@ -1644,6 +1657,21 @@ static unsigned long tg_last_low_overflow_time(struct throtl_grp *tg)
return ret;
}
+static bool throtl_tg_is_idle(struct throtl_grp *tg)
+{
+ /*
+ * cgroup is idle if:
+ * - single idle is too long, longer than a fixed value (in case user
+ * configure a too big threshold) or 4 times of slice
+ * - average think time is more than threshold
+ */
+ unsigned long time = jiffies_to_usecs(4 * tg->td->throtl_slice);
+
+ time = min_t(unsigned long, MAX_IDLE_TIME, time);
+ return (ktime_get_ns() >> 10) - tg->last_finish_time > time ||
+ tg->avg_idletime > tg->idletime_threshold;
+}
+
static bool throtl_tg_can_upgrade(struct throtl_grp *tg)
{
struct throtl_service_queue *sq = &tg->service_queue;
@@ -1843,6 +1871,19 @@ static void throtl_downgrade_check(struct throtl_grp *tg)
tg->last_io_disp[WRITE] = 0;
}
+static void blk_throtl_update_idletime(struct throtl_grp *tg)
+{
+ unsigned long now = ktime_get_ns() >> 10;
+ unsigned long last_finish_time = tg->last_finish_time;
+
+ if (now <= last_finish_time || last_finish_time == 0 ||
+ last_finish_time == tg->checked_last_finish_time)
+ return;
+
+ tg->avg_idletime = (tg->avg_idletime * 7 + now - last_finish_time) >> 3;
+ tg->checked_last_finish_time = last_finish_time;
+}
+
bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
struct bio *bio)
{
@@ -1851,6 +1892,7 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
struct throtl_service_queue *sq;
bool rw = bio_data_dir(bio);
bool throttled = false;
+ int ret;
WARN_ON_ONCE(!rcu_read_lock_held());
@@ -1863,6 +1905,13 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
if (unlikely(blk_queue_bypass(q)))
goto out_unlock;
+ ret = bio_associate_current(bio);
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+ if (ret == 0 || ret == -EBUSY)
+ bio->bi_cg_private = tg;
+#endif
+ blk_throtl_update_idletime(tg);
+
sq = &tg->service_queue;
again:
@@ -1923,7 +1972,6 @@ again:
tg->last_low_overflow_time[rw] = jiffies;
- bio_associate_current(bio);
tg->td->nr_queued[rw]++;
throtl_add_bio_tg(bio, qn, tg);
throttled = true;
@@ -1952,6 +2000,20 @@ out:
return throttled;
}
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+void blk_throtl_bio_endio(struct bio *bio)
+{
+ struct throtl_grp *tg;
+
+ tg = bio->bi_cg_private;
+ if (!tg)
+ return;
+ bio->bi_cg_private = NULL;
+
+ tg->last_finish_time = ktime_get_ns() >> 10;
+}
+#endif
+
/*
* Dispatch all bios from all children tg's queued on @parent_sq. On
* return, @parent_sq is guaranteed to not have any active children tg's
@@ -2035,6 +2097,7 @@ int blk_throtl_init(struct request_queue *q)
td->limit_index = LIMIT_MAX;
td->low_upgrade_time = jiffies;
td->low_downgrade_time = jiffies;
+
/* activate policy */
ret = blkcg_activate_policy(q, &blkcg_policy_throtl);
if (ret)
@@ -2053,6 +2116,8 @@ void blk_throtl_exit(struct request_queue *q)
void blk_throtl_register_queue(struct request_queue *q)
{
struct throtl_data *td;
+ struct cgroup_subsys_state *pos_css;
+ struct blkcg_gq *blkg;
td = q->td;
BUG_ON(!td);
@@ -2065,6 +2130,21 @@ void blk_throtl_register_queue(struct request_queue *q)
/* if no low limit, use previous default */
td->throtl_slice = DFL_THROTL_SLICE_HD;
#endif
+
+ /*
+ * some tg are created before queue is fully initialized, eg, nonrot
+ * isn't initialized yet
+ */
+ rcu_read_lock();
+ blkg_for_each_descendant_post(blkg, pos_css, q->root_blkg) {
+ struct throtl_grp *tg = blkg_to_tg(blkg);
+
+ if (blk_queue_nonrot(q))
+ tg->idletime_threshold = DFL_IDLE_THRESHOLD_SSD;
+ else
+ tg->idletime_threshold = DFL_IDLE_THRESHOLD_HD;
+ }
+ rcu_read_unlock();
}
#ifdef CONFIG_BLK_DEV_THROTTLING_LOW