blk-throttle: configure bps/iops limit for cgroup in low limit

each queue will have a state machine. Initially queue is in LIMIT_LOW state, which means all cgroups will be throttled according to their low limit. After all cgroups with low limit cross the limit, the queue state gets upgraded to LIMIT_MAX state. For max limit, cgroup will use the limit configured by user. For low limit, cgroup will use the minimal value between low limit and max limit configured by user. If the minimal value is 0, which means the cgroup doesn't configure low limit, we will use max limit to throttle the cgroup and the cgroup is ready to upgrade to LIMIT_MAX Signed-off-by: Shaohua Li <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
josf · Mar 28, 2017 · b22c417 · b22c417
1 parent cd5ab1b
commit b22c417
Showing 1 changed file with 18 additions and 2 deletions.
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
@@ -212,12 +212,28 @@ static struct throtl_data *sq_to_td(struct throtl_service_queue *sq)
 
 static uint64_t tg_bps_limit(struct throtl_grp *tg, int rw)
 {
-	return tg->bps[rw][tg->td->limit_index];
+	struct blkcg_gq *blkg = tg_to_blkg(tg);
+	uint64_t ret;
+
+	if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent)
+		return U64_MAX;
+	ret = tg->bps[rw][tg->td->limit_index];
+	if (ret == 0 && tg->td->limit_index == LIMIT_LOW)
+		return tg->bps[rw][LIMIT_MAX];
+	return ret;
 }
 
 static unsigned int tg_iops_limit(struct throtl_grp *tg, int rw)
 {
-	return tg->iops[rw][tg->td->limit_index];
+	struct blkcg_gq *blkg = tg_to_blkg(tg);
+	unsigned int ret;
+
+	if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent)
+		return UINT_MAX;
+	ret = tg->iops[rw][tg->td->limit_index];
+	if (ret == 0 && tg->td->limit_index == LIMIT_LOW)
+		return tg->iops[rw][LIMIT_MAX];
+	return ret;
 }
 
 /**