blk_throtl_update_limit_valid() will search for descendants to see if
'LIMIT_LOW' of bps/iops and READ/WRITE is nonzero. However, they're always
zero if CONFIG_BLK_DEV_THROTTLING_LOW is not set, furthermore, a lot of
time will be wasted to iterate descendants.
Thus do nothing in blk_throtl_update_limit_valid() in such situation.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
tg_update_has_rules(tg);
}
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
static void blk_throtl_update_limit_valid(struct throtl_data *td)
{
struct cgroup_subsys_state *pos_css;
td->limit_valid[LIMIT_LOW] = low_valid;
}
+#else
+static inline void blk_throtl_update_limit_valid(struct throtl_data *td)
+{
+}
+#endif
static void throtl_upgrade_state(struct throtl_data *td);
static void throtl_pd_offline(struct blkg_policy_data *pd)