From: Yu Kuai yukuai3@huawei.com
hulk inclusion category: bugfix bugzilla: 46357 CVE: NA
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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 Reviewed-by: Tao Hou houtao1@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- block/blk-throttle.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index caee658609d7..c7b4f905feb5 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -568,6 +568,7 @@ static void throtl_pd_online(struct blkg_policy_data *pd) 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; @@ -588,6 +589,11 @@ static void blk_throtl_update_limit_valid(struct throtl_data *td)
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)