Hi, this series contain a few patches to fix problem when on the default hierarchy, corrent comment and so on. More detail can be found in respective changelogs. Thanks. --- V1->V2: -Thanks for the review and advice from Tejun. The corrected comment of "blk-throttle: correct stale comment in throtl_pd_init" and the solution of "blk-throttle: Fix that bps of child could exceed bps limited in parent" are from reply of Tejun. -Collect Ack from Tejun. -Fix the compile problem when CONFIG_BLK_DEV_THROTTLING_LOW is set. -Drop "blk-throttle: Limit whole system if root group is configured when on the default hierarchy", "blk-throttle: remove unnecessary check for validation of limit index" and "blk-throttle: remove unused variable td in tg_update_has_rules" -Add "blk-throttle: correct stale comment in throtl_pd_init" and "blk-throttle: avoid dead code in throtl_hierarchy_can_upgrade" -Use solution that set the BIO_BPS_THROTTLED flag only when the bio traversed the entire tree to fix that bps of child could exceed bps limited in parent in patch 2/10. -Improve the description and comment of most commits. --- Kemeng Shi (10): blk-throttle: correct stale comment in throtl_pd_init blk-throttle: Fix that bps of child could exceed bps limited in parent blk-throttle: ignore cgroup without io queued in blk_throtl_cancel_bios blk-throttle: correct calculation of wait time in tg_may_dispatch blk-throttle: simpfy low limit reached check in throtl_tg_can_upgrade blk-throttle: fix typo in comment of throtl_adjusted_limit blk-throttle: remove incorrect comment for tg_last_low_overflow_time blk-throttle: remove repeat check of elapsed time from last upgrade in throtl_hierarchy_can_downgrade blk-throttle: Use more siutable time_after check for update of slice_start blk-throttle: avoid dead code in throtl_hierarchy_can_upgrade block/blk-throttle.c | 104 +++++++++++++++++++++++-------------------- 1 file changed, 56 insertions(+), 48 deletions(-) -- 2.30.0