Hi Chunguang, On Mon, Jan 10, 2022 at 04:29:23PM +0800, brookxu wrote: > From: Chunguang Xu <brookxu@xxxxxxxxxxx> > > After commit 900e08075202("block: move queue enter logic into > blk_mq_submit_bio()"), submit_bio_checks() moved to __submit_bio_fops() > and blk_mq_submit_bio(). The IOs go through blk_mq_submit_bio() > may be splited before entering blk-throtl, so we need to check > whether the BIO is throttled, and only update the io_split_cnt > for the THROTTLED bio to avoid double charge. Today Jens has merged the patch[1] of "block: don't protect submit_bio_checks by q_usage_counter", so the behavior is switched back to previous behavior: running bio check before calling blk_mq_submit_bio() or ->submit_bio(). Then looks your patch isn't needn't any more. [1] https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git/commit/?h=for-5.17/block&id=9d497e2941c30a060ba62d5485b3bc9d91ffb09e Thanks, Ming