Hi Jens Please consider this patchset for 4.21. It refactors the code of issue request directly to unify the interface and make the code clearer and more readable. This patch set is rebased on the recent for-4.21/block and add the 1st patch which inserts the non-read-write request to hctx dispatch list to avoid to involve merge and io scheduler when bypass_insert is true, otherwise, inserting is ignored, BLK_STS_RESOURCE is returned and the caller will fail forever. The 2nd patch refactors the code of issue request directly to unify the helper interface which could handle all the cases. The 3rd patch make blk_mq_sched_insert_requests issue requests directly with 'bypass' false, then it needn't to handle the non-issued requests any more. The 4th patch replace and kill the blk_mq_request_issue_directly. V10: - address Jen's comment. - let blk_mq_try_issue_directly return actual result for case 'bypass == false'. (2/4) - use return value of blk_mq_try_issue_directly to identify whether the request is direct-issued successfully. (3/4) V9: - rebase on recent for-4.21/block - add 1st patch V8: - drop the original 2nd patch which try to insert requests into hctx->dispatch if quiesced or stopped. - remove two wrong 'unlikely' V7: - drop the original 3rd patch which try to ensure hctx to be ran on its mapped cpu in issueing directly path. V6: - drop original 1st patch to address Jen's comment - discard the enum mq_issue_decision and blk_mq_make_decision and use BLK_STS_* return values directly to address Jen's comment. (1/5) - add 'unlikely' in blk_mq_try_issue_directly (1/5) - refactor the 2nd and 3rd patch based on the new 1st patch. - reserve the unused_cookie in 4th and 5th patch V5: - rebase against Jens' for-4.21/block branch - adjust the order of patch04 and patch05 - add patch06 to replace and kill the one line blk_mq_request_bypass_insert - comment changes V4: - split the original patch 1 into two patches, 1st and 2nd patch currently - rename the mq_decision to mq_issue_decision - comment changes V3: - Correct the code about the case bypass_insert is true and io scheduler attached. The request still need to be issued in case above. (1/4) - Refactor the code to make code clearer. blk_mq_make_request is introduced to decide insert, end or just return based on the return value of .queue_rq and bypass_insert (1/4) - Add the 2nd patch. It introduce a new decision result which indicates to insert request with blk_mq_request_bypass_insert. - Modify the code to adapt the new patch 1. V2: - Add 1st and 2nd patch to refactor the code. Jianchao Wang (4) blk-mq: insert to hctx dispatch list when blk-mq: refactor the code of issue request directly blk-mq: issue directly with bypass 'false' in blk-mq: replace and kill blk_mq_request_issue_directly block/blk-core.c | 4 +- block/blk-mq-sched.c | 8 ++-- block/blk-mq.c | 127 +++++++++++++++++++++++---------------------------- block/blk-mq.h | 6 ++- 4 files changed, 68 insertions(+), 77 deletions(-) Thanks Jianchao
