From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:33294 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752400AbeAOQ60 (ORCPT ); Mon, 15 Jan 2018 11:58:26 -0500 From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org Cc: Mike Snitzer , Christoph Hellwig , Ming Lei Subject: [PATCH V4 0/3] blk-mq: issue request directly for blk_insert_cloned_request Date: Tue, 16 Jan 2018 00:58:07 +0800 Message-Id: <20180115165810.2515-1-ming.lei@redhat.com> Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org Hi Guys, The 3 paches changes the blk-mq part of blk_insert_cloned_request(), in which we switch to blk_mq_try_issue_directly(), so that both dm-rq and blk-mq can get the dispatch result of underlying queue, and with this information, blk-mq can handle IO merge much better, then sequential I/O performance is improved much. In my dm-mpath over virtio-scsi test, this whole patchset improves sequential IO by 3X ~ 5X. V4: - remove dm patches which are in DM tree already - cleanup __blk_mq_issue_req as suggested by Jens V3: - rebase on the latest for-4.16/block of block tree - add missed pg_init_all_paths() in patch 1, according to Bart's review V2: - drop 'dm-mpath: cache ti->clone during requeue', which is a bit too complicated, and not see obvious performance improvement. - make change on blk-mq part cleaner Ming Lei (3): blk-mq: move actual issue into one helper blk-mq: return dispatch result to caller in blk_mq_try_issue_directly blk-mq: issue request directly for blk_insert_cloned_request block/blk-mq.c | 85 +++++++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 64 insertions(+), 21 deletions(-) -- 2.9.5