From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752811AbdI3LrR (ORCPT ); Sat, 30 Sep 2017 07:47:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34074 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752157AbdI3LrQ (ORCPT ); Sat, 30 Sep 2017 07:47:16 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 37E5F37EEF Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=ming.lei@redhat.com From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig , Mike Snitzer , dm-devel@redhat.com Cc: Bart Van Assche , Laurence Oberman , linux-kernel@vger.kernel.org, Omar Sandoval , Ming Lei Subject: [PATCH 0/5] dm-rq: improve sequential I/O performance Date: Sat, 30 Sep 2017 19:46:47 +0800 Message-Id: <20170930114652.32441-1-ming.lei@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Sat, 30 Sep 2017 11:47:16 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, This 1st one patch removes one log message which can be triggered very easily. The 2nd patch removes the workaround of blk_mq_delay_run_hw_queue() in case of requeue, this way isn't necessary, and more worse, it makes BLK_MQ_S_SCHED_RESTART not working, and degarde I/O performance. The 3rd patch return DM_MAPIO_REQUEUE to dm-rq if underlying request allocation fails, then we can return BLK_STS_RESOURCE from dm-rq to blk-mq, so that blk-mq can hold the requests to be dequeued. The 4th patch is a pre-patch for the 5th one, becasue even though underlying request allocation succeeds, its queue may be busy and we can get this feedback from blk_insert_cloned_request() now. This patch trys to cache the allocated request so that it may be reused in next dispatch to underlying queue. The 5th patch improves sequential I/O performance by returning STS_RESOURCE if underlying queue is busy. In the commit log of the 5th patch, I/O IOPS data is provided and we can see sequential I/O performance is improved a lot with this patchset. This patchset depends on the following two patchset: [1] [PATCH V5 0/7] blk-mq-sched: improve sequential I/O performance(part 1) https://marc.info/?l=linux-block&m=150676854821077&w=2 [2] [PATCH V5 0/8] blk-mq: improve bio merge for none scheduler https://marc.info/?l=linux-block&m=150677085521416&w=2 Any comments are welcome! Thanks, Ming Ming Lei (5): dm-mpath: remove annoying message of 'blk_get_request() returned -11' dm-mpath: don't call blk_mq_delay_run_hw_queue() in case of BLK_STS_RESOURCE dm-mpath: return DM_MAPIO_REQUEUE in case of rq allocation failure dm-mpath: cache ti->clone during requeue dm-rq: improve I/O merge by dealing with underlying STS_RESOURCE block/blk-mq.c | 17 +--------------- drivers/md/dm-mpath.c | 51 ++++++++++++++++++++++++++++++++++------------ drivers/md/dm-rq.c | 56 +++++++++++++++++++++++++++++++++++++-------------- 3 files changed, 80 insertions(+), 44 deletions(-) -- 2.9.5