From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ming Lei Subject: [PATCH 0/2] block/SCSI MQ: two RESTART related patches Date: Tue, 17 Oct 2017 13:04:16 +0800 Message-ID: <20171017050418.22555-1-ming.lei@redhat.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig Cc: Bart Van Assche , linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, Omar Sandoval , John Garry , Ming Lei List-Id: linux-scsi@vger.kernel.org Hi Jens, The 1st patch runs idle hctx after dealy in scsi_mq_get_budget(), so that we can keep same behaviour with before, and it can be thought as a fix. The 2nd patch cleans up RESTART, and removes handling for TAG_SHARED from current blk-mq's RESTART mechanism because SCSI_MQ can covers its restart by itself, so that no need to handle TAG_SHARED in blk-mq RESTART. And >20% IOPS boost is observed in my rand read test over scsi_debug. John, please test this two patches and see if it may improve your SAS IO performance, and you can find the two patches in the following branch: https://github.com/ming1/linux/commits/blk_mq_improve_restart_V1 Ming Lei (2): SCSI: run idle hctx after delay in scsi_mq_get_budget() blk-mq: don't handle TAG_SHARED in restart block/blk-mq-sched.c | 78 +++---------------------------------------------- drivers/scsi/scsi_lib.c | 13 +++++++-- 2 files changed, 14 insertions(+), 77 deletions(-) -- 2.9.5