From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:46238 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750930AbdJ0Enl (ORCPT ); Fri, 27 Oct 2017 00:43:41 -0400 From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig Cc: Omar Sandoval , Bart Van Assche , Roman Pen , Hannes Reinecke , Ming Lei Subject: [PATCH V2 0/2] block: remove unnecessary RESTART Date: Fri, 27 Oct 2017 12:43:28 +0800 Message-Id: <20171027044330.11921-1-ming.lei@redhat.com> Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org Hi Jens, The 1st patch removes the RESTART for TAG-SHARED because SCSI handles it by itself, and not necessary to waste CPU to do the expensive RESTART. And Roman Pen reported that this RESTART cuts half of IOPS in his case. The 2nd patch removes the RESTART when .get_budget returns BLK_STS_RESOURCE, and this RESTART is handled by SCSI's RESTART(scsi_end_request()) too. Ming Lei (2): blk-mq: don't handle TAG_SHARED in restart blk-mq: don't restart queue when .get_budget returns BLK_STS_RESOURCE block/blk-mq-sched.c | 123 ++++----------------------------------------- block/blk-mq-sched.h | 2 +- block/blk-mq.c | 8 +--- 3 files changed, 27 insertions(+), 106 deletions(-) -- 2.9.5