From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D686C282CE for ; Tue, 4 Jun 2019 08:51:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A23124BEC for ; Tue, 4 Jun 2019 08:51:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727027AbfFDIvI (ORCPT ); Tue, 4 Jun 2019 04:51:08 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:58818 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726637AbfFDIvI (ORCPT ); Tue, 4 Jun 2019 04:51:08 -0400 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 5FA1FB9A7CF393333ABD; Tue, 4 Jun 2019 16:50:19 +0800 (CST) Received: from [127.0.0.1] (10.202.227.238) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.439.0; Tue, 4 Jun 2019 16:50:12 +0800 Subject: Re: [PATCH 0/9] blk-mq/scsi: convert private reply queue into blk_mq hw queue To: Ming Lei , Jens Axboe , , , "Martin K . Petersen" References: <20190531022801.10003-1-ming.lei@redhat.com> CC: James Bottomley , Bart Van Assche , Hannes Reinecke , Don Brace , Kashyap Desai , "Sathya Prakash" , Christoph Hellwig , chenxiang From: John Garry Message-ID: Date: Tue, 4 Jun 2019 09:49:54 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <20190531022801.10003-1-ming.lei@redhat.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.238] X-CFilter-Loop: Reflected Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 31/05/2019 03:27, Ming Lei wrote: > Hi, > > The 1st patch introduces support hostwide tags for multiple hw queues > via the simplest approach to share single 'struct blk_mq_tags' instance > among all hw queues. In theory, this way won't cause any performance drop. > Even small IOPS improvement can be observed on random IO on > null_blk/scsi_debug. > > By applying the hostwide tags for MQ, we can convert some SCSI driver's > private reply queue into generic blk-mq hw queue, then at least two > improvement can be obtained: > > 1) the private reply queue maping can be removed from drivers, since the > mapping has been implemented as generic API in blk-mq core > > 2) it helps to solve the generic managed IRQ race[1] during CPU hotplug > in generic way, otherwise we have to re-invent new way to address the > same issue for these drivers using private reply queue. > > > [1] https://lore.kernel.org/linux-block/20190527150207.11372-1-ming.lei@redhat.com/T/#m6d95e2218bdd712ffda8f6451a0bb73eb2a651af > > Any comment and test feedback are appreciated. > > Thanks, > Ming > Hi Ming, I think that we'll wait for a v2 to test this, since you gave some updated patch for the megaraid performance testing. Thanks, John > Hannes Reinecke (1): > scsi: Add template flag 'host_tagset' > > Ming Lei (8): > blk-mq: allow hw queues to share hostwide tags > block: null_blk: introduce module parameter of 'g_host_tags' > scsi_debug: support host tagset > scsi: introduce scsi_cmnd_hctx_index() > scsi: hpsa: convert private reply queue to blk-mq hw queue > scsi: hisi_sas_v3: convert private reply queue to blk-mq hw queue > scsi: megaraid: convert private reply queue to blk-mq hw queue > scsi: mp3sas: convert private reply queue to blk-mq hw queue > > block/blk-mq-debugfs.c | 1 + > block/blk-mq-sched.c | 8 +++ > block/blk-mq-tag.c | 6 ++ > block/blk-mq.c | 14 ++++ > block/elevator.c | 5 +- > drivers/block/null_blk_main.c | 6 ++ > drivers/scsi/hisi_sas/hisi_sas.h | 2 +- > drivers/scsi/hisi_sas/hisi_sas_main.c | 36 +++++----- > drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 46 +++++-------- > drivers/scsi/hpsa.c | 49 ++++++-------- > drivers/scsi/megaraid/megaraid_sas_base.c | 50 +++++--------- > drivers/scsi/megaraid/megaraid_sas_fusion.c | 4 +- > drivers/scsi/mpt3sas/mpt3sas_base.c | 74 ++++----------------- > drivers/scsi/mpt3sas/mpt3sas_base.h | 3 +- > drivers/scsi/mpt3sas/mpt3sas_scsih.c | 17 +++++ > drivers/scsi/scsi_debug.c | 3 + > drivers/scsi/scsi_lib.c | 2 + > include/linux/blk-mq.h | 1 + > include/scsi/scsi_cmnd.h | 15 +++++ > include/scsi/scsi_host.h | 3 + > 20 files changed, 168 insertions(+), 177 deletions(-) >