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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D1A28C282DD for ; Thu, 9 Jan 2020 18:17:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD9642072A for ; Thu, 9 Jan 2020 18:17:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388437AbgAISRL (ORCPT ); Thu, 9 Jan 2020 13:17:11 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:2247 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388436AbgAISRK (ORCPT ); Thu, 9 Jan 2020 13:17:10 -0500 Received: from lhreml706-cah.china.huawei.com (unknown [172.18.7.107]) by Forcepoint Email with ESMTP id 04CBC5B1AC3C133F9644; Thu, 9 Jan 2020 18:17:09 +0000 (GMT) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by lhreml706-cah.china.huawei.com (10.201.108.47) with Microsoft SMTP Server (TLS) id 14.3.408.0; Thu, 9 Jan 2020 18:17:08 +0000 Received: from [127.0.0.1] (10.202.226.43) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Thu, 9 Jan 2020 18:17:08 +0000 Subject: Re: [PATCH 09/11] megaraid_sas: switch fusion adapters to MQ To: Hannes Reinecke , Sumit Saxena CC: "Martin K. Petersen" , Jens Axboe , Christoph Hellwig , James Bottomley , Ming Lei , Linux SCSI List , , Hannes Reinecke References: <20191202153914.84722-1-hare@suse.de> <20191202153914.84722-10-hare@suse.de> <339f089f-26aa-1cbe-416b-67809ea6791f@huawei.com> <0a39f7ec-88ec-f00c-6256-858b40efce64@suse.de> From: John Garry Message-ID: Date: Thu, 9 Jan 2020 18:17:07 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <0a39f7ec-88ec-f00c-6256-858b40efce64@suse.de> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.43] X-ClientProxiedBy: lhreml729-chm.china.huawei.com (10.201.108.80) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 09/01/2020 15:19, Hannes Reinecke wrote: > On 1/9/20 12:55 PM, John Garry wrote: >> On 09/12/2019 10:10, Sumit Saxena wrote: >>> On Mon, Dec 2, 2019 at 9:09 PM Hannes Reinecke wrote: >>>> >>>> Fusion adapters can steer completions to individual queues, and >>>> we now have support for shared host-wide tags. >>>> So we can enable multiqueue support for fusion adapters and >>>> drop the hand-crafted interrupt affinity settings. >>> >>> Hi Hannes, >>> >>> Ming Lei also proposed similar changes in megaraid_sas driver some >>> time back and it had resulted in performance drop- >>> https://patchwork.kernel.org/patch/10969511/ >>> >>> So, we will do some performance tests with this patch and update you. >>> >> >> Hi Sumit, >> >> I was wondering if you had a chance to do this test yet? >> >> It would be good to know, so we can try to progress this work. >> >> @Hannes, This shared sbitmap work now seems to conflict with Jens work >> on tag caching >> https://lore.kernel.org/linux-block/20200107163037.31745-1-axboe@kernel.dk/T/#t, >> but should be resolvable AFAICS (v1, anyway, which I checked). Anway, we >> seem to have stalled, which I feared... >> > Thanks for the reminder. > That was a topic I was wanting to discuss at LSF; will be sending a > topic then. Alright, but I am not really sure what else we need to wait months to discuss, unless this shared sbitmap approach is rejected and/or testing on other HBAs shows unsatisfactory performance. To summarize, as I see, we have 3 topics to tackle: - shared tags - block hotplug improvement - Ming Lei had said that he will post another version of https://lore.kernel.org/linux-block/20191128020205.GB3277@ming.t460p/ - https://patchwork.kernel.org/cover/10967071/ - I'm not sure what's happening on that, but thought that it was somewhat straightforward. If there's something else I've missed, then let me know. Cheers, John