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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 552E0C433F5 for ; Tue, 22 Mar 2022 11:33:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234238AbiCVLey (ORCPT ); Tue, 22 Mar 2022 07:34:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52320 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234228AbiCVLeu (ORCPT ); Tue, 22 Mar 2022 07:34:50 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3224165B6; Tue, 22 Mar 2022 04:33:22 -0700 (PDT) Received: from fraeml743-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4KN8SY1MNkz67pCt; Tue, 22 Mar 2022 19:31:09 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml743-chm.china.huawei.com (10.206.15.224) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 22 Mar 2022 12:33:19 +0100 Received: from [10.47.85.68] (10.47.85.68) 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 15.1.2308.21; Tue, 22 Mar 2022 11:33:18 +0000 Message-ID: Date: Tue, 22 Mar 2022 11:33:17 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH 01/11] blk-mq: Add blk_mq_init_queue_ops() To: Christoph Hellwig CC: , , , , , , , , , , , , , References: <1647945585-197349-1-git-send-email-john.garry@huawei.com> <1647945585-197349-2-git-send-email-john.garry@huawei.com> <20220322111848.GA29270@lst.de> From: John Garry In-Reply-To: <20220322111848.GA29270@lst.de> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.85.68] X-ClientProxiedBy: lhreml730-chm.china.huawei.com (10.201.108.81) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/03/2022 11:18, Christoph Hellwig wrote: > On Tue, Mar 22, 2022 at 06:39:35PM +0800, John Garry wrote: >> Add an API to allocate a request queue which accepts a custom set of >> blk_mq_ops for that request queue. >> >> The reason which we may want custom ops is for queuing requests which we >> don't want to go through the normal queuing path. > > Eww. I really do not think we should do separate ops per queue, as that > is going to get us into a deep mess eventually. > Yeah... so far (here) it works out quite nicely, as we don't need to change the SCSI blk mq ops nor allocate a scsi_device - everything is just separate. The other method mentioned previously was to add the request "reserved" flag and add new paths in scsi_queue_rq() et al to handle this, but that gets messy. Any other ideas ...? Cheers, John