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=-2.3 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 1D039C352A3 for ; Tue, 11 Feb 2020 11:53:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E704C20714 for ; Tue, 11 Feb 2020 11:53:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728628AbgBKLxI (ORCPT ); Tue, 11 Feb 2020 06:53:08 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:2407 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727436AbgBKLxH (ORCPT ); Tue, 11 Feb 2020 06:53:07 -0500 Received: from lhreml703-cah.china.huawei.com (unknown [172.18.7.106]) by Forcepoint Email with ESMTP id 388B67DD042C72863D18; Tue, 11 Feb 2020 11:53:06 +0000 (GMT) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by lhreml703-cah.china.huawei.com (10.201.108.44) with Microsoft SMTP Server (TLS) id 14.3.408.0; Tue, 11 Feb 2020 11:53:05 +0000 Received: from [127.0.0.1] (10.202.226.45) 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; Tue, 11 Feb 2020 11:53:05 +0000 Subject: Re: [PATCH] scsi: Delete scsi_use_blk_mq From: John Garry To: Bart Van Assche , , CC: , References: <1581355992-139274-1-git-send-email-john.garry@huawei.com> <3795ab1d-5282-458b-6199-91e3def32463@acm.org> <2e2ead7d-503e-3881-b837-7c689a4d44c6@huawei.com> Message-ID: Date: Tue, 11 Feb 2020 11:53:04 +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: <2e2ead7d-503e-3881-b837-7c689a4d44c6@huawei.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.45] X-ClientProxiedBy: lhreml720-chm.china.huawei.com (10.201.108.71) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/02/2020 11:50, John Garry wrote: > On 10/02/2020 22:37, Bart Van Assche wrote: >> On 2/10/20 9:33 AM, John Garry wrote: >>> -module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | >>> S_IRUGO); >> > > Hi Bart, > >> Will this change cause trouble to shell scripts that set or read this >> parameter (/sys/module/scsi_mod/parameters/use_blk_mq)? > > The entry in Documentation/admin-guide/kernel-parameters.txt is gone for > 2 years now. > > And it is not an archaic module param, it was introduced 6 years ago. As > such, I'd say that if a shell script was setup to access this parameter, > then it would prob also pre-check if it exists and gracefully accept > that it may not. > > I will also note that there is still scsi_sysfs.c:show_use_blk_mq(), > which would stay. > > What will the >> impact be on systems where scsi_mod.use_blk_mq=Y is passed by GRUB to >> the kernel at boot time, e.g. because it has been set in the >> GRUB_CMDLINE_LINUX variable in /etc/default/grub? > > The kernel should any params that does not recognize. ^ ignore > >> > > Having said all that, I don't feel too strongly about deleting this - > it's only some tidy-up. > > Thanks, > John > > .