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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,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 25CFBC433E0 for ; Fri, 12 Mar 2021 15:21:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C1DAF64FF3 for ; Fri, 12 Mar 2021 15:21:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231857AbhCLPVO (ORCPT ); Fri, 12 Mar 2021 10:21:14 -0500 Received: from smtp-fw-4101.amazon.com ([72.21.198.25]:58383 "EHLO smtp-fw-4101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232005AbhCLPVK (ORCPT ); Fri, 12 Mar 2021 10:21:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1615562471; x=1647098471; h=to:cc:references:from:message-id:date:mime-version: in-reply-to:content-transfer-encoding:subject; bh=fXChBcwn3i8+I8FRgnwJ2UacpPT+Q/2Jk1d/TX9xTNU=; b=L0qZH24LODcV0+LiANRVDuSW6Nh/cAwob0GWznYD2R2okmjlIj+eSWmW anaJJlIalLJTFxycJgj98wwlhWAyst0Z7a/uH8XdQTyXo/ZXdcU0GrBLa sx7c39Nrhi4SP5iUag2WdRHaHVA78zb0rt55SY3pi/y+Gz6lh8P1O7gJW A=; IronPort-HdrOrdr: A9a23:jABeqaDMkSulc2PlHekZ55DYdL4zR+YMi2QD/UoZc20zTuWzkc eykPMHkSLlkTp5YgBHpfmsGomlBUnd+5l8/JULMd6ZNjXOlWO0IOhZnOjf6hL6HSmWzI5g/I NBV4Q7N9HqF1h9iq/BgTWQN9o72tGI/OSJqI7lvhVQZDpnYa1h8At1YzzzeiZLbTNbDpk0Ho f03LsjmxOcfx0sH6CGL0hAceyGg9HQjprpbVo9GhY75GC14Q+A2frVFR6X2xtbfhFu5fMZ8W bDmxHk/anLiZyG4y6Z+WnU4ZFb3OHk18IGPsqRkcIYQw+Cti+YIL9sUbGDozw5ydvA1GoX X-IronPort-AV: E=Sophos;i="5.81,243,1610409600"; d="scan'208";a="92520097" Subject: Re: [net-next 1/2] xen-netback: add module parameter to disable ctrl-ring Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-2b-859fe132.us-west-2.amazon.com) ([10.43.8.2]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 12 Mar 2021 15:18:11 +0000 Received: from EX13D12EUA002.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan2.pdx.amazon.com [10.236.137.194]) by email-inbound-relay-2b-859fe132.us-west-2.amazon.com (Postfix) with ESMTPS id CF1DD220186; Fri, 12 Mar 2021 15:18:09 +0000 (UTC) Received: from 147dda3ee008.ant.amazon.com (10.43.162.213) by EX13D12EUA002.ant.amazon.com (10.43.165.103) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 12 Mar 2021 15:18:06 +0000 To: Andrew Lunn CC: , , , , , References: <20210311225944.24198-1-andyhsu@amazon.com> From: "Hsu, Chiahao" Message-ID: Date: Fri, 12 Mar 2021 16:18:02 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [10.43.162.213] X-ClientProxiedBy: EX13D04UWB002.ant.amazon.com (10.43.161.133) To EX13D12EUA002.ant.amazon.com (10.43.165.103) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Andrew Lunn 於 2021/3/12 15:52 寫道: > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe. > > > > On Thu, Mar 11, 2021 at 10:59:44PM +0000, ChiaHao Hsu wrote: >> In order to support live migration of guests between kernels >> that do and do not support 'feature-ctrl-ring', we add a >> module parameter that allows the feature to be disabled >> at run time, instead of using hardcode value. >> The default value is enable. > Hi ChiaHao > > There is a general dislike for module parameters. What other mechanisms > have you looked at? Would an ethtool private flag work? > > Andrew Hi Andrew, I can survey other mechanisms, however before I start doing that, could you share more details about what the problem is with using module parameters? thanks. ChiaHao