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 C8687C433E0 for ; Tue, 16 Jun 2020 19:27:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A00F5208B3 for ; Tue, 16 Jun 2020 19:27:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730349AbgFPT1k (ORCPT ); Tue, 16 Jun 2020 15:27:40 -0400 Received: from mga18.intel.com ([134.134.136.126]:23540 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730269AbgFPT1j (ORCPT ); Tue, 16 Jun 2020 15:27:39 -0400 IronPort-SDR: AkyFKd/E97A+/I65rfINP6EYBi9uYhYh1pzC2IHJpWWpbP1AJuttyPpVBBZgpz/pmOkHwM0MOa +JRiCEPVnaBA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jun 2020 12:27:38 -0700 IronPort-SDR: X1d2gdq4I4K3pT9jV9GHxwgNGeuicUngZN6mFETxVj5yJoK+zaHFaVkNOPAHv1KqmftsOR/2ap 6ScDHRtROnHQ== X-IronPort-AV: E=Sophos;i="5.73,519,1583222400"; d="scan'208";a="449955767" Received: from ddalessa-mobl.amr.corp.intel.com (HELO [10.254.207.107]) ([10.254.207.107]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jun 2020 12:27:36 -0700 Subject: Re: [PATCH v3 for-next 07/16] IB/ipoib: Increase ipoib Datagram mode MTU's upper limit To: Ira Weiny Cc: Leon Romanovsky , Nathan Chancellor , Jason Gunthorpe , dledford@redhat.com, linux-rdma@vger.kernel.org, Mike Marciniszyn , Sadanand Warrier , Kaike Wan References: <20200511155337.173205.77558.stgit@awfm-01.aw.intel.com> <20200511160618.173205.23053.stgit@awfm-01.aw.intel.com> <20200527040350.GA3118979@ubuntu-s3-xlarge-x86> <9e9147ad-6d7c-9381-72f3-dc2f3d0723fd@intel.com> <20200601135722.GE4872@ziepe.ca> <20200616005650.GA1347657@ubuntu-n2-xlarge-x86> <20200616062534.GB2141420@unreal> <53f86386-780d-4b06-9848-f8a6eede57ee@intel.com> <20200616192112.GG4160762@iweiny-DESK2.sc.intel.com> From: Dennis Dalessandro Message-ID: Date: Tue, 16 Jun 2020 15:27:34 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200616192112.GG4160762@iweiny-DESK2.sc.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 6/16/2020 3:21 PM, Ira Weiny wrote: > On Tue, Jun 16, 2020 at 03:14:51PM -0400, Dennis Dalessandro wrote: >> On 6/16/2020 2:25 AM, Leon Romanovsky wrote: >>> On Mon, Jun 15, 2020 at 05:56:50PM -0700, Nathan Chancellor wrote: >>>> On Mon, Jun 01, 2020 at 10:57:22AM -0300, Jason Gunthorpe wrote: >>>>> On Mon, Jun 01, 2020 at 09:48:47AM -0400, Dennis Dalessandro wrote: >>>>> >>>>>> They should probably all be in "enum ib_mtu". Jason any issues with us donig >>>>>> that? I can't for certain recall the real reason they were kept separate in >>>>>> the first place. >>>>> >>>>> It is probably OK >>>>> >>>>> Jason >>>> >>>> I don't mind taking a wack at this if you guys are too busy (I'm rather >>>> tired of seeing the warning across all of my builds). However, I am >>>> wondering how far should this be unwound? Should 'enum opa_mtu' be >>>> collapsed into 'enum ib_mtu' and then all of the opa conversion >>>> functions be eliminated in favor of the ib ones? It looks like >>>> OPA_MTU_8192 and OPA_MTU_10240 are used in a few places within >>>> drivers/infiniband/hw/hfi1, should all of those instances be converted >>>> over to IB_MTU_* and the defines at the top of >>>> drivers/infiniband/hw/hfi1/hfi.h be eliminated? >> >> My opinion is yes. >> >>> We rather keep separation due to logic separation. >> >> To be fair, "you" rather. Not we. I'd like some others to weigh in here. >> Increasing the available MTUs an an enum just makes sense. Why does it >> matter if IB doesn't need them right now. Maybe someday. >> >>> While ib_* defines come from IBTA and interoperable across different >>> devices and vendors, opa_* definitions are Intel proprietary ones used >>> for the product that was canceled. >> >> But does it hurt to have more potentially available? Can you please explain >> the technical reason here? > > The problem is that the IBTA _may_ define those enums to mean something > different in the future. Hopefully, the Intel representatives within the IBTA > would try to make them compatible but I don't know that 10K 'fits' with the > IBTA's future. 8K seems like a reasonable extension for the IBTA but again we > as Linux developers can't say that will happen for sure. We just don't control > what the IBTA does in that regard. > I guess I buy that. However I believe I have seen it claimed in the past that we aren't the IBTA, we are the Linux kernel and can do what we think makes sense. But to be honest I don't feel strongly, and I'm not gonna argue strongly one way or the other. -Denny