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 B5E44C636D3 for ; Tue, 31 Jan 2023 03:06:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229634AbjAaDGP (ORCPT ); Mon, 30 Jan 2023 22:06:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37376 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229918AbjAaDGO (ORCPT ); Mon, 30 Jan 2023 22:06:14 -0500 Received: from out30-43.freemail.mail.aliyun.com (out30-43.freemail.mail.aliyun.com [115.124.30.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 662993029A; Mon, 30 Jan 2023 19:06:12 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VaUqCZz_1675134368; Received: from 30.221.149.193(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VaUqCZz_1675134368) by smtp.aliyun-inc.com; Tue, 31 Jan 2023 11:06:10 +0800 Message-ID: <82545b5f-2b9e-61ab-9e67-866e2a492904@linux.alibaba.com> Date: Tue, 31 Jan 2023 11:06:07 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [PATCH net-next v6 1/7] net/smc: remove locks smc_client_lgr_pending and smc_server_lgr_pending Content-Language: en-US To: Wenjia Zhang , jaka@linux.ibm.com, kgraul@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org References: <1669453422-38152-1-git-send-email-alibuda@linux.alibaba.com> <1669453422-38152-2-git-send-email-alibuda@linux.alibaba.com> <2ad147d3-b127-b192-c2a5-29fa704cf3a1@linux.alibaba.com> From: "D. Wythe" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On 1/31/23 5:10 AM, Wenjia Zhang wrote: > > > On 30.01.23 11:51, D. Wythe wrote: >> >> >> On 1/30/23 4:37 PM, Wenjia Zhang wrote: >>> >>> >>> On 29.01.23 16:11, D. Wythe wrote: >>>> >>>> >>>> On 11/26/22 5:03 PM, D.Wythe wrote: >>>>> From: "D. Wythe" >>>>> >>>>> This patch attempts to remove locks named smc_client_lgr_pending and >>>>> smc_server_lgr_pending, which aim to serialize the creation of link >>>>> group. However, once link group existed already, those locks are >>>>> meaningless, worse still, they make incoming connections have to be >>>>> queued one after the other. >>>>> >>>>> Now, the creation of link group is no longer generated by competition, >>>>> but allocated through following strategy. >>>>> >>>> >>>> >>>> Hi, all >>>> >>>> I have noticed that there may be some difficulties in the advancement of this series of patches. >>>> I guess the main problem is to try remove the global lock in this patch, the risks of removing locks >>>> do harm to SMC-D, at the same time, this patch of removing locks is also a little too complex. >>>> >>>> So, I am considering that we can temporarily delay the advancement of this patch. We can works on >>>> other patches first. Other patches are either simple enough or have no obvious impact on SMC-D. >>>> >>>> What do you think? >>>> >>>> Best wishes. >>>> D. Wythe >>>> >>>> >>> Hi D. Wythe, >>> >>> that sounds good. Thank you for your consideration about SMC-D! >> >> Hi Wenjia, >> >> Thanks for your reply. >> >>> Removing locks is indeed a big issue, those patches make us difficult to accept without thoroughly testing in every corner. >>> >>> Best >>> Wenjia >> >> What do you mean by those patches? My plan is to delete the first patch in this series, >> that is, 'remove locks smc_client_lgr_pending and smc_server_lgr_pending', while other patches >> should be retained. >> >> They has almost nothing impact on SMC-D or simple enough to be tested. If you agree with this, >> I can then issue the next version as soon as possible to remove the first patch, and I think >> we can quickly promote those patches. >> >> Thanks. >> Wenjia >> > Except for the removing locks of smc_client_lgr_pending and smc_server_lgr_pending, I'm still not that sure if running SMC_LLC_FLOW_RKEY concurrently could make the communication between our Linux and z/OS broken, that we can not test currently, though I really like this idea. Hi, Wenjia This is really a situation that I hadn't considered before, and I'm afraid it can be a problem, if implementation of z/OS do need to process SMC_LLC_FLOW_RKEY one by one, and i guess it's very possible. > Sure, you can send the next version, I'll find a way to verify it. Whatever, I will issue the next patches with first patch removed, and if we cannot pass the compatibility test with z/OS, I think we have to give up the patch tried to running SMC_LLC_FLOW_RKEY concurrently. Fortunately, we have discussed the possibility of protocol extension before. If the patch tried to running SMC_LLC_FLOW_RKEY concurrently cannot be promoted temporarily, we can also promote it again after the protocol extension is completed. Thanks. D. Wythe > > > >> >> >>