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 CA9C5C43217 for ; Thu, 20 Oct 2022 07:24:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229979AbiJTHYu (ORCPT ); Thu, 20 Oct 2022 03:24:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230054AbiJTHYs (ORCPT ); Thu, 20 Oct 2022 03:24:48 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 826F2317C2; Thu, 20 Oct 2022 00:24:43 -0700 (PDT) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29K6bqaI011765; Thu, 20 Oct 2022 07:24:38 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=qAonZ3btuT45t59SGJ8U5rXkCFpJMdwLzYQrnXcW5pk=; b=nyywbQJVMI1lXmcavkkejz4mvK3ROpKDAsd8lKQuPYXM8V5pMVXeRStZE/4ZdsKDI7gN ZHL64VpGZEdWx/VHaDrLHx5ra0iOWxN7q/vw0rWzsNV/7Lqvu/7D79ZqlkYk5D06GN+l UypvPOpwfWkChl2LCTNYrL68NkC6BVh89slSgbaV402jOsn4M2xm5HcI/aVFEW1bue9e rP+37Lep/9AWC+PniW1Bue7iimJe0AZzwD4EONHtAWKjd3hAmndPvYhO9JO9W0mqHe+9 zxAd8wIGE45dOfgqhCmNYzw8w7YCAfhyTvP3Ewh9LXinU8hi/st3e/cA7dG3XD+poGYT OQ== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3kb0yh1mh7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 20 Oct 2022 07:24:37 +0000 Received: from m0098420.ppops.net (m0098420.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 29K6cPJ4014760; Thu, 20 Oct 2022 07:24:37 GMT Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3kb0yh1mgs-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 20 Oct 2022 07:24:37 +0000 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 29K7LPrK030643; Thu, 20 Oct 2022 07:24:35 GMT Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by ppma03ams.nl.ibm.com with ESMTP id 3k7mg98fg6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 20 Oct 2022 07:24:35 +0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 29K7OXv034668814 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 20 Oct 2022 07:24:33 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 64663AE045; Thu, 20 Oct 2022 07:24:33 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CB669AE055; Thu, 20 Oct 2022 07:24:32 +0000 (GMT) Received: from [9.171.15.191] (unknown [9.171.15.191]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 20 Oct 2022 07:24:32 +0000 (GMT) Message-ID: <492ada12-4e46-bb45-bc4b-1962e4530764@linux.ibm.com> Date: Thu, 20 Oct 2022 09:24:32 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.3.3 Subject: Re: [PATCH net-next v3 00/10] optimize the parallelism of SMC-R connections Content-Language: en-US To: "D. Wythe" Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org References: <1666248232-63751-1-git-send-email-alibuda@linux.alibaba.com> <62001adc-129a-d477-c916-7a4cf2000553@linux.alibaba.com> From: Jan Karcher Organization: IBM - Network Linux on Z In-Reply-To: <62001adc-129a-d477-c916-7a4cf2000553@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: -QXIULwT6xitUyZdUZBZWBG3oyAIqtTH X-Proofpoint-ORIG-GUID: s_UB_NbW76xitksnTUQPCK0FZUoySiq5 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-10-20_02,2022-10-19_04,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 lowpriorityscore=0 mlxlogscore=999 priorityscore=1501 suspectscore=0 adultscore=0 impostorscore=0 bulkscore=0 spamscore=0 clxscore=1011 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2210200041 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 20.10.2022 09:00, D. Wythe wrote: > > Hi Jan, > > Sorry for the long delay, The main purpose of v3 is to put optimizes > also works on SMC-D, dues to the environment, > I can only tests it in SMC-R, so please help us to verify the stability > and functional in SMC-D, > Thanks a lot. > > If you have any problems, please let us know. > > Besides, PATCH bug fixes need to be reordered. After the code review > passes and the SMC-D test goes stable, I will adjust it > in next serial. Hi D. Wythe, no problem and thank you. I'm going to test your changes and let you know as soon as I'm done. - Jan > > > On 10/20/22 2:43 PM, D.Wythe wrote: >> From: "D.Wythe" >> >> This patch set attempts to optimize the parallelism of SMC-R connections, >> mainly to reduce unnecessary blocking on locks, and to fix exceptions >> that >> occur after thoses optimization. >> >> According to Off-CPU graph, SMC worker's off-CPU as that: >> >> smc_close_passive_work                  (1.09%) >>          smcr_buf_unuse                  (1.08%) >>                  smc_llc_flow_initiate   (1.02%) >> >> smc_listen_work                         (48.17%) >>          __mutex_lock.isra.11            (47.96%) >> >> >> An ideal SMC-R connection process should only block on the IO events >> of the network, but it's quite clear that the SMC-R connection now is >> queued on the lock most of the time. >> >> The goal of this patchset is to achieve our ideal situation where >> network IO events are blocked for the majority of the connection >> lifetime. >> >> There are three big locks here: >> >> 1. smc_client_lgr_pending & smc_server_lgr_pending >> >> 2. llc_conf_mutex >> >> 3. rmbs_lock & sndbufs_lock >> >> And an implementation issue: >> >> 1. confirm/delete rkey msg can't be sent concurrently while >> protocol allows indeed. >> >> Unfortunately,The above problems together affect the parallelism of >> SMC-R connection. If any of them are not solved. our goal cannot >> be achieved. >> >> After this patch set, we can get a quite ideal off-CPU graph as >> following: >> >> smc_close_passive_work                                  (41.58%) >>          smcr_buf_unuse                                  (41.57%) >>                  smc_llc_do_delete_rkey                  (41.57%) >> >> smc_listen_work                                         (39.10%) >>          smc_clc_wait_msg                                (13.18%) >>                  tcp_recvmsg_locked                      (13.18) >>          smc_listen_find_device                          (25.87%) >>                  smcr_lgr_reg_rmbs                       (25.87%) >>                          smc_llc_do_confirm_rkey         (25.87%) >> >> We can see that most of the waiting times are waiting for network IO >> events. This also has a certain performance improvement on our >> short-lived conenction wrk/nginx benchmark test: >> >> +--------------+------+------+-------+--------+------+--------+ >> |conns/qps     |c4    | c8   |  c16  |  c32   | c64  |  c200  | >> +--------------+------+------+-------+--------+------+--------+ >> |SMC-R before  |9.7k  | 10k  |  10k  |  9.9k  | 9.1k |  8.9k  | >> +--------------+------+------+-------+--------+------+--------+ >> |SMC-R now     |13k   | 19k  |  18k  |  16k   | 15k  |  12k   | >> +--------------+------+------+-------+--------+------+--------+ >> |TCP           |15k   | 35k  |  51k  |  80k   | 100k |  162k  | >> +--------------+------+------+-------+--------+------+--------+ >> >> The reason why the benefit is not obvious after the number of connections >> has increased dues to workqueue. If we try to change workqueue to >> UNBOUND, >> we can obtain at least 4-5 times performance improvement, reach up to >> half >> of TCP. However, this is not an elegant solution, the optimization of it >> will be much more complicated. But in any case, we will submit relevant >> optimization patches as soon as possible. >> >> Please note that the premise here is that the lock related problem >> must be solved first, otherwise, no matter how we optimize the workqueue, >> there won't be much improvement. >> >> Because there are a lot of related changes to the code, if you have >> any questions or suggestions, please let me know. >> >> Thanks >> D. Wythe >> >> v1 -> v2: >> >> 1. Fix panic in SMC-D scenario >> 2. Fix lnkc related hashfn calculation exception, caused by operator >> priority >> 3. Only wake up one connection if the lnk is not active >> 4. Delete obsolete unlock logic in smc_listen_work() >> 5. PATCH format, do Reverse Christmas tree >> 6. PATCH format, change all xxx_lnk_xxx function to xxx_link_xxx >> 7. PATCH format, add correct fix tag for the patches for fixes. >> 8. PATCH format, fix some spelling error >> 9. PATCH format, rename slow to do_slow >> >> v2 -> v3: >> >> 1. add SMC-D support, remove the concept of link cluster since SMC-D has >> no link at all. Replace it by lgr decision maker, who provides >> suggestions >> to SMC-D and SMC-R on whether to create new link group. >> >> 2. Fix the corruption problem described by PATCH 'fix application >> data exception' on SMC-D. >> >> D. Wythe (10): >>    net/smc: remove locks smc_client_lgr_pending and >>      smc_server_lgr_pending >>    net/smc: fix SMC_CLC_DECL_ERR_REGRMB without smc_server_lgr_pending >>    net/smc: allow confirm/delete rkey response deliver multiplex >>    net/smc: make SMC_LLC_FLOW_RKEY run concurrently >>    net/smc: llc_conf_mutex refactor, replace it with rw_semaphore >>    net/smc: use read semaphores to reduce unnecessary blocking in >>      smc_buf_create() & smcr_buf_unuse() >>    net/smc: reduce unnecessary blocking in smcr_lgr_reg_rmbs() >>    net/smc: replace mutex rmbs_lock and sndbufs_lock with rw_semaphore >>    net/smc: Fix potential panic dues to unprotected >>      smc_llc_srv_add_link() >>    net/smc: fix application data exception >> >>   net/smc/af_smc.c   |  70 ++++---- >>   net/smc/smc_core.c | 478 >> +++++++++++++++++++++++++++++++++++++++++++++++------ >>   net/smc/smc_core.h |  36 +++- >>   net/smc/smc_llc.c  | 277 ++++++++++++++++++++++--------- >>   net/smc/smc_llc.h  |   6 + >>   net/smc/smc_wr.c   |  10 -- >>   net/smc/smc_wr.h   |  10 ++ >>   7 files changed, 712 insertions(+), 175 deletions(-) >>