From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f181.google.com (mail-yw1-f181.google.com [209.85.128.181]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5B9F033E4 for ; Mon, 27 Jun 2022 16:25:32 +0000 (UTC) Received: by mail-yw1-f181.google.com with SMTP id 00721157ae682-3178acf2a92so90928407b3.6 for ; Mon, 27 Jun 2022 09:25:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=iAKbjN/cfvJPKH/ugt3ybbCNo8kM3ZVPMiqHDruEifg=; b=RbOhXfsOqEDMRENO38mrpSrXxxDYigIIL0iGHtE8xCdU+DUoAXKdt3N63SVhhS9bj+ vE2UFnU2Zf22D0Ic4nq6JinMhf0Rjku6ueYypwbmUvx4P4JuaSisipOX5K8x7shK1He1 Sk/Gw+rOyqohify/KsKnjlLAviBaC9Vo8OtebbrJ5fNeCpt6gqGuma5db02XQdqbiN/9 1Ag08g5+15n3bnIIqqmQnHSAO7DPvRcyWTP8d5sJSPb1SSC2xw97478ugS1gXgiYTaO6 gI/ywCGguebiSzo0OFIw5YW2u7W3NCNfDYEl+SNNPS0N8N6VKJwV+q1Cupj+aXeASM/M Lang== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=iAKbjN/cfvJPKH/ugt3ybbCNo8kM3ZVPMiqHDruEifg=; b=qHflplHrPiuTjltH2JMqOGEDsOwhulb7rxgv0JgR6IuG7p0x0b9+QuYBl/bQUEbGju XDwt8+M/rupQ51cb8C/XSA/aifBJRnLUbpuCxLRzp+I2WAGGDkb7q+0f/DzNdLShSSmc ZduqeWFdI7hDXQuh/CyT0wWuuQh5uYOpGh6OWLUTRwjCL4nUZltP98d/3Mo2OBVrgmVN 7RLsLWK90lfAmRjXlFjOQJe1or+OTZVX/5nSb2ppxdR/zVhv5M0mM/WXLg+vvAQo8CIX JjrEQCnbnm8LEDo19ADlBEiLmXDOvao4XjtNZi+RjBkc4nBtIG+dH/iaXien14jCD9w8 U0RQ== X-Gm-Message-State: AJIora8RA4OcmM6pAK5nhbynDnYPHi3qEIDxwFj1ylykpYlo1Jq45tI+ SjVcGom5wea6BuA7j2s/FK8b+b6iICtxXkbtLbv0BA== X-Google-Smtp-Source: AGRyM1vH55ursM9GjUkBbRtmBX4QDoHDlEEpNJpUs5A6vX12LOpEiXhq4y8+47q5BzoyFRCpabSxvoZUSxVB0BpYoPY= X-Received: by 2002:a81:bd51:0:b0:31b:db72:88a1 with SMTP id n17-20020a81bd51000000b0031bdb7288a1mr3087923ywk.208.1656347131154; Mon, 27 Jun 2022 09:25:31 -0700 (PDT) Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20220623185730.25b88096@kernel.org> <20220624070656.GE79500@shbuild999.sh.intel.com> <20220624144358.lqt2ffjdry6p5u4d@google.com> <20220625023642.GA40868@shbuild999.sh.intel.com> <20220627023812.GA29314@shbuild999.sh.intel.com> <20220627123415.GA32052@shbuild999.sh.intel.com> <20220627151258.GB20878@shbuild999.sh.intel.com> In-Reply-To: <20220627151258.GB20878@shbuild999.sh.intel.com> From: Shakeel Butt Date: Mon, 27 Jun 2022 09:25:20 -0700 Message-ID: Subject: Re: [net] 4890b686f4: netperf.Throughput_Mbps -69.4% regression To: Feng Tang Cc: Eric Dumazet , Linux MM , Andrew Morton , Roman Gushchin , Michal Hocko , Johannes Weiner , Muchun Song , Jakub Kicinski , Xin Long , Marcelo Ricardo Leitner , kernel test robot , Soheil Hassas Yeganeh , LKML , network dev , linux-s390@vger.kernel.org, MPTCP Upstream , "linux-sctp @ vger . kernel . org" , lkp@lists.01.org, kbuild test robot , Huang Ying , Xing Zhengjun , Yin Fengwei , Ying Xu Content-Type: text/plain; charset="UTF-8" On Mon, Jun 27, 2022 at 8:25 AM Feng Tang wrote: > > On Mon, Jun 27, 2022 at 07:52:55AM -0700, Shakeel Butt wrote: > > On Mon, Jun 27, 2022 at 5:34 AM Feng Tang wrote: > > > Yes, 1% is just around noise level for a microbenchmark. > > > > > > I went check the original test data of Oliver's report, the tests was > > > run 6 rounds and the performance data is pretty stable (0Day's report > > > will show any std deviation bigger than 2%) > > > > > > The test platform is a 4 sockets 72C/144T machine, and I run the > > > same job (nr_tasks = 25% * nr_cpus) on one CascadeLake AP (4 nodes) > > > and one Icelake 2 sockets platform, and saw 75% and 53% regresson on > > > them. > > > > > > In the first email, there is a file named 'reproduce', it shows the > > > basic test process: > > > > > > " > > > use 'performane' cpufre governor for all CPUs > > > > > > netserver -4 -D > > > modprobe sctp > > > netperf -4 -H 127.0.0.1 -t SCTP_STREAM_MANY -c -C -l 300 -- -m 10K & > > > netperf -4 -H 127.0.0.1 -t SCTP_STREAM_MANY -c -C -l 300 -- -m 10K & > > > netperf -4 -H 127.0.0.1 -t SCTP_STREAM_MANY -c -C -l 300 -- -m 10K & > > > (repeat 36 times in total) > > > ... > > > > > > " > > > > > > Which starts 36 (25% of nr_cpus) netperf clients. And the clients number > > > also matters, I tried to increase the client number from 36 to 72(50%), > > > and the regression is changed from 69.4% to 73.7% > > > > > > > Am I understanding correctly that this 69.4% (or 73.7%) regression is > > with cgroup v2? > > Yes. > > > Eric did the experiments on v2 but on real hardware where the > > performance impact was negligible. > > > > BTW do you see similar regression for tcp as well or just sctp? > > Yes, I run TCP_SENDFILE case with 'send_size'==10K, it hits a > 70%+ regressioin. > Thanks Feng. I think we should start with squeezing whatever we can from layout changes and then try other approaches like increasing batch size or something else. I can take a stab at this next week. thanks, Shakeel