From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 1AF92426A6 for ; Mon, 2 Oct 2023 23:21:38 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id D3821402C7; Mon, 2 Oct 2023 23:21:37 +0200 (CEST) Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) by mails.dpdk.org (Postfix) with ESMTP id 922B340294 for ; Mon, 2 Oct 2023 23:21:36 +0200 (CEST) Received: by mail-pl1-f181.google.com with SMTP id d9443c01a7336-1c60778a3bfso1969505ad.1 for ; Mon, 02 Oct 2023 14:21:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1696281695; x=1696886495; darn=dpdk.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=pvFEO3wmKrJftsvrs2ecn9JcpfPTxSDZvCxSXVxlyYU=; b=sfqVgwmgQZhj3bMq9qTJtNa5uicniVkmC/yDSR4EJ3D7sUhF6pNXCkxfOoVAM5dzQO FGdX9fXi4Nn9kztazrVGeV+ShJt6llJ91QMa4oKZ3B2mj0zRnEtsIdM2fVLtuS6YYTIM ugm2bn2vqs8IBChTHUjdxAlKLMlTEBgtPip+Sz+0zjGlmwLH7NKK1C8tuYGNhLv3QrKD /84ZBx/E/NVKHEtWXC95kuHazQ8zLjJ2zoesp/uinYpXWoqvKqhi6z5qMbvog3ddFt6C BUecucn54arB1tqXH6k90wZLcOYRJdDWstNAoCiW5NFPL20PZntAnVV96HwSSRpXxNc9 hlQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696281695; x=1696886495; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=pvFEO3wmKrJftsvrs2ecn9JcpfPTxSDZvCxSXVxlyYU=; b=qQHOBv8/BM4qmLq4VvJylSvUqK7l5r2hfIT7eiKpPGNpKiQdy2w3amaQ3PSwgoRxKv H7KVLof7JrvbiaSVU3xDMPiaJHcTex9M8V1nCEHJmV39yGpMUlGILRX1M2wL3+LHr71t NDxzQNH7ERNGb2YSHeqcLcdhB+xHKjqKZLrO5uQDwijhkT7An8aTvtVSGehLZMhwPqC2 Q9g6Z569NGGxVRzCBa+xUU6IBy8Z0gY35/pCfK8//OZkS62Z+ZXTesEVm4SWC6gNimFh qNr/SUNnqD43mJrmA7ej+KqgUxyFaSjc9g8nREeQcHjQcYyOgI3UA+CiNy2hxjsyR8q8 QGrQ== X-Gm-Message-State: AOJu0YyzgTJzimflTNJzuNu4UJCLmfzCneSKal40Va5E28aMB1wX0uGQ byOW95UiNu1puJyM85Lrgq3V1Q== X-Google-Smtp-Source: AGHT+IFZspcjGJ9CH/c/DZfVxrMOGJP4JBR2B0IMoLMSZmCO4lzkdrOR/ptJxP52jyRZKzg8ikbYhg== X-Received: by 2002:a17:902:d4c3:b0:1c7:5708:1077 with SMTP id o3-20020a170902d4c300b001c757081077mr9079783plg.66.1696281695599; Mon, 02 Oct 2023 14:21:35 -0700 (PDT) Received: from hermes.local (204-195-126-68.wavecable.com. [204.195.126.68]) by smtp.gmail.com with ESMTPSA id s18-20020a17090330d200b001c6052152fdsm17948960plc.50.2023.10.02.14.21.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Oct 2023 14:21:35 -0700 (PDT) Date: Mon, 2 Oct 2023 14:21:33 -0700 From: Stephen Hemminger To: Antonio Di Bacco Cc: users@dpdk.org Subject: Re: tap device speed Message-ID: <20231002142133.27590624@hermes.local> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org On Mon, 2 Oct 2023 21:13:03 +0200 Antonio Di Bacco wrote: > I'm doing a test where we have a couple of tap devices, the two > devices are seen by testpmd that is setup in forward mode. > > On the linux side, the two tap devices are confined in different > network namespaces and in one namespace we have an iperf server while > on the other namespace the iperf client sending either UDP or TCP. > > I expected a bandwidth in the range of few gpbs while the actual > measured bandwidth is a few gigabits. > > I suppose I need to configure the tap devices with optimized > parameters but I don't know where to look for advice. > > If I try to use the loopback interface I can get something 40 gbps > with a command like this: > > iperf -c 127.0.0.1 -u -i 1 -b 40g -t 10 -l 40000 > > . Sorry TAP device is inherently slow. It requires copies to/from Linux kernel. You are doing well if you get 1 million packets per second. One thing to check is that checksum is not being done twice.