From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f179.google.com (mail-pf0-f179.google.com [209.85.192.179]) by dpdk.org (Postfix) with ESMTP id D51772C0C for ; Wed, 13 Apr 2016 01:38:54 +0200 (CEST) Received: by mail-pf0-f179.google.com with SMTP id n1so22589686pfn.2 for ; Tue, 12 Apr 2016 16:38:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=versa-networks-com.20150623.gappssmtp.com; s=20150623; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=tWzsA/L5JyBU63VMWB4lp39F1ZtfJH6XnTDqcaRr+Gc=; b=0hExLOZmee9XeTaSUtEzl2uK8HpIr3Q+WhuL07Q+BtTqw7OEShXiG+pQfDe4/jmK9c uQDLuTqiMM4zN0x6XlCWpq2HtO+Kpb4CXBwIhACsp2CeNX7+wKPIdXHlphWTFSgwdLAj W2ujvJkruIo5zKcgif/S0pwwq5ErMJyVAjHevWXfrMBWH516/uTqv6OHc3e2wsrP60So 2i68P5CHZmi+2+Od/+UHP1dxbwkTFUvawIwmxIrUeYscFs+du7tbLU5yuV5KnZyYUtAJ GYvcj9oA+fYl08akyUGtGoxY/ZWSYVM46m20j8zRy7WOVTadsu2u7qg1hxUM97rv7oKX v3DA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=tWzsA/L5JyBU63VMWB4lp39F1ZtfJH6XnTDqcaRr+Gc=; b=Fy8E2axSudE5dNOB4Tu6pP5P8Q0PNxvaKKKnf2aLx5sY6e/wZu6+wsqwCKZs0dodPu 5MYOjjnrdEvDEdlcb3MySzJJT6XpWMVw3yw/E9pravevvdAkgWIw82R5lvnOA4eJXdYX AZUF4KrdpRitpyENlzdKM0clfScdUbGq5hfOkwqL1R4DpmyleeM62lBosA4iX4wZ4vZV BHfT3qrVipG99mbqQUVLU7C8Cwg7JutmTArsfdD8Z4owNdoXpNl5dz2ywQ4JCdDPLIJw GPpUFwS0/vqL7yn8Nd48tlVaGvf9pOpl1tu3PmwXpsjMAgwZ2qLnefI/2qqsN4332jox r0ZA== X-Gm-Message-State: AOPr4FU8vfl2TcCVtb2ptxWF0Sj6nHZQGlwfLPucn2oZueJMTaAhJvq2hAhpPzN2W6Q00hij X-Received: by 10.98.19.2 with SMTP id b2mr8446536pfj.93.1460504334155; Tue, 12 Apr 2016 16:38:54 -0700 (PDT) Received: from [10.0.0.48] (70-35-56-62.static.wiline.com. [70.35.56.62]) by smtp.gmail.com with ESMTPSA id b82sm46091511pfd.89.2016.04.12.16.38.52 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 12 Apr 2016 16:38:53 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: "Sridhar.V.Iyer" In-Reply-To: <3EB4FA525960D640B5BDFFD6A3D89126479A0AF8@IRSMSX108.ger.corp.intel.com> Date: Tue, 12 Apr 2016 16:38:52 -0700 Cc: "dev@dpdk.org" Content-Transfer-Encoding: quoted-printable Message-Id: <552ECCE7-B985-4E84-BBDD-A21AB1D5D3E1@versa-networks.com> References: <3EB4FA525960D640B5BDFFD6A3D89126479A0AF8@IRSMSX108.ger.corp.intel.com> To: "Dumitrescu, Cristian" X-Mailer: Apple Mail (2.3124) Subject: Re: [dpdk-dev] Packet drops at lower tc transmit-rates. X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Apr 2016 23:38:55 -0000 Hi Cristian, Thanks for the response. >=20 > Another potential workaround could be to change the pipe TC credit = update logic from straightforward re-initialization to a slightly more = tuned strategy that, in some cases, keeps some of the existing credits, = so that the existing credits are not completely lost but some of them = (value capped to 1x MTU) are carried forward: >=20 > pipe->tc_credits[i] =3D (params->tc_credits_per_period[i] < = MTU)? > ((pipe->tc_credits[i] % MTU) + = params->tc_credits_per_period[i]) :=20 > params->tc_credits_per_period[i]; >=20 > This would give the chance to the pipe TC credits to accumulate and = become greater than the MTU every few periods and a packet to be = transmitted for this pipe TC. Of course, this strategy needs to be = further developed. This approach seemed to give the apparent rate closest to the configured = rate, irrespective of the MTU, the packet size, or the min packet size. = I=E2=80=99ll use the port->mtu to influence the tc_credits_per_period = accumulation. Is there any particular reason why a token bucket was not used for = traffic classes? Regards, Sridhar=