From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f178.google.com (mail-wi0-f178.google.com [209.85.212.178]) by dpdk.org (Postfix) with ESMTP id 50B4CC348 for ; Sat, 6 Jun 2015 23:05:38 +0200 (CEST) Received: by wiwd19 with SMTP id d19so50614856wiw.0 for ; Sat, 06 Jun 2015 14:05:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=SaXtSgtztr4UIlhcKTg3F4gEiUwSK0M1dTbj/040kLM=; b=YGbpkHx/KKqK8vBqx+gGTf/pa2DajIjUR3J2fHau74DGgbTjMjqNOJ0cN4+vhk+pVy j+P4YalYTa1UeXoQnpL0ULbmNW3R5wr7XgQSJNoEezMyapz0yQzbQXoNg2hNItK62ucv 0swRlpp5rBjEM03quFFDI4H7ZjGqqCIDdOsDy2ao6PNOpFPSehNcZyfgTwfNLgh7F+CE 3GdsaGMscwFHqMqCCfADT3R0WEBfeOD3lxq9qzJ07ZYePNAiMZu9bZKUgOp2faEyeZOT 6tBTG1FJUYsDSM5ubh0Rc9ENQbKClN0Z2QGHX/WT55cpPeHoSZ2SpOODhx2sT9JonsuO qeqQ== X-Gm-Message-State: ALoCoQncnCgNAs1JvLvrYs+hemL/rHCzlCxKmy96qn+KOB2L2j3OTEIl3eAQOC2JuQmOg/hj7Se0 MIME-Version: 1.0 X-Received: by 10.194.185.236 with SMTP id ff12mr13555570wjc.134.1433624738154; Sat, 06 Jun 2015 14:05:38 -0700 (PDT) Received: by 10.27.140.72 with HTTP; Sat, 6 Jun 2015 14:05:38 -0700 (PDT) In-Reply-To: <3EB4FA525960D640B5BDFFD6A3D8912632372F7E@IRSMSX108.ger.corp.intel.com> References: <3EB4FA525960D640B5BDFFD6A3D8912632372F7E@IRSMSX108.ger.corp.intel.com> Date: Sat, 6 Jun 2015 17:05:38 -0400 Message-ID: From: Michael Sardo To: "Dumitrescu, Cristian" Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] 4 Traffic classes per Pipe limitation 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: Sat, 06 Jun 2015 21:05:38 -0000 Hello Cristian, Are the slides shown in that video available? They're very helpful. -Mike On Fri, Jun 5, 2015 at 4:50 PM, Dumitrescu, Cristian < cristian.dumitrescu@intel.com> wrote: > Hi Avinash, > > > -----Original Message----- > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Yeddula, Avinash > > Sent: Friday, June 5, 2015 6:06 PM > > To: dev@dpdk.org > > Subject: [dpdk-dev] 4 Traffic classes per Pipe limitation > > > > Hi, > > This is related to the QOS scheduler functionality provided by dpdk. > > > > I see a limit on the number of traffic classes to be 4. I'm exploring > the > > available options to increase that limit to 8. > > Yes, there are 4x traffic classes (scheduled in strict priority), but each > traffic class has 4x queues (scheduled using WFQ); for big weight ratios > between queues (e.g. 1:4 or 1:8, etc), WFQ becomes very similar to strict > priority, a king of strict priority without starvation. So the 16x queues > per pipe can be considered 16x sub-traffic-classes. > > You might want to watch this video on DPDK QoS: > https://youtu.be/_PPklkWGugs > > > > > This is what I found when I researched on this topic. > > The limitation on number's of TC (and pipes) comes from the number of > > bits available. Since the QoS code overloads the 32 bit RSS field in > > the mbuf there isn't enough bits to a lot. But then again if you add lots > > of pipes or subports the memory footprint gets huge. > > It is not that simple. The number of 4x traffic classes in deeply built > into the implementation for performance reasons. Increasing the number of > bits allocated to traffic class in mbuf->sched would not help. > > > > > Any more info or suggestions on increasing the limit to 8 ? > > Yes, look at the 16x pipe queues as 16x (sub)traffic classes. > > > > Thanks > > -Avinash >