From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Mattias_R=c3=b6nnblom?= Subject: Re: DSW eventdev and multi-process DPDK Date: Fri, 21 Dec 2018 19:59:08 +0100 Message-ID: <597ee5d1-6db1-54ee-36af-df28ef1654bb@ericsson.com> References: <2D68DFF2-08A3-403B-9570-43D4AD916FD2@paloaltonetworks.com> <8C05BF3C-5D90-4CD0-AA71-1B4C4324E53B@paloaltonetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit To: Venky Venkatesh , "dev@dpdk.org" Return-path: Received: from mail.lysator.liu.se (mail.lysator.liu.se [130.236.254.3]) by dpdk.org (Postfix) with ESMTP id 6E03B1BE65 for ; Fri, 21 Dec 2018 19:59:10 +0100 (CET) Received: from mail.lysator.liu.se (localhost [127.0.0.1]) by mail.lysator.liu.se (Postfix) with ESMTP id BB42B40014 for ; Fri, 21 Dec 2018 19:59:09 +0100 (CET) In-Reply-To: <8C05BF3C-5D90-4CD0-AA71-1B4C4324E53B@paloaltonetworks.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 2018-12-21 19:34, Venky Venkatesh wrote: > > > On 12/21/18, 10:24 AM, "Mattias Rönnblom" wrote: > > On 2018-12-21 06:13, Venky Venkatesh wrote: > > Hi, > > We are considering using a multi-process mode of the DPDK with the event generators and consumers being spread across multiple processes (on different cores). We are also considering using the DSW eventdev. Is the DSW designed for such a use case? If so, are there some restrictions and something specific that need to be done to make it work correctly? > > > > The purpose of an event device is to do dynamic load balancing across > multiple cores. Using the DPDK multiple-process support, with its > requirement of having unique, non-overlapping, core masks works against > or even defeats this purpose. > > [VV]: I don’t understand your last sentence. Suppose I am having multiple packet processing processes (each with a single thread and polling a disjoint set of queues) and each linked to DSW. Each process would invoke the enqueue which will be handled by the DSW linked to that process. Will the DSWs across these processes "collaborate" to get load balancing across the processes? > If the processes are to collaborate, and process packets in the same pipeline, they will need to share an event device (for example, a DSW instance). However, if you put each of your pipeline stages into a process with a single worker thread, you will not leave any room for an event device to load balance, since every eventdev queue will have only a single consumer linked to it.