From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 579B5A0553; Mon, 17 Feb 2020 17:41:16 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id A91851D9C1; Mon, 17 Feb 2020 17:41:15 +0100 (CET) Received: from mail-vs1-f52.google.com (mail-vs1-f52.google.com [209.85.217.52]) by dpdk.org (Postfix) with ESMTP id D2FC61C037 for ; Mon, 17 Feb 2020 17:41:13 +0100 (CET) Received: by mail-vs1-f52.google.com with SMTP id x18so11107151vsq.4 for ; Mon, 17 Feb 2020 08:41:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=/o/lI27ZXaGRH34uro34WWbXOSMk+18Qp8ipvvxV9AM=; b=BXl+5DzjrVRJvYk5slmU9Uan7MFcIYxtEeOIZO4nCGf/MXqyX07v+ird1PE3XnWLjq 9n9HSRz5USPFWftjd46T0K67qbexydNkRX4FVnb1D0QmTvJmwBQxousltZWAaE7HPhwg npdFQStD+T/We9n9hNC8rAU32le7yCoGPCw+sumcm9IHLcSMLtT/gOc6m9n+EjfwZCF/ TMU85bT7WxIDwz3pJtdXjmyX6WrMlzSgYfjXCch8I0p9BjzB3py2OSlVIbeleJUR9Kyh WKI1yY2BJCZmiKW3xuiCcON1BFLYKHrvFGmy+xHbVa9JEw0r/d4cL6hjpYEHOm+5yhYQ olLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=/o/lI27ZXaGRH34uro34WWbXOSMk+18Qp8ipvvxV9AM=; b=dhySNYzG6dbBVVfox2h23CBTuL5z+LNzDSqJSfRquZ8DNn6tcNMKpuATAyQhZPLewk 2TvHKgTSIeNkGUK72E1V1TkCxQE4dC1PNFgPejQpSf5SPLklZRnOS/IyOFI0SQ7o1cP8 GIvv+TDs/ChAARsannGwyJPXhNGuk4UL2og4c006RWMQc15YlpFNBN1b4aY6drtSnfp1 mgUChf5cExV/it6k65GkoiqBiNYfhw4BZjnwnh+FXAYZ1wAxyfL1t/NIvCwgqpCAuhBG bq1RsmYOqyytzgQpRkRYGdb+Llqm/TZBd3WznL+9PyULYcfCDz6HkRjh0hOXHRS5Kjsq egOg== X-Gm-Message-State: APjAAAUZj7zbjUAyPZWu23lv7eFRuYG9bmwvn5ekec7oKy2542geAa4k y5AutPacFRMjerVtRi1F4+Rosx5XoVhrtWbQiFxI9Q== X-Google-Smtp-Source: APXvYqyo8JRaSOP6QRpckTjDaVf40IzsFewu8kt0PQueWP7MhkVhU1YoT6rQeGTnHIOE2pGCH74BqdDXuMutrjl3oy4= X-Received: by 2002:a67:8704:: with SMTP id j4mr8952249vsd.106.1581957673065; Mon, 17 Feb 2020 08:41:13 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Victor Huertas Date: Mon, 17 Feb 2020 17:41:01 +0100 Message-ID: To: dev@dpdk.org Cc: cristian.dumitrescu@intel.com Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: [dpdk-dev] Fwd: high latency detected in IP pipeline example X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi all, I am developing my own DPDK application basing it in the dpdk-stable ip_pipeline example. At this moment I am using the 17.11 LTS version of DPDK and I amb observing some extrange behaviour. Maybe it is an old issue that can be solved quickly so I would appreciate it if some expert can shade a light on this. The ip_pipeline example allows you to develop Pipelines that perform specific packet processing functions (ROUTING, FLOW_CLASSIFYING, etc...). The thing is that I am extending some of this pipelines with my own. However I want to take advantage of the built-in ip_pipeline capability of arbitrarily assigning the logical core where the pipeline (f_run() function) must be executed so that i can adapt the packet processing power to the amount of the number of cores available. Taking this into account I have observed something strange. I show you this simple example below. Case 1: [PIPELINE 0 MASTER core =0] [PIPELINE 1 core=1] --- SWQ1--->[PIPELINE 2 core=2] -----SWQ2----> [PIPELINE 3 core=3] Case 2: [PIPELINE 0 MASTER core =0] [PIPELINE 1 core=1] --- SWQ1--->[PIPELINE 2 core=1] -----SWQ2----> [PIPELINE 3 core=1] I send a ping between two hosts connected at both sides of the pipeline model which allows these pings to cross all the pipelines (from 1 to 3). What I observe in Case 1 (each pipeline has its own thread in different core) is that the reported RTT is less than 1 ms, whereas in Case 2 (all pipelines except MASTER are run in the same thread) is 20 ms. Furthermore, in Case 2, if I increase a lot (hundreds of Mbps) the packet rate this RTT decreases to 3 or 4 ms. Has somebody observed this behaviour in the past? Can it be solved somehow? Thanks a lot for your attention -- Victor -- Victor