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 4184EA0541 for ; Fri, 7 Feb 2020 10:19:27 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 8DA681C06A; Fri, 7 Feb 2020 10:19:26 +0100 (CET) Received: from mail-ua1-f52.google.com (mail-ua1-f52.google.com [209.85.222.52]) by dpdk.org (Postfix) with ESMTP id DDC261C068 for ; Fri, 7 Feb 2020 10:19:24 +0100 (CET) Received: by mail-ua1-f52.google.com with SMTP id 59so621910uap.12 for ; Fri, 07 Feb 2020 01:19:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=ZfPe8lwO2Wz3LJXRTrmZwHlIbpbfMKnt+ehzuGwQF6M=; b=RwSD+w/T2o/rNeRBGogYqQHqovq+bQu0x2h2qfUZpai3rVvz9fj3OQlBB7x5vgRSZX iACS50KFAZYEM/AxxBkAyEodwO3nJIsG29VovB37T9PM35mSd6AvXIQZArM7EvY4lDpz RqyNGnD8DMUiHBdKqT/X8u3TOzcT3FnDSInsR56PJg5K0T27D1pLbwlEjE9huva7DuHL 30Or+Te7SSnumJmgLgj3EUh1ccmzihliWzBz7WnE5MFowRj4Xy7rPRBYfeSPO3wCPskz GA/INUCcLEDblBxGCLWf4NbpcXZlnK0WGLJluz7ijN92/fTBkxUpBDdleHNyxCoQvtAp hgtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=ZfPe8lwO2Wz3LJXRTrmZwHlIbpbfMKnt+ehzuGwQF6M=; b=iQZuIX/DkFTkO+BQU0tprUaVT8QgIfQ9B5uH/fBjBd2bEdHjKkf+H3GIhtPy+Oy8Ck qBW4MYAvwsHWh1h4g0dgI8GcJc0QL6tGaW4qexprHJWcXYmRbKiCjql8lU/4Pk/h8vVv dBBA8QrX9tlI8SovVrv2JJ6NW/9QAWJ16ZzgWNcaagF1ignOSWVhIarjoESt8nUBl4to oDWR14i0KKntvUkT7yVNudXw0l42g4YYxcnxXzC+k3bKy4jhL/vPQiujFo0tLXPNAqDS 2/3xLLvXxNdLr0p4xPMIdguVwoGTwCsD1np+4gYnLJCIPRYMthXanNA4TMcdCzxvVKmW QcdA== X-Gm-Message-State: APjAAAWSu5GAoNV9HqJnp9lrwmH63xQHeHGU6zpqm/JniezXbi6U3r4q 3Ti+Dfnl9kNZu/mk3MfA6TqTF1uRe1XxmQxUBuocCmjK X-Google-Smtp-Source: APXvYqwsrLki8TU/dW1QYziPUqAbgLVhHadS6GzdmEFSwaFDbsuUDAAWWXbMK1FeQSoZOmH/PO8MKRunWRRFQhUB0wM= X-Received: by 2002:ab0:555e:: with SMTP id u30mr4212002uaa.39.1581067163982; Fri, 07 Feb 2020 01:19:23 -0800 (PST) MIME-Version: 1.0 From: Victor Huertas Date: Fri, 7 Feb 2020 10:19:13 +0100 Message-ID: To: users@dpdk.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: [dpdk-users] high latency detected in IP pipeline example X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org Sender: "users" 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 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 ip pipeline capability of arbitrarily assigning the 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