From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 15D76A034F for ; Mon, 29 Mar 2021 09:39:18 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id D184740151; Mon, 29 Mar 2021 09:39:17 +0200 (CEST) Received: from mail-lf1-f50.google.com (mail-lf1-f50.google.com [209.85.167.50]) by mails.dpdk.org (Postfix) with ESMTP id 3E73440042 for ; Mon, 29 Mar 2021 09:39:16 +0200 (CEST) Received: by mail-lf1-f50.google.com with SMTP id o126so17048927lfa.0 for ; Mon, 29 Mar 2021 00:39:16 -0700 (PDT) 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=zPDJsMmjRLvqmeQ7/WJriD/XmjlUOjfzPZZbzizsBiU=; b=YcCXDoQIMjh92lxiwEX2wuGAOfmr91SaZn3//9iWKv1pJFBP49R3lAw4a+IIaiz/iG KCSYwlpw2II6m797cZ3taOKYtwe1bt4ZdAami5ZJbcLrEkKSj2b5gF3pCMxv+Ce/CczK /orK3hSQWx9FKpLijyAxecQjKQTolaCOd/NwfOb7ny/pVUKrOBciRfqnKl3/r+rq3LwL kW9b789SSfo5A/vMfVUnkA85YpN2dYL3jirL8jyvrT05//Aec9okcDbzdrvozv2Qz4qO TGc65Mv6rgSD9rHjqfT1qEhq/vxzoCQ01HEztBtW4XvEUeXQIzWloRRUtMF5Gmt9TD9Q mYsA== 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=zPDJsMmjRLvqmeQ7/WJriD/XmjlUOjfzPZZbzizsBiU=; b=FbsYlHN4jQlTU9iJDZT+JrECgCOBbgUDd0dR7ByFD2MW9YCGNO/M6tWbzXbVwcDSP6 mA6YZq6/0ZnXLpqyYWfmhnnVmNbSnybnRYysASmqdPHSqByEVR/XEqJc1rpgsOs4ncA9 vPwZ28QZo42nLFb7l7d/HjFecklZOAEXiGuKjDqjvvUx/DRKiCS5pjwoQ44Q9IucQssr 7rMX8KrUVBXbJtcsRtH4M6NVzWPLoKqq/XnBtGkP8YlMmQcDYSGLw4c45ghTRKBmdfyB CFnwPz1zkaGL6yueAKvV9d8t/b3XkeupGpZ2y3vx1Oki36Z2AgXKAmSBpsSV+Az1tnSn akOg== X-Gm-Message-State: AOAM5322Rx1cKNwnBh1djIQzh9Dbsh64BF6Rv0DFUnBN5csYsTGNnmOZ ptJPSLRBg5ktlZRp8juqCRN3Bvh7jcZo4wGXSco+7u8U0VwcaA== X-Google-Smtp-Source: ABdhPJynj6e8EZmulLun+9JEy7mROlKF4XcRL9/wUNiUWC1z59j+uWdYQ8GFX7FXdWHm5dL8Fgezu/ij77jK+Qm4aaw= X-Received: by 2002:a19:c54:: with SMTP id 81mr15077780lfm.401.1617003555585; Mon, 29 Mar 2021 00:39:15 -0700 (PDT) MIME-Version: 1.0 From: Kaustubh Mendki Date: Mon, 29 Mar 2021 13:09:04 +0530 Message-ID: To: users@dpdk.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 Subject: [dpdk-users] Packet drop observed due to increased processing time of rte_eth_tx_burst( ) after dpdk upgrade X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.29 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, Our app is currently using dpdk 17.11.10 (CentOS 7.9 Mellanox OFED 5.2-2.2.0.0-rhel7.9-x86_64). It is quite similar to test-pipeline example with io_rx, workers and io_tx threads running on separate lcores. After upgrading to either dpdk 19.11.2 or dpdk 20.11.1, we observed few packets being dropped between workers and tx threads because tx thread is not able to keep up with the rate at which worker threads are enqueuing packets in the ring, and eventually ring becomes full. it occurs only for a moment initially at the start of traffic generation (@500 Mbps), then packet drops are not seen thereafter. The bottleneck seems to be rte_eth_tx_burst() call in tx thread which seems to be much slower in dpdk 19.11 and 20.11 consuming ~150 milliseconds initially for few packets and later improving with processing time in nanoseconds. With dpdk 17.11.10, where no drop is seen, the same call executes in ~50 microseconds for initial few packets and later in nanoseconds. The burst size used in transmission is 1. Is there any change in the implementation or configuration (offloads?) required for rte_eth_tx_burst() in dpdk 19.11.2 which could impact the initial performance? With only dpdk upgrade and all other platform specific things (OS, drivers) being the same, I am not sure what could be the reason behind the higher execution time for the burst API in dpdk 19/20? Thanks, Kaustubh