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 6E3AFA0540 for ; Wed, 6 Jul 2022 09:21:42 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id F08F040DF7; Wed, 6 Jul 2022 09:21:41 +0200 (CEST) Received: from mail-oa1-f42.google.com (mail-oa1-f42.google.com [209.85.160.42]) by mails.dpdk.org (Postfix) with ESMTP id 66B1840691 for ; Wed, 6 Jul 2022 09:21:40 +0200 (CEST) Received: by mail-oa1-f42.google.com with SMTP id 586e51a60fabf-10bf634bc50so11286937fac.3 for ; Wed, 06 Jul 2022 00:21:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=hDMrA4eD1GPMh4mM8R/rLOfw+0wQFKEqU1hLtyCcBQw=; b=Bg4vGiqS4g7IUZAf37acOVlv6ypCvJgQ0qx4zwTJqFHgytxJ8CIpSYF6GrHNlRUSIr nJy7Frx8T6dK+W91cBa9/DDAj+QtLDBTvaVz3iMaBdoOij9tYiKdSgOhQaGZjuReTQ7p Q5P6IewYzFonq4zX3fRLKTBXgJiqE/bkBX0y8NdB+GdSEO+JGwpyXAcztCZokjOxl+iX wyAiI+MOak+4zGimUrbH62w36DhJdjjm7kcTnYHyNey0Wm93YVE8p1FpzOZJUWYnAItP HnMW763WyYNlnNRyUZjVn7MUO7L1cj/R/lZGuYNmbJoBJsfec/m8bAMaCCSOCZExOVWE F0dA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=hDMrA4eD1GPMh4mM8R/rLOfw+0wQFKEqU1hLtyCcBQw=; b=hz9XqWFEhxiwBeQar/laFfuLMWrhug7S8xlh9A3nM0kmIC0TACBbvUe8E9Y1VZl0VC v8KPwefcliCVvNjf6siQeFFAAvGNvEZoMFLs6JZbhY/ZMdtMfWcGEVf65cVNJRWu66o2 2Ei2lghugsJ5VYkIMdC3UIBh8+c4ACDG11RSek18+jOZhLkBmwinyK3eFGtewD0Zbtbn TAchUE7NzM6GZQiHrtOGbs9cP/fMjO9UbLgSuzJwa+mIHnXJNF6xZbHiHpsIoD4Y0+c3 O1clHiClWK245sClc/DroU5c48wXkl/eAWk3tB7ab9vzJm/V0u/85MQzbvYu/r5eZ6Jp RrjA== X-Gm-Message-State: AJIora9Qr6vDTHh4c1re0R9np2u6jn3CzJSfi7YgNwy+xwjy6sXWq96/ PaLTipVzfPedogX0OAGUKTXDzVtYiY+cVNZGGQg= X-Google-Smtp-Source: AGRyM1v2ARR66yqDHNkoQL0nHItegaJDw643WSaAdDtx3Yta7eNn1nqXCbH2whG8iiKjQmnvP3uTeu0MniHLZ0UpAp4= X-Received: by 2002:a05:6871:820:b0:10c:20c:2bca with SMTP id q32-20020a056871082000b0010c020c2bcamr8132643oap.243.1657092099518; Wed, 06 Jul 2022 00:21:39 -0700 (PDT) MIME-Version: 1.0 References: <2ca6fffa-05df-9882-34e9-6c13dc2cc28f@hit.bme.hu> In-Reply-To: <2ca6fffa-05df-9882-34e9-6c13dc2cc28f@hit.bme.hu> From: Antonio Di Bacco Date: Wed, 6 Jul 2022 09:21:28 +0200 Message-ID: Subject: Re: rte_eth_tx_burst() always returns 0 in tight loop To: =?UTF-8?Q?G=C3=A1bor_LENCSE?= Cc: users@dpdk.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable 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 I wonder why calling eth_dev_tx_burst in a tight loop doesn't allow to write the packets into the transmit buffer. Only solution I found is to include a small delay after the tx_burst that is less than the estimated serialization time of the packet in order to be able to saturate the ethernet line. Anyway I wonder if this is the right approach. Thx, Antonio. On Sun, Jul 3, 2022 at 10:19 PM G=C3=A1bor LENCSE wrote= : > > Dear Antonio, > > According to my experience, the rte_eth_tx_burst() function reports the > packets as "sent" (by a non-zero return value), when they are still in > the transmit buffer. > > (If you are interested in the details, you can see them in Section 3.6.5 > of this paper: http://www.hit.bme.hu/~lencse/publications/e104-b_2_128.pd= f ) > > Therefore, I think that the return value of 0 may mean that > rte_eth_tx_burst() can't even commit itself for the future delivery of > the packets. I could only guess why. E.g. all its resources have been > exhausted. > > Best regards, > > G=C3=A1bor > > > 7/3/2022 5:57 PM keltez=C3=A9ssel, Antonio Di Bacco =C3=ADrta: > > I'm trying to send packets continuously in a tight loop with a burst > > size of 8 and packets are 9600 bytes long. > > If I don't insert a delay after the rte_eth_tx_burst it always returns = 0. > > > > What's the explanation of this behaviour ? > > > > Best regards, > > Antonio. >