From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id A3FFDA0679 for ; Thu, 4 Apr 2019 17:41:17 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 22D171B419; Thu, 4 Apr 2019 17:41:16 +0200 (CEST) Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) by dpdk.org (Postfix) with ESMTP id BE1761B3FB for ; Thu, 4 Apr 2019 17:41:14 +0200 (CEST) Received: by mail-pl1-f181.google.com with SMTP id y6so1346996pll.13 for ; Thu, 04 Apr 2019 08:41:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=RBf1NBFQ4Coo/qVxSe88dxqHQAPozILZe1ZLzGkL4/I=; b=jCRetHQeCI9jpDX6dUWTLEhv9pQUWAqmHoh0ngrEwqKMjRhQXc7mBeejk9f2mPr4t/ uSlnjLBDspzePsxGTttmlguzwLbpOmN9OPIGmaJdCCjXbfjTUPar6r62hjNk5M1SO5GI C9LhR2L6a+4yW9HEAkn+wVEofoejTwIstxYVwafR4LrS8qHoIcD+ao6KfmvmUKVsXxx7 1pjBx7zv+zgpKGRJdRjG/lJH+mlDXVvSpedwo74KP8Hxf4bJpR7RqA3RtAbLSNbb1Ry/ CJ1+MjkdyhhqYTRxl7rKwL08gV4Pz8E78qg/vukWuTRPh7Cq9LPVf3LBn03Odu/yA4fw eBeg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=RBf1NBFQ4Coo/qVxSe88dxqHQAPozILZe1ZLzGkL4/I=; b=UklWJLnxG1HB+dKvyhW6JzADHOhvo9q4XwtS5fdUz5AINDSwveUz1LNB69O+q2Deuo IajFHXec1x7Pl1Voo3ryg6UclC+nrmkT96cCgOuUtSRj7/9LOnvqK9pqClp772TxWNG2 GLpc5C+1V5M3ESVazcOpZZqvzMhn1olOx7u8GawyvFE3rXmasP6Knsyq+z1020Httfvb OjSTnUW/kHADY4Qpxt/y5erYgmp0f+vFsMg+L4IS9xyPwKyTUB0TByVaO5dOvpxLW+IH OWU0n0ap/ehHSkPOBh4HCqzNSM0qQO9HRAYezt30lGWCD1DY1G/ZC6DJdG6m6Z4m3RnD US3A== X-Gm-Message-State: APjAAAWCdXkwvK8Tta0KEm7jxcf3g3oV7B58Bs7AWkSYB4i5itBy9Zw8 k+4khJcCA1yJTYfaF9yvX4Udqw== X-Google-Smtp-Source: APXvYqyeEPN++/UMegU63oqruZZro1nfBRlu4fejR+jKdol0M422kVqGuelsuH3y9z9uMlTTP3zCrQ== X-Received: by 2002:a17:902:2de4:: with SMTP id p91mr6949682plb.191.1554392473511; Thu, 04 Apr 2019 08:41:13 -0700 (PDT) Received: from shemminger-XPS-13-9360 ([167.220.59.121]) by smtp.gmail.com with ESMTPSA id y12sm56668502pgq.64.2019.04.04.08.41.12 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 04 Apr 2019 08:41:13 -0700 (PDT) Date: Thu, 4 Apr 2019 08:41:10 -0700 From: Stephen Hemminger To: Sharon Cc: users@dpdk.org Message-ID: <20190404084110.76def58a@shemminger-XPS-13-9360> In-Reply-To: <8cf0736f-29d8-1ce7-ea77-83f091cd666f@altencalsoftlabs.com> References: <9beaa13f-239a-5361-81ea-20d5237bf1be@altencalsoftlabs.com> <8cf0736f-29d8-1ce7-ea77-83f091cd666f@altencalsoftlabs.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-users] Tx burst getting failed with Virtio driver 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" On Thu, 4 Apr 2019 13:01:16 +0530 Sharon wrote: > Hi, > > With a dpdk based application inside GCP VM instance, > it is observed that while sending UDP packets of length 1300 at around 6 > Gbps rate, tx burst starts failing frequently. Virtio (like all devices) can only transmit so fast. If you transmit faster than the host can consume, the queue will get full this shows up in DPDK when all transmit descriptors are used. 6Gbps is about 4.4 Mpps and the upper bound on virtio is usually about 1 to 2 Mpps because of the overhead of host processing (vhost and linux bridge).