From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f176.google.com (mail-io0-f176.google.com [209.85.223.176]) by dpdk.org (Postfix) with ESMTP id 307C4C36A for ; Fri, 20 May 2016 23:47:25 +0200 (CEST) Received: by mail-io0-f176.google.com with SMTP id p64so68824002ioi.2 for ; Fri, 20 May 2016 14:47:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc; bh=vAtCxFcB/qFQWKH4Kjh05S0+7Ip3s5LKNZlVynO6TaA=; b=lTTzUYexCI7u7ey7YBMnab7SLbf+cs204bZ8KKOQsUlv9qxtu5GwcVC8j9iydaUZyF P8FxvQ4vlpTXfc/3XMi1hwA6h4sQFUyYyF76yiT5G6FuEyXL37tBEDtFDr8yA0/U9NKY 9sjl8I8rjPY0EgZ3Q1jgc/el862Yy4mMckSj6fu3xbuAMfcZxrpymsSTkAhRFSvKc8E2 Bt3sH7JuHVX2MDetRHIYVyAGMT9ZAZJt5dgB7rWZHHV68oZDjVsRH+RWhNTTS/w0odgs A5mxFcAUgvVp5EPhnDzZSQAqDBW4AIxmtWoahlWv5mPKxYOc3TsMNGbGfjXi5f+3iJsw aEQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc; bh=vAtCxFcB/qFQWKH4Kjh05S0+7Ip3s5LKNZlVynO6TaA=; b=X/oHc8RCBO1xqFjiEhY3gxLztZ8tD9WHTxrVyP40a7Qpuv0UOkpZQh7X0vj8GAbcOX c1KslPwV2sg051qkF0U1Tcw/Qru123nj4BEJulcsN+RZfYOPRxDQS4h6IJ1Le+G8FY68 MKDI/jCrnUrQRCWLzsoUfMsjG+Y2/8mPRmKW/ugU+G6fwzztCCL4dxPN403P1wGSjg08 AuarJmWs1yLZR8MFHdbhZ7/MnNErar8FtKmGZoanREBTfocOeyR5tCyf0M680Bj9JD/x sWmnKyRR2Yp0DjEvP3b61i6SvLw6z3wIOs8mdw0vKKoDCPz970LIMu7XfF4rXBBPKPcT Ks7A== X-Gm-Message-State: AOPr4FUuS5AQ53XhnTZ7NIJ4fhchXKm7Upn7ofUMKwVgIKT1aj0WspUhJggRSti2Dbj6CBq5nKtPDkBIVvtiEg== MIME-Version: 1.0 X-Received: by 10.36.103.19 with SMTP id u19mr4599551itc.8.1463780844625; Fri, 20 May 2016 14:47:24 -0700 (PDT) Received: by 10.107.142.211 with HTTP; Fri, 20 May 2016 14:47:24 -0700 (PDT) In-Reply-To: References: Date: Fri, 20 May 2016 14:47:24 -0700 Message-ID: From: SwamZ To: Alexander Duyck Cc: dev@dpdk.org Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] Rx_missed_errors drops with larger packet size X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 May 2016 21:47:25 -0000 Hi Alex and Bruce, Thanks for the reply. Alex, Just saw your email. You are right, this issue was happening for multicast packets only. On 82599 NIC, multicast and broadcast packet replication (IXGBE_VT_CTL_REPLEN) was enabled even for single VF case, hence NIC was dropping the packets as rx_missed_errors. After disabling the replication, we are not seeing any drops. Regards, Swamy SRK On Fri, May 20, 2016 at 9:45 AM, Alexander Duyck wrote: > On Fri, May 20, 2016 at 2:09 AM, SwamZ wrote: > > Hi, > > > > > > While doing performance testing with larger packet size (like 4000 > bytes), > > we are seeing rx_missed_errors on the interface. This issue is not seen > > with packet size less than 2000. There were questions asked in this forum > > on rx_missed_error, but there was not any conclusion. Please let me know > > what could be the reason for these drops. > > > > > > I tried the following without any luck: > > > > 1) Tried different burst size like 16, 32 an 64 > > > > 2) Tried different number of the rx descriptors like 512, 1024, 2048 and > > 4096. > > I've seen issues like this occur on the 82599 using the Linux kernel > diver in the past, but it was usually related to CPU C states. I'm > assuming that shouldn't apply since you are using the poll mode driver > right so there are no interrupts and the CPUs are busy polling. > Another thing to check is that you have sufficient PCIe bandwidth. > Take a look at an lspci -vvv for the device and make certain it is > connected at x8 Gen2. > > > Setup and testing details: > > > > CPU Speed : 2.6 GHz > > > > NIC : 82599ES 10-Gigabit > > > > IO Virtualization: SR-IOV > > > > IO and packet processing cores are in the same NUMA. > > If you are running SR-IOV then the SRRCTL_DROP_EN bit should be set in > all the SRRCTL registers if I am not mistaken. As such if you are > triggering Rx missed errors it may not be related to the driver > directly but could point to some sort of PCIe but utilization issue. > How many VFs are you using and is any of this traffic multicast or > broadcast? Multicast or broadcast traffic can potentially saturate > the PCIe bus if there is enough of it on the wire as each packet is > normally replicated for each active VF. So 1 packet on the wire (4K) > can become 8 on the PCIe bus (32K) if you have 7 active VFs. > > > Packet size : 4000 bytes > > > > Traffic rate: 80 % line rate. If the traffic rate is < ~80% then drops > are > > not seen. > > > > Application: This is a sample application developed using L3fwd example > app. > > > > DPDK version: 1.7 > > Thanks, > > Swamy > -- Swamz