From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <tedsxqian@gmail.com>
Received: from mail-wm0-f47.google.com (mail-wm0-f47.google.com [74.125.82.47])
 by dpdk.org (Postfix) with ESMTP id 512F78D8E
 for <users@dpdk.org>; Wed,  9 May 2018 04:57:58 +0200 (CEST)
Received: by mail-wm0-f47.google.com with SMTP id w194so21784393wmf.2
 for <users@dpdk.org>; Tue, 08 May 2018 19:57:58 -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=dyYw14V7KisxgOmmKZT1a8qirirARdnZ1YpG2vxzOEc=;
 b=QLQ8jDmDH6DpUsKFPkAMa3Nzjhof241FTAAiPOCglGdHh2KqRL2tkKmQJme3Ehdzq9
 5gfcUA2guIkEBQR0iDoffWGGuUZmsSahXRb6nFaapJabpX52zU+TJaWWVgWfiIjUN+Vn
 YoXTfMrfM2zL3/QwiNWzy/U3ZO6SW0O0vO9HhBsk7BtxPR9EnD6psNnBk0+vpdnHlYgE
 xjh44V+3aEuoiNHBGMKW0BF2RFAtChgsodenUoP+fgUwA0WKz1Q/L/YiDzpvyfITzbCt
 AUhneC5X16i35Kxiy1j1nonTn1MKOrGBOIHPCYBEHaXF2tqA15ZUsJZtYFn/7NRK8Y6q
 IG4g==
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=dyYw14V7KisxgOmmKZT1a8qirirARdnZ1YpG2vxzOEc=;
 b=Bux665O8XrdsEzCJQLhEl3LSeNcfm/XumBXzR8imvvxmnqotG6bJDIi4BZrrLElTFq
 /I73GbeUcEWWaV21cylcuDRs/1EUtL3nRLNbDZdQ9z0+lSAe6A6Z9wK+O5ibr3DQOL4R
 BaNQKOnnXwDBppr5F/5h6HjhtH3l/KNKrheKaN5TWL0r1XCGEkvpyHlwz8X0cmEEohCy
 28VxeCOvXLCeAVA9SntULj1Bzr4gJH+jQvEfzgfWFyXkjP2rwAiwftrjgibbZ4orVBLN
 GS7r0MtA+KPUIViZNYWjVC0ip7ArfvEI/gxQC8KNdAqCTpphH9otYiAWUvMMsQphizCh
 pQYQ==
X-Gm-Message-State: ALQs6tDoAbrN+FuonUOBrLH1Th3GC5z7tntStYuzvCn1UH/ixugkKnLz
 hynMv9nett7AQFELKrQ3lKz2bfbt9ignBDRYd1miRpc9
X-Google-Smtp-Source: AB8JxZq5vI86QMyUOcqFPUk6QzmN1jEwBJFPaElEc9c8V12RDUFe6sbKZQOXYKkvZ+Q6AY2zzk5BCHnvX1iu0Hk8l2o=
X-Received: by 2002:a50:b555:: with SMTP id
 z21-v6mr58254900edd.223.1525834677959; 
 Tue, 08 May 2018 19:57:57 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.80.140.33 with HTTP; Tue, 8 May 2018 19:57:57 -0700 (PDT)
From: shengxiao qian <tedsxqian@gmail.com>
Date: Wed, 9 May 2018 10:57:57 +0800
Message-ID: <CAPd3biCTS79T0mPgRM1jFUwqdPJQOqSGz3cKMkW+=V7gH4MQXg@mail.gmail.com>
To: users@dpdk.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Content-Filtered-By: Mailman/MimeDel 2.1.15
Subject: [dpdk-users] The latency of dpdk is more than 400us,
	something wrong?
X-BeenThere: users@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK usage discussions <users.dpdk.org>
List-Unsubscribe: <https://dpdk.org/ml/options/users>,
 <mailto:users-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/users/>
List-Post: <mailto:users@dpdk.org>
List-Help: <mailto:users-request@dpdk.org?subject=help>
List-Subscribe: <https://dpdk.org/ml/listinfo/users>,
 <mailto:users-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Wed, 09 May 2018 02:57:58 -0000

NIC: Intel 82599ES
DPDK version: 17.08.1


My test model is like this=EF=BC=9A
 Host A send request packet to host B=EF=BC=8Cwhen host B  receive the requ=
est
packet=EF=BC=8Chost B send replay packet to host A=E3=80=82Then host A send=
 next request to
host B ...

When the request packet size is less than or equal to  128 bytes, it works
fine. the round trip latency is less than 12us. But if the packet size is
more than 128 bytes=EF=BC=88even 129bytes),The latency is more than 400us=
=E3=80=82

I find that  most of the time consumed in the receiving package.

In my application, I call the rte_eth_tx_burst()  about every 1us.

What may be the cause? The NIC or dpdk driver receive packet made some
batch?