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 75FDDA00C5 for ; Thu, 14 Jul 2022 13:40:06 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 102B542B73; Thu, 14 Jul 2022 13:40:06 +0200 (CEST) Received: from mail-ed1-f46.google.com (mail-ed1-f46.google.com [209.85.208.46]) by mails.dpdk.org (Postfix) with ESMTP id 6746F42B6D for ; Thu, 14 Jul 2022 13:40:05 +0200 (CEST) Received: by mail-ed1-f46.google.com with SMTP id r18so2008311edb.9 for ; Thu, 14 Jul 2022 04:40:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=emumba-com.20210112.gappssmtp.com; s=20210112; h=mime-version:from:date:message-id:subject:to:cc; bh=1ZADeobu1WFfTAlvNNm0soPZKmo+TYVOxyNp3r41v/Y=; b=pZagZuQAX01+QWpSuYlIlH/eOv+klNBSu4Uz1R/nUdlwxAdcCHC38VgxmnkZT9k9Bu 0FBJsEkjuq8LvsMFfRser85+PXljugrkqjrzwupyZfMN8R6qfMKrboSe2F5XZt8AVjYt d9k2cl0WYQfSo62lc6lT45oL3fN+clV/PtahfKXMpqHyrvl8E9F/2iMI6JgulKllTUmH oHy1UsW5sn2NYtpM4Xgf42ENQyNx7yOXPWLNQ2OBWcCtZzyJIvwBP6dQ5RXNcEhYwJ77 8KQCSW+81HqLStrb2v6GGZVWs2Ty/mNj+YOYKlXeQuh1Sf1XevWtLnedgGXv155ifjv4 350Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=1ZADeobu1WFfTAlvNNm0soPZKmo+TYVOxyNp3r41v/Y=; b=1HsLpWJaYKq2ZIct8nPgklVoQ7Hg9S+FiM60fKklkzzLoWQDURx4x9dxvLg12a2/Gj 4mTGWC4nz3/0rUqbZ37rdNERZn6ngqoIer1zVoDQ8Ny4Cd98FBeu2mhJh5GoAUvBFjWF Wc81jzYS9Uo/SHf3WBiipDg42kq2reulc+22fLLkCLpm65UUbuwDxSbe8woc1AUbS+4X ix4YS721CoAp0VewtzTRTSC6QwAvw1Jl027mcfp0CDrO/kpp3E5Iyw+MAjm+/j61fV8G f1YwENW21xO1NVFqRT649Wtkm+CXAH4yBziinYpxtRhFUxH9yib1aYP0UY4GdsvtQhy6 6ktA== X-Gm-Message-State: AJIora+b0vEdNaAbUDUSPmWZ596bKDTmCbfMPChQ+VknUJFbHb8+6X9G cco8zuhC7O3VvVpFo9q7gADlSh1T54A/mU1IeRMuppZQtlwbNmMV X-Google-Smtp-Source: AGRyM1uU4afmwqIoKc3oea5xDSdCzJmB+c3vq0HxaDjnRbQU4/6kd+y4bpp3MF4sidzViZOiTlIoNp7mroh80J1SKns= X-Received: by 2002:a05:6402:1389:b0:43a:ceea:93fd with SMTP id b9-20020a056402138900b0043aceea93fdmr11922475edv.64.1657798804923; Thu, 14 Jul 2022 04:40:04 -0700 (PDT) MIME-Version: 1.0 From: Usman Tanveer Date: Thu, 14 Jul 2022 16:39:54 +0500 Message-ID: Subject: Packet Accumulation in RX and TX in bnx2x To: users@dpdk.org Cc: shshaikh@marvell.com, rmody@marvell.com Content-Type: multipart/alternative; boundary="000000000000e0776f05e3c25ce2" 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 --000000000000e0776f05e3c25ce2 Content-Type: text/plain; charset="UTF-8" Hi, I have a *BroadCom NetXtreme II BCM57810 10 Gigabit *with a *bnx2x* driver. I was trying to measure the performance of the network card. I'm running DPDK-L2FWD application to receive and send packets with MAX_PKT_BURST = 1. but I noticed that packets are being accumulated somewhere in bnx2x_rxtx. There is some sort of batching/buffering happening in rxtx. So, the latency of the packets is increasing as they have to wait. The first packet of the batch is received with the minimum latency and incoming packets are received with the accumulated latency of the previous packets. After a specific number of packets (6-7 packets), the same pattern repeats i.e. a packet arrives with the minimum latency and incoming packets with accumulated latency until the specific number of packets arrives. I've copied the latency measured for some contiguous packets. I tried to explore bnx2x_recv_pkts() and bnx2x_xmit_pkts() in bnx2x_rxtx.c, but didn't get any clue why the packets were being accumulated. Sequence Latency (microseconds) 4825105 9.37207 4825106 10.72168 4825107 15.06543 4825108 19.394043 4825109 22.665039 4825110 26.979004 4825111 8.74707 4825112 11.145996 4825113 14.439941 4825114 18.701172 4825115 23.082031 4825116 27.402832 4825117 9.164062 4825118 11.623047 4825119 15.944824 4825120 19.066406 4825121 23.589355 4825122 27.909668 4825123 9.701172 4825124 11.13916 4825125 15.489746 4825126 19.780762 4825127 23.111816 4825128 27.403809 --000000000000e0776f05e3c25ce2 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi,

I have a BroadCom NetXtreme II B= CM57810 10 Gigabit with a bnx2x driver. I was trying to measure = the=C2=A0performance of the network card. I'm running DPDK-L2FWD applic= ation to=C2=A0receive and send packets with MAX_PKT_BURST =3D 1.=C2=A0
but I noticed that packets are being accumulated somewhere in bnx2x_r= xtx. There is some sort of batching/buffering happening in rxtx. So, the la= tency of the packets is increasing as they have to wait.
The firs= t packet of the batch is received with the minimum latency and incoming pac= kets are received with the accumulated latency of the previous packets. Aft= er a specific number of packets (6-7 packets), the same pattern repeats i.e= . a packet arrives with the minimum latency and incoming packets with accum= ulated latency until the specific number of packets arrives. I've copie= d the latency measured for some contiguous packets.

I tried to explore bnx2x_recv_pkts() and bnx2x_xmit_pkts() in bnx2x_rxtx.= c, but didn't get any clue why the packets were being accumulated.=C2= =A0

=09 =09 =09
Sequence L= atency (microseconds)
4825105 9.= 37207
4825106 10= .72168
4825107 15= .06543
4825108 19= .394043
4825109 22= .665039
4825110 26= .979004
4825111 8.= 74707
4825112 11= .145996
4825113 14= .439941
4825114 18= .701172
4825115 23= .082031
4825116 27= .402832
4825117 9.= 164062
4825118 11= .623047
4825119 15= .944824
4825120 19= .066406
4825121 23= .589355
4825122 27= .909668
4825123 9.= 701172
4825124 11= .13916
4825125 15= .489746
4825126 19= .780762
4825127 23= .111816
4825128 27= .403809

--000000000000e0776f05e3c25ce2--