From owner-freebsd-net@FreeBSD.ORG Mon Oct 3 10:21:57 2011 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B4B4B106566B for ; Mon, 3 Oct 2011 10:21:57 +0000 (UTC) (envelope-from sodynet1@gmail.com) Received: from mail-iy0-f182.google.com (mail-iy0-f182.google.com [209.85.210.182]) by mx1.freebsd.org (Postfix) with ESMTP id 7D1568FC0C for ; Mon, 3 Oct 2011 10:21:57 +0000 (UTC) Received: by iadk27 with SMTP id k27so7099941iad.13 for ; Mon, 03 Oct 2011 03:21:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=QnIo/fiDnWBDX9WquGafmUJWhSRkkbSB0lhT+0Rgojw=; b=q21+4HksjBm/sVR/Ht3hW9x10sqvLv1slnmgAjBCkeyAM3ZwhCLi6GTuwqlAmYomu8 sPOP0DLaZ8WiPM1ylG1G+e30L2zT6Xf9Km3GOfqh/N99/WCs2AnSfwq805KWVrqTYWNJ Y83hLurYiCAE+SKO74WfhKzZ9TcX00dO6r/eQ= MIME-Version: 1.0 Received: by 10.231.46.66 with SMTP id i2mr9956956ibf.0.1317637316813; Mon, 03 Oct 2011 03:21:56 -0700 (PDT) Received: by 10.231.12.138 with HTTP; Mon, 3 Oct 2011 03:21:56 -0700 (PDT) In-Reply-To: References: <4E886A3B.7000502@sepehrs.com> <4E896999.3020001@sepehrs.com> Date: Mon, 3 Oct 2011 13:21:56 +0300 Message-ID: From: Sami Halabi To: Jack Vogel Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: "freebsd-net@freebsd.org" , Hooman Fazaeli Subject: Re: em(4) high latency w/o msix X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Oct 2011 10:21:57 -0000 Hi, Sorry for the questuion. what are the benefits of MSIX ? i don't have on my FREEBSD 8.1-R a sysctl hw.em.msix ... i have em card 82751EB. is msix NIX related? Thanks in advance, Sami On Mon, Oct 3, 2011 at 11:20 AM, Jack Vogel wrote: > Can you try the driver in 8.2 and possibly stable/8 to see the behavior > there. > > And, just curious, why are you disabling MSIX? > > Jack > > > On Mon, Oct 3, 2011 at 12:51 AM, Hooman Fazaeli > wrote: > > > ** > > Hi Jack > > > > The hardware is a PCIe network appliance with 3 port modules. The ports I > > have > > used in the test are 82574L residing on a 4 port module. Anyway, as I > noted > > in last mail, the stock 7.3-RELEASE driver does not expose this problem > on > > the same hardware. > > > > > > On 10/2/2011 7:38 PM, Jack Vogel wrote: > > > > On what hardware? > > > > Jack > > > > > > On Sun, Oct 2, 2011 at 6:42 AM, Hooman Fazaeli >wrote: > > > >> > >> Latest em(4) driver from HEAD seems to have high latency > >> when MSIX is disabled. > >> > >> With MSIX enabled (hw.em.enable_msix=1): > >> > >> # ping -c5 192.168.1.83 > >> PING 192.168.1.83 (192.168.1.83): 56 data bytes > >> 64 bytes from 192.168.1.83: icmp_seq=0 ttl=64 time=0.055 ms > >> 64 bytes from 192.168.1.83: icmp_seq=1 ttl=64 time=0.076 ms > >> 64 bytes from 192.168.1.83: icmp_seq=2 ttl=64 time=0.066 ms > >> 64 bytes from 192.168.1.83: icmp_seq=3 ttl=64 time=0.051 ms > >> 64 bytes from 192.168.1.83: icmp_seq=4 ttl=64 time=0.063 ms > >> > >> --- 192.168.1.83 ping statistics --- > >> 5 packets transmitted, 5 packets received, 0.0% packet loss > >> round-trip min/avg/max/stddev = 0.051/0.062/0.076/0.009 ms > >> > >> With MSIX disabled: > >> > >> # ping -c5 192.168.1.83 > >> PING 192.168.1.83 (192.168.1.83): 56 data bytes > >> 64 bytes from 192.168.1.83: icmp_seq=0 ttl=64 time=0.180 ms > >> 64 bytes from 192.168.1.83: icmp_seq=1 ttl=64 time=0.164 ms > >> 64 bytes from 192.168.1.83: icmp_seq=2 ttl=64 time=0.169 ms > >> 64 bytes from 192.168.1.83: icmp_seq=3 ttl=64 time=0.172 ms > >> 64 bytes from 192.168.1.83: icmp_seq=4 ttl=64 time=0.167 ms > >> > >> --- 192.168.1.83 ping statistics --- > >> 5 packets transmitted, 5 packets received, 0.0% packet loss > >> round-trip min/avg/max/stddev = 0.164/0.170/0.180/0.005 ms > >> > >> As you see, w/o MSIX, RTT increases by a factor of 3. > >> > >> I also tested the following drivers: > >> - igb(4) from HEAD: OK. > >> - Stock 7.3-RELEASE: OK. > >> - Stock 7.4-RELEASE: problem exist. > >> > >> Any ideas? > >> > >> > >> > >> > >> > > > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" > -- Sami Halabi Information Systems Engineer NMS Projects Expert