From owner-freebsd-net@FreeBSD.ORG Mon Oct 3 00:50:11 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 BE207106564A for ; Mon, 3 Oct 2011 00:50:11 +0000 (UTC) (envelope-from jfvogel@gmail.com) Received: from mail-wy0-f182.google.com (mail-wy0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id 482DF8FC15 for ; Mon, 3 Oct 2011 00:50:10 +0000 (UTC) Received: by wyj26 with SMTP id 26so3578586wyj.13 for ; Sun, 02 Oct 2011 17:50:10 -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=1VuE5twOx4AIqh4Us8JHb0IZWs5a88wj6jlt1zAT5Yw=; b=RlBnRBsLDCvj0Kf93zYYMljC7sOccyq8f/FolNpwlsXa7qS9jnW7i973yAvAnS8itd y5hzqGDwppdiCEgSn3lE2scVKgDdWOefg6sJe13CwaMqKgbLIX+ZTia+Z/iuQ5HXi9cH 3I3ucRejrLUDUuIEzChCb7Mmi3a7zJ3rLDslQ= MIME-Version: 1.0 Received: by 10.227.13.84 with SMTP id b20mr2341161wba.13.1317603010034; Sun, 02 Oct 2011 17:50:10 -0700 (PDT) Received: by 10.180.106.35 with HTTP; Sun, 2 Oct 2011 17:50:10 -0700 (PDT) In-Reply-To: References: <4E886A3B.7000502@sepehrs.com> Date: Sun, 2 Oct 2011 17:50:10 -0700 Message-ID: From: Jack Vogel To: Arnaud Lacombe 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 00:50:11 -0000 There are differences between adapter and LOM, furthermore, someone could toggle the variable on hardware not using it... SO my question stands, I want to know hardware details. Jack On Sun, Oct 2, 2011 at 5:29 PM, Arnaud Lacombe wrote: > Hi, > > On Sun, Oct 2, 2011 at 12:08 PM, Jack Vogel wrote: > > On what hardware? > > > Only the 82574 is using em(4)'s MSI-X. > > - Arnaud > > > 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" > > >