From owner-freebsd-net@FreeBSD.ORG Mon Oct 3 00:29:45 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 267A0106566C for ; Mon, 3 Oct 2011 00:29:45 +0000 (UTC) (envelope-from lacombar@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 AF44C8FC12 for ; Mon, 3 Oct 2011 00:29:44 +0000 (UTC) Received: by wyj26 with SMTP id 26so3568630wyj.13 for ; Sun, 02 Oct 2011 17:29:43 -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:content-transfer-encoding; bh=EpHnlbYLErZtuApuoziA6WRkR5nDHrbYRiUK4vNx3xw=; b=kgAtPUgkWQfQwpGCSdQoxn1DmCKegEu4XpdRAqA4kbe8i54jSWVt8WRXIPqrtrwWbr b5QO92frLS8/5eZ5sJ86NyFcstBIa+0Wm6jktWBWZb7hCEJfEbiyJRTet23KbrgkvDV4 f4wiU5A9Ae1W60++C8xy2x7v+vuTdmGN+FaxM= MIME-Version: 1.0 Received: by 10.227.175.77 with SMTP id w13mr2224116wbz.36.1317601783091; Sun, 02 Oct 2011 17:29:43 -0700 (PDT) Received: by 10.180.103.33 with HTTP; Sun, 2 Oct 2011 17:29:43 -0700 (PDT) In-Reply-To: References: <4E886A3B.7000502@sepehrs.com> Date: Sun, 2 Oct 2011 20:29:43 -0400 Message-ID: From: Arnaud Lacombe To: Jack Vogel Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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 00:29:45 -0000 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 wrot= e: > >> >> Latest em(4) driver from HEAD seems to have high latency >> when MSIX is disabled. >> >> With MSIX enabled (hw.em.enable_msix=3D1): >> >> # 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=3D0 ttl=3D64 time=3D0.055 ms >> 64 bytes from 192.168.1.83: icmp_seq=3D1 ttl=3D64 time=3D0.076 ms >> 64 bytes from 192.168.1.83: icmp_seq=3D2 ttl=3D64 time=3D0.066 ms >> 64 bytes from 192.168.1.83: icmp_seq=3D3 ttl=3D64 time=3D0.051 ms >> 64 bytes from 192.168.1.83: icmp_seq=3D4 ttl=3D64 time=3D0.063 ms >> >> --- 192.168.1.83 ping statistics --- >> 5 packets transmitted, 5 packets received, 0.0% packet loss >> round-trip min/avg/max/stddev =3D 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=3D0 ttl=3D64 time=3D0.180 ms >> 64 bytes from 192.168.1.83: icmp_seq=3D1 ttl=3D64 time=3D0.164 ms >> 64 bytes from 192.168.1.83: icmp_seq=3D2 ttl=3D64 time=3D0.169 ms >> 64 bytes from 192.168.1.83: icmp_seq=3D3 ttl=3D64 time=3D0.172 ms >> 64 bytes from 192.168.1.83: icmp_seq=3D4 ttl=3D64 time=3D0.167 ms >> >> --- 192.168.1.83 ping statistics --- >> 5 packets transmitted, 5 packets received, 0.0% packet loss >> round-trip min/avg/max/stddev =3D 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: >> =A0 =A0- igb(4) from HEAD: OK. >> =A0 =A0- Stock 7.3-RELEASE: OK. >> =A0 =A0- 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" >