Date: Fri, 15 Sep 2006 14:22:28 +0400 From: Gleb Smirnoff <glebius@FreeBSD.org> To: Brooks Davis <brooks@one-eyed-alien.net> Cc: Andre Oppermann <andre@FreeBSD.org>, current@FreeBSD.org, John Baldwin <jhb@FreeBSD.org>, Mike Tancsa <mike@sentex.net>, Ian FREISLICH <if@hetzner.co.za>, freebsd-current@FreeBSD.org, Jack Vogel <jfvogel@gmail.com> Subject: Re: TSO, SMP and the em driver. Message-ID: <20060915102228.GK27667@FreeBSD.org> In-Reply-To: <20060913154622.GA52716@lor.one-eyed-alien.net> References: <E1GN5FA-00085C-CJ@hetzner.co.za> <7.0.1.0.0.20060912125903.15bdb7a0@sentex.net> <45073F58.6080900@freebsd.org> <200609131108.45382.jhb@freebsd.org> <20060913154622.GA52716@lor.one-eyed-alien.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Sep 13, 2006 at 10:46:22AM -0500, Brooks Davis wrote: B> On Wed, Sep 13, 2006 at 11:08:44AM -0400, John Baldwin wrote: B> > On Tuesday 12 September 2006 19:14, Andre Oppermann wrote: B> > > Mike Tancsa wrote: B> > > > At 12:43 PM 9/12/2006, Andre Oppermann wrote: B> > > > B> > > >> TSO != (vlan && promisc) B> > > > B> > > > Sorry, the commonality I was referring to was VLAN hardware tagging and B> > > > how it must be enabled for TSO, but that breaks other things. See a few B> > > > messages ago B> > > > B> > http://lists.freebsd.org/pipermail/freebsd-current/2006-September/065818.html B> > > B> > > I'm sure we can find a workaround for that. B> > B> > Well, you could have the em(4) driver manually handle TSO in software, which B> > is what it does to workaround the VLAN tag problem. (It does VLAN B> > encapsulation in the driver.) While VLAN insertion may be trivial, B> > re-implementing TCP segmentation in the driver might be a good bit less B> > trivial to do. There's not going to be a simple easy workaround for this B> > hardware bug. :( B> B> I'm not sure it's worth worrying about with GbE hardware. Just disable B> TSO in promiscuous mode. Where TSO is going to really matter is 10GbE. B> No supporting TSO in some configurations with GbE doesn't seem like a B> big deal to me. Yes, makeing TSO and promisc mutually exclusive would be fine. -- Totus tuus, Glebius. GLEBIUS-RIPN GLEB-RIPE
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20060915102228.GK27667>