From owner-freebsd-net@FreeBSD.ORG Wed Feb 11 21:30:00 2015 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id BDAFB70C for ; Wed, 11 Feb 2015 21:30:00 +0000 (UTC) Received: from mail.ignoranthack.me (ignoranthack.me [199.102.79.106]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 9BDE9FA0 for ; Wed, 11 Feb 2015 21:30:00 +0000 (UTC) Received: from [192.168.200.212] (unknown [50.136.155.142]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: sbruno@ignoranthack.me) by mail.ignoranthack.me (Postfix) with ESMTPSA id 39CD81941DD; Wed, 11 Feb 2015 21:29:59 +0000 (UTC) Message-ID: <54DBC9D6.7020602@ignoranthack.me> Date: Wed, 11 Feb 2015 13:29:58 -0800 From: Sean Bruno Reply-To: sbruno@freebsd.org User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Sepherosa Ziehau Subject: Re: Intel 82574L (em) References: <54CBF396.3090903@ignoranthack.me> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: "freebsd-net@freebsd.org" X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Feb 2015 21:30:00 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On 02/10/15 18:49, Sepherosa Ziehau wrote: > On Sat, Jan 31, 2015 at 5:11 AM, Sean Bruno > wrote: >> >> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 >> >> http://www.intel.com/content/dam/doc/datasheet/82574l-gbe-controller-datasheet.pdf >> >> >> According to 7.1.11, this device does indeed have 2 queues for stuff and >> or things. So, basic RSS would be possible in something like an >> Atom box. >> >> I note that the em(4) driver intentionally disables this on >> initialization. I'm up for some science on my new shiny, soon to >> be router box. Any reason not to default to 1 queue and allow >> loader.conf to raise it to 2? > > You could actually enable 2 RX rings w/o MSI-X on 82574; you still > get the benefit of hardware calculated RSS hash at least. And as > far as I have tested, 2 RX rings work for 82574L, but 2 TX rings > don't work (gave me TX watchdog timeout). And you could also use 2 > RX rings on 82571/82572/82573 and i217/i218; 2 TX rings work on > 82571 at least (you need to setup TX context for each TX descriptor > though). > > Best Regards, sephe > > I'm interested in doing this a bit as I now have 5 em(4) interfaces on my soon to be router box. I tried modifying the driver to allow num_queues to be raised and I compiled with EM_MULTIQUEUE set, and all I got for my trouble was kernel panics. I'm not sure if the code even works. sean -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQF8BAEBCgBmBQJU28nOXxSAAAAAAC4AKGlzc3Vlci1mcHJAbm90YXRpb25zLm9w ZW5wZ3AuZmlmdGhob3JzZW1hbi5uZXRCQUFENDYzMkU3MTIxREU4RDIwOTk3REQx MjAxRUZDQTFFNzI3RTY0AAoJEBIB78oecn5k+vMIAKaDtSR6Rr4jHnojPH0K8bbv 35khkxhHiPjynRRUxOtJXqlGu8rQ2s1L3hW8V+sKYq/sI+pjmVTMrRko6+nIdDf/ bJe20S1EQxbhm74HbO28hNnG5uBjNfEP0hwEuaZHRdenua1TtnmMSnWqOh7xT1i1 3573Bx2WulgYaEEtYmnXX5x5E8C8ks6Lr4ZQptkGPJXDBtw3v59/oc2GK/P3tixL QvNPkYbFkLn+9tD6kjy05E92BOpUG84u37rlldajxXzpRkN7xaczKMERQ2VZD4lD 8b48F4im/iElJ6fsvUSJhzqW+H/ywBOgaJEjDXJgzrz0ffaMwY8vfpp4cmDkzCE= =rlKy -----END PGP SIGNATURE-----