From owner-freebsd-net@FreeBSD.ORG Wed Oct 1 09:15:18 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 03525F3D for ; Wed, 1 Oct 2014 09:15:18 +0000 (UTC) Received: from nijmegen.renzel.net (mx1.renzel.net [195.243.213.130]) by mx1.freebsd.org (Postfix) with ESMTP id B53C4323 for ; Wed, 1 Oct 2014 09:15:16 +0000 (UTC) Received: from dublin.vkf.isb.de.renzel.net (unknown [10.0.0.80]) by nijmegen.renzel.net (smtpd) with ESMTP id 6F017141486E for ; Wed, 1 Oct 2014 11:14:47 +0200 (CEST) Received: from asbach.renzel.net (unknown [10.2.0.7]) by dublin.vkf.isb.de.renzel.net (Postfix) with ESMTP id BABBC98529 for ; Wed, 1 Oct 2014 11:14:59 +0200 (CEST) Content-Type: text/plain; charset="ISO-8859-1" From: Nils Beyer Organization: VKF Renzel GmbH Date: Wed, 01 Oct 2014 11:14:59 +0200 User-Agent: KNode/4.12.5 Content-Transfer-Encoding: 7Bit Subject: Re: [CFT] alc(4) QAC AR816x/AR817x ethernet controller support To: freebsd-net@freebsd.org References: <20140930015741.GA2451@michelle.fasterthan.com> <20140930082053.4D9EFF8F@hub.freebsd.org> <20140930085228.GB969@michelle.fasterthan.com> <20140930093516.80A8943F@hub.freebsd.org> <20141001003954.GA2632@michelle.fasterthan.com> Lines: 36 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.98 at nijmegen.renzel.net X-Virus-Status: Clean X-Spam-Status: No, score=-6.5 required=7.0 tests=BAYES_00,MISSING_MID, UNPARSEABLE_RELAY autolearn=no version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on nijmegen.renzel.net 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, 01 Oct 2014 09:15:18 -0000 Hi, Yonghyeon PYUN wrote: > Default interrupt moderation policy is targeted to reduce latency > so it will generate up to 10k interrupts/sec under high network > load. If you want to reduce number of interrupts/sec, tune > interrupt moderation sysctl variables mentioned in alc(4). Tried several values here: dev.alc.0.int_rx_mod={1000,10000,100000} dev.alc.0.int_tx_mod={1000,10000,100000} but didn't notice any changes neither in CPU usage nor throughput during the "iperf" test; "kernel{alc0 taskq}" stays at 70-75%. I've downed/upped the interface "alc0" after every change. A simple iSCSI test using the native CTL interface works really well. A "fio" test results in 100MB/s read and write. Double-checking using "netstat -I" confirms gigabit-line speeds at around 120MB/s. CPU usage at "kernel{alc0 taskq}" is as high as in the "iperf" test. So I think that's a limitation of the AR8161 chip. > Updated the diff to address link establishment issue. > http://people.freebsd.org/~yongari/alc/pci.quirk.diff > http://people.freebsd.org/~yongari/alc/alc.diff.20141001 Confirmed; with the anti-hibernation patch, link estalishment is now working flawlessly. Thank you very much for your work... Regards, Nils