From owner-freebsd-net@FreeBSD.ORG Fri Oct 29 17:23:52 2010 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 0A41A106566C for ; Fri, 29 Oct 2010 17:23:52 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from asmtpout028.mac.com (asmtpout028.mac.com [17.148.16.103]) by mx1.freebsd.org (Postfix) with ESMTP id E2A4F8FC0C for ; Fri, 29 Oct 2010 17:23:51 +0000 (UTC) MIME-version: 1.0 Content-type: text/plain; charset=koi8-r Received: from cswiger1.apple.com ([17.209.4.71]) by asmtp028.mac.com (Sun Java(tm) System Messaging Server 6.3-7.04 (built Sep 26 2008; 64bit)) with ESMTPSA id <0LB200BRTAYW1M10@asmtp028.mac.com> for freebsd-net@freebsd.org; Fri, 29 Oct 2010 10:23:21 -0700 (PDT) X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 suspectscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=6.0.2-1004200000 definitions=main-1010290114 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.2.15,1.0.148,0.0.0000 definitions=2010-10-29_09:2010-10-29, 2010-10-29, 1970-01-01 signatures=0 From: Chuck Swiger X-Priority: 3 (Normal) In-reply-to: <606859717.20101029093926@yandex.ru> Date: Fri, 29 Oct 2010 10:23:19 -0700 Content-transfer-encoding: quoted-printable Message-id: References: <1519248747.20101028232111@yandex.ru> <1452146D-A590-4676-A662-14D0EEE82152@mac.com> <606859717.20101029093926@yandex.ru> To: =?utf-8?B?0JrQvtC90YzQutC+0LIg0JXQstCz0LXQvdC40Lk=?= X-Mailer: Apple Mail (2.1081) Cc: freebsd-net@freebsd.org Subject: Re: Re[2]: Polling slows down bandwidth 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: Fri, 29 Oct 2010 17:23:52 -0000 On Oct 28, 2010, at 11:39 PM, =EB=CF=CE=D8=CB=CF=D7 =E5=D7=C7=C5=CE=C9=CA = wrote: > =FA=C4=D2=C1=D7=D3=D4=D7=D5=CA=D4=C5, Chuck. Um, greetings? =20 > =F7=D9 =D0=C9=D3=C1=CC=C9 28 =CF=CB=D4=D1=C2=D2=D1 2010 =C7., = 23:41:58: >=20 > CS> On Oct 28, 2010, at 1:21 PM, =EB=CF=CE=D8=CB=CF=D7 =E5=D7=C7=C5=CE=C9= =CA wrote: >>> [ ... ] >=20 > CS> What is "sysctl kern.clockrate", and have you increased kern.hz > CS> in /boot/loader.conf to at least 1000, if not 2000 or 4000? >=20 > # vmstat -i > interrupt total rate > irq14: ata0 193948 6 > irq16: rl0 42829515 1464 > irq23: nfe0 41224044 1409 > cpu0: timer 58494158 1999 > irq256: igb0 106911 3 > irq257: igb0 254606 8 > irq258: igb0 2 0 > Total 143103184 4892 >=20 > # sysctl kern.clockrate > kern.clockrate: { hz =3D 1000, tick =3D 1000, profhz =3D 2000, stathz = =3D 133 } >=20 > # sysctl kern.hz > kern.hz: 1000 > but I have configured and installed kern with 2000HZ > "systat -v" shows that: 2002 cpu0: time Actually, the interrupt rate is tracking profile hz, which is roughly = double the actual kern.hz-- per sysctl, you should try to at least = double kern.hz. >=20 > CS> Polling mode operation generally performs better when using older > CS> 100Mbs ethernet NICs which do not support interrupt mitigation and > CS> various capabilities like TSO4; gigabit ethernet NICs are smarter > CS> hardware and can generally outperform polling mode. >=20 > so using polling on gigabit NICs is a bottle neck? and is cause of low = performance, is not? Simple answer is yes. It should be possible that you could tune polling = to get similar performance, or at least better performance than you see = now, but the additional hardware capabilities of gigabit NICs are likely = to outperform polling mode, just as polling mode can generally = outperform old 100MBs ethernet NICs. Regards, --=20 -Chuck