From owner-freebsd-stable@FreeBSD.ORG Fri Jan 16 19:12:45 2015 Return-Path: Delivered-To: freebsd-stable@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 DD7AF49B for ; Fri, 16 Jan 2015 19:12:45 +0000 (UTC) Received: from mx0.gentlemail.de (mx0.gentlemail.de [IPv6:2a00:e10:2800::a130]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 507581AB for ; Fri, 16 Jan 2015 19:12:45 +0000 (UTC) Received: from mh0.gentlemail.de (mh0.gentlemail.de [78.138.80.135]) by mx0.gentlemail.de (8.14.5/8.14.5) with ESMTP id t0GJCgbO043691 for ; Fri, 16 Jan 2015 20:12:42 +0100 (CET) (envelope-from h.schmalzbauer@omnilan.de) Received: from titan.inop.mo1.omnilan.net (titan.inop.mo1.omnilan.net [IPv6:2001:a60:f0bb:1::3:1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mh0.gentlemail.de (Postfix) with ESMTPSA id 0AE67A93; Fri, 16 Jan 2015 20:12:41 +0100 (CET) Message-ID: <54B962A3.9010308@omnilan.de> Date: Fri, 16 Jan 2015 20:12:35 +0100 From: Harald Schmalzbauer Organization: OmniLAN User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; de-DE; rv:1.9.2.8) Gecko/20100906 Lightning/1.0b2 Thunderbird/3.1.2 MIME-Version: 1.0 To: FreeBSD Stable Subject: lagg(8) causes ghost queue with igb(4) X-Enigmail-Version: 1.1.2 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigF3C3217F2F3F5BD778CE7AB2" X-Greylist: ACL 119 matched, not delayed by milter-greylist-4.2.7 (mx0.gentlemail.de [78.138.80.130]); Fri, 16 Jan 2015 20:12:42 +0100 (CET) X-Milter: Spamilter (Reciever: mx0.gentlemail.de; Sender-ip: 78.138.80.135; Sender-helo: mh0.gentlemail.de; ) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Jan 2015 19:12:46 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigF3C3217F2F3F5BD778CE7AB2 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi all, while investigating a watchdog timeout problem (on FreeBSD-10.1-stable r276295) I noticed "ghost" queues consuming interrupts with igb(4)[82576] if igb(4) is member of lagg(4) (laggproto loadbalance lagghash l2). Mysteriously only sometimes (1 of 2 runs). Sending machine has only one ssh session open, where I do the following: 'dd if=3D/dev/zero | nc vegashare 3333' (of course on vegashare is a listener [nc -l vegashare 3333 > /dev/null]) I'm transfering 123.5*10^6 Bytes/sec and on the sender, systat reports: 2682 igb0:que 0 (1 of 4 queues causes moderate irq load hw.igb.aim=3D1, otherhise it were 16k irqs/s, nothing on the other 3 queues) But roughly every second run, I see a another queue consuming much more irqs/s while transferring exactly the same at exactly the same speed: 7740 igb0:que 0 2640 igb0:que 3 Here's again one queue with 2.6k irqs/s, but another one with 7.7k irqs/s which I can't understand what this is doing. It's useless for sure, because with only one queue I get the same payload transported on the same hardware with the same speed and 3 queues idle=E2=80=A6 I removed lagg(4) from the party and the 2nd queue hasn't showed up for at least 20 test runs. So I guess it's caused by lagg(4). Does anybody have an explanation for this? Thanks, -Harry --------------enigF3C3217F2F3F5BD778CE7AB2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (FreeBSD) iEYEARECAAYFAlS5YqkACgkQLDqVQ9VXb8gP5gCbBo9rGkv1uutSUAP+DApsBSsU xNMAnRgpWnq8bax31ARa372k7B18CcjX =qUmT -----END PGP SIGNATURE----- --------------enigF3C3217F2F3F5BD778CE7AB2--