Date: Fri, 16 Jan 2015 20:12:35 +0100 From: Harald Schmalzbauer <h.schmalzbauer@omnilan.de> To: FreeBSD Stable <freebsd-stable@freebsd.org> Subject: lagg(8) causes ghost queue with igb(4) Message-ID: <54B962A3.9010308@omnilan.de>
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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--
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