From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Samuelson Subject: Re: TCP stalls with 802.3ad + bridge + kvm guest Date: Wed, 1 Aug 2012 09:41:04 -0500 Message-ID: <20120801144104.GN17572@p12n.org> References: <20120727183840.GE17572@p12n.org> <26496.1343419205@death.nxdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: jgoerzen@efolder.net To: Jay Vosburgh , netdev@vger.kernel.org Return-path: Received: from mx11.dcmx.net ([207.210.100.175]:53293 "EHLO mx11.dcmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754756Ab2HAOlH (ORCPT ); Wed, 1 Aug 2012 10:41:07 -0400 Content-Disposition: inline In-Reply-To: <26496.1343419205@death.nxdomain> Sender: netdev-owner@vger.kernel.org List-ID: [Peter Samuelson] > > ixgbe [10 Gbit port] -- bonding [802.3ad] -- bridge -- KVM guest > > > >It all works, except that with some flows in the KVM guest - I > >can reproduce using smbclient - transfers keep stalling, such that I'm > >averaging well under 1 MB/s. Should be more like 100 MB/s. > > > >Oddly, this only occurs when both the 802.3ad and KVM are used: > > > > Server Agg Client TCP stalls > > -------------------------------------------------- > > external none KVM guest no > > external 802.3ad KVM host no > > KVM host 802.3ad KVM guest no > > external 802.3ad KVM guest yes [Jay Vosburgh] > Does the problem happen if the bond is a different mode > (balance-xor, for example)? No, the balance-xor mode seems to work normally. I am testing it with only a single slave interface, same way I'm testing LACP mode. > Do the various stats on the host and guest show any drops? > E.g., from "netstat -i" and "tc -s qdisc" I am not sure what to make of 'netstat -i'. Some test boots, I get 26000 or so RX packets dropped on bond0 and eth2 (the slave interface), but not during the actual file transfer tests. The current test boot, with LACP enabled, 'netstat -i' shows only 19 dropped RX packets from bond0 (compared to 740k total RX packets), after several test runs. Thanks, Peter