Date: Wed, 22 Nov 2017 09:04:53 +0100 From: Vincenzo Maffione <v.maffione@gmail.com> To: Harry Schmalzbauer <freebsd@omnilan.de> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, Giuseppe Lettieri <g.lettieri@iet.unipi.it> Subject: Re: netmap/vale periodic deadlock Message-ID: <CA%2B_eA9gW9mkCTr2JzMz4nqdhY%2BtaGshStrVxLO3QOQ7MoUhWFg@mail.gmail.com> In-Reply-To: <5A149107.9060507@omnilan.de> References: <5A0F14CD.3040407@omnilan.de> <CA%2B_eA9giPsMJ2_O1CLvOro=rMm5TaJyQ-et_U01Re5J9%2B9VSqg@mail.gmail.com> <5A149107.9060507@omnilan.de>
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2017-11-21 21:48 GMT+01:00 Harry Schmalzbauer <freebsd@omnilan.de>: > Bez=C3=BCglich Vincenzo Maffione's Nachricht vom 21.11.2017 09:39 (localt= ime): > =E2=80=A6 > > > > If this is the case, although you are allowed to do that, I don't think > > it's a convenient way to use netmap. > > Since VLAN interfaces like vlan0 do not have (and cannot have) native > > netmap support, you are falling back to emulated netmap adapters (which > > are probably buggy on FreeBSD, specially when combined with VALE). > > Apart from bugs I think that with this setup you can't get decent > > performance that would justify using netmap rather than the standard > > kernel bridge and TAP devices. > > Hello, > > lockup happened earlier than expected. > This time 'vale-ctl' still reported (-l) the configuration. > One guest, using if_vtnet(4)-virtio-net#vale2:korso, showed: > dmz: watchdog timeout on queue 0 > (dmz is the renamed if_vtnet(4)) > > I could attach tcpdump to the uplink interface and also to all vlan > children. > Complete silence everywhere. So it seems the nic stopped processing > anything. > > Do you think that symptom could be caused by my special vale > integration, so that bugs in netmap emulation could crash the NIC? > Or is it unlikely that this is related. > > I hadn't prepared a debug kernel for the host, so the machine rebooted > without again. > I think I'll have to start with replacing vale first, to narrow down > possible causes. Today I was lucky, the lockup happend after business > hours, but I won't rely on that. > At least I know if I really need to look for a debug netmap kernel, or > possibly there's something else... > > Thanks, > > -harry > I can't really say anything without a stack trace or meaningful logs. There is a thing that you may do to see if the bug comes out of a bad interaction between emulated netmap and VALE. Instead of attaching the vlan interfaces to VALE you can connect VALE to the vlan interface through the "bridge" program. In this way nothing changes from the functional point of view, but you are not attaching anymore the VLAN interface to VALE (and you are using an additional process). So instead of # vale-ctl vale0:vlan0 you would have # bridge netmap:vlan0 vale0:vv # "vv" can be anything Cheers, Vincenzo --=20 Vincenzo Maffione
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