Date: Wed, 22 Nov 2017 10:25:09 +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_eA9hH%2B6yPO6q=kASQGSVRiK8tq6qV666c5yc1JZvi_BujWg@mail.gmail.com> In-Reply-To: <5A154102.10007@omnilan.de> References: <5A0F14CD.3040407@omnilan.de> <CA%2B_eA9giPsMJ2_O1CLvOro=rMm5TaJyQ-et_U01Re5J9%2B9VSqg@mail.gmail.com> <5A149107.9060507@omnilan.de> <CA%2B_eA9gW9mkCTr2JzMz4nqdhY%2BtaGshStrVxLO3QOQ7MoUhWFg@mail.gmail.com> <5A1537B3.9030603@omnilan.de> <5A154102.10007@omnilan.de>
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Hi, $ bridge -h for usage. Yes, bridge is just a simple example program, and stays in foreground. Probably using daemon(8) you can turn it into a daemon. Cheers, Vincenzo 2017-11-22 10:18 GMT+01:00 Harry Schmalzbauer <freebsd@omnilan.de>: > Bez=C3=BCglich Harry Schmalzbauer's Nachricht vom 22.11.2017 09:39 (loca= ltime): > > Bez=C3=BCglich Vincenzo Maffione's Nachricht vom 22.11.2017 09:04 (loca= ltime): > >> > >> 2017-11-21 21:48 GMT+01:00 Harry Schmalzbauer <freebsd@omnilan.de > >> <mailto:freebsd@omnilan.de>>: > >> > >> Bez=C3=BCglich Vincenzo Maffione's Nachricht vom 21.11.2017 09:39 > >> (localtime): > >> =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 decen= t > >> > 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 vla= n > >> children. > >> Complete silence everywhere. So it seems the nic stopped processi= ng > >> 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 do= wn > >> 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 > > Hello Vincenzo, > > > > thank you very much for that interesting hint. > > I prepared a netgraph setup yesterday evening, but I'll try your > > suggestion first. Unfortunately I don't have time to prepare a debug > > Since this doesn't need a reboot and I'm in adventure mood, I just tried > it at runtime. > Unfortunately I can't find bridge documentation besides the source code. > It doesn't detach from terminal here: > bridge built Oct 8 2017 > 12:59:57 > > 060.359974 main [244] ------- zerocopy NOT > supported > > 060.359987 main [251] Wait 4 secs for link to come up... > 064.365872 main [255] Ready to go, nic1_egn 0x0/1 <-> vale4:nic1egn > 0x0/1. > > 068.084364 main [306] poll timeout [0] ev 1 0 rx 0@33 tx 1022, [1] ev 1 > 0 rx 0@34 tx > 1023 > 072.565559 main [306] poll timeout [0] ev 1 0 rx 0@34 tx 1022, [1] ev 1 > 0 rx 0@35 tx 1023 > =E2=80=A6 > > In general, things are working. > > Is bridge staing in the foreground by design? > > Thanks, > > -harry > --=20 Vincenzo Maffione
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