Re: 1e918876 breaks r8169 (linux-3.18+)

[Florian Westphal <fw@strlen.de>]

Florian Westphal <fw@strlen.de> wrote:
> Tomas Szepe <szepe@pinerecords.com> wrote:
> > Hi,
> > 
> > Since linux-3.18.0, r8169 is having problems driving one of my add-on
> > PCIe NICs.  The interface is losing link for several seconds at a time,
> > the frequency being about once a minute when the traffic is high.
> > 
> > The first loss of link is accompanied by the message "NETDEV WATCHDOG:
> > eth1 (r8169): transmit queue 0 timed out" and a call trace, while
> > subsequent occurrences only report "r8169 0000:01:00.0 eth1: link up"
> > (w/o the complementary "link down" message).
> > 
> > I've traced the culprit down to commit 1e918876, "r8169: add support
> > for Byte Queue Limits" by Florian Westphal <fw@strlen.de>.  Reverting
> > the patch appears to fix the problem on linux-3.18.5.
> > The same issue might already have been reported by Marco Berizzi here:
> > http://lkml.org/lkml/2014/12/11/65
> 
> Thanks for reporting this!  I'm no lkml subscriber and thus did not
> see earlier report.
> 
> I'll try to reproduce this but unfortunately I am currently travelling
> and won't have access to my r8169 nic until Feb 10th.

I tried to reproduce this without success so far on my RTL8168d/8111d device.
I've been running 40 parallel netperf TCP_STREAM tests (1gbit) for the
last 5 hours and so far I saw no watchdog tx timeouts.

I'll keep this running for a day or so to see if it just takes more time
to trigger.

Do you use any "special" settings (e.g. offload features off, mtu > 1500, etc)?

Thanks.