RE: Bogus frames transmitted with r8169 & fragmentation & large mtu

hayeswang
2012-02-21T02:59:11Z

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> From: Francois Romieu [mailto:romieu@fr.zoreil.com]
> Sent: Thursday, February 16, 2012 8:05 PM
> To: Hayeswang
> Cc: 'Eric Dumazet'; 'Nick Bowler'; netdev@vger.kernel.org
> Subject: Re: Bogus frames transmitted with r8169 &
> fragmentation & large mtu
>
> Francois Romieu <romieu@fr.zoreil.com> :
> [...]
> > I am testing it now.
>
> It does not fix the problem. It seems to make a difference but I still
> see a few percents packet loss. The pattern has changed a bit
> too: there
> are more bogus IP fragment offsets.
>
> Trying with 'ping -qf -c 100 -l 2 -s 65507 10.0.7.1'

It works fine for me. I use Linux platform (Fedora 16 with kernel 3.2.0 with
that patch) with the realtek nic to ping Windows platform with the NVIDIA nic,
and I connect the two PCs directly without the switch. It works well except for
the first packet after I set the new mtu.

>
> So far I have only seen it with the 2nd and last fragment.
>

Best Regards,
Hayes

[-- Attachment #2: ping.log --]
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[ 45.415894] r8169 0000:04:00.0: eth0: RTL8168d/8111d at 0xf7e58000, 00:e0:4c:68:00:04, XID 083000c0 IRQ 46
p33p1 Link encap:Ethernet HWaddr 00:E0:4C:68:00:04
inet addr:192.168.94.44 Bcast:192.168.94.255 Mask:255.255.255.0
inet6 addr: fe80::2e0:4cff:fe68:4/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:9000 Metric:1
RX packets:3714 errors:0 dropped:0 overruns:0 frame:0
TX packets:3670 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:28794250 (27.4 MiB) TX bytes:28919110 (27.5 MiB)
Interrupt:46 Base address:0x8000
PING 192.168.94.20 (192.168.94.20) 65507(65535) bytes of data.

--- 192.168.94.20 ping statistics ---
100 packets transmitted, 100 received, 0% packet loss, time 89ms
rtt min/avg/max/mdev = 1.368/1.643/1.954/0.099 ms, pipe 2, ipg/ewma 0.904/1.705 ms
PING 192.168.94.20 (192.168.94.20) 65507(65535) bytes of data.

--- 192.168.94.20 ping statistics ---
100 packets transmitted, 100 received, 0% packet loss, time 90ms
rtt min/avg/max/mdev = 1.419/1.658/1.943/0.078 ms, pipe 2, ipg/ewma 0.912/1.673 ms
Linux fc16.localdomain 3.2.0 #1 SMP Tue Jan 10 16:11:29 CST 2012 i686 i686 i386 GNU/Linux