Re: Very slow realtek 8169 ethernet performance, but only one interface, on ThinkPad T14.

[Qu Wenruo]

On 2020/11/5 下午5:13, Heiner Kallweit wrote:
> On 05.11.2020 08:42, Qu Wenruo wrote:
>>
>>
>> On 2020/11/5 下午3:01, Heiner Kallweit wrote:
>>> On 05.11.2020 03:48, Qu Wenruo wrote:
>>>> Hi,
>>>>
>>>> Not sure if this is a regression or not, but just find out that after upgrading to v5.9 kernel, one of my ethernet port on my ThinkPad T14 (ryzen version) becomes very slow.
>>>>
>>>> Only *2~3* Mbps.
>>>>
>>>> The laptop has two ethernet interfaces, one needs a passive adapter, the other one is a standard RJ45.
>>>>
>>>> The offending one is the one which needs the adapter (eth0).
>>>> While the RJ45 one is completely fine.
>>>>
>>>> 02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0e)
>>>> 05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
>>>>
>>>> The 02:00.0 one is the affected one.
>>>>
>>>> The related dmesgs are:
>>>> [   38.110293] r8169 0000:02:00.0: can't disable ASPM; OS doesn't have ASPM control
>>>> [   38.126069] libphy: r8169: probed
>>>> [   38.126250] r8169 0000:02:00.0 eth0: RTL8168ep/8111ep, 00:2b:67:b3:d9:20, XID 502, IRQ 105
>>>> [   38.126252] r8169 0000:02:00.0 eth0: jumbo features [frames: 9194 bytes, tx checksumming: ko]
>>>> [   38.126294] r8169 0000:05:00.0: can't disable ASPM; OS doesn't have ASPM control
>>>> [   38.126300] r8169 0000:05:00.0: enabling device (0000 -> 0003)
>>>> [   38.139355] libphy: r8169: probed
>>>> [   38.139523] r8169 0000:05:00.0 eth1: RTL8168h/8111h, 00:2b:67:b3:d9:1f, XID 541, IRQ 107
>>>> [   38.139525] r8169 0000:05:00.0 eth1: jumbo features [frames: 9194 bytes, tx checksumming: ko]
>>>> [   42.120935] Generic FE-GE Realtek PHY r8169-200:00: attached PHY driver [Generic FE-GE Realtek PHY] (mii_bus:phy_addr=r8169-200:00, irq=IGNORE)
>>>> [   42.247646] r8169 0000:02:00.0 eth0: Link is Down
>>>> [   42.280799] Generic FE-GE Realtek PHY r8169-500:00: attached PHY driver [Generic FE-GE Realtek PHY] (mii_bus:phy_addr=r8169-500:00, irq=IGNORE)
>>>> [   42.477616] r8169 0000:05:00.0 eth1: Link is Down
>>>> [   76.479569] r8169 0000:02:00.0 eth0: Link is Up - 1Gbps/Full - flow control rx/tx
>>>> [   91.271894] r8169 0000:02:00.0 eth0: Link is Down
>>>> [   99.873390] r8169 0000:02:00.0 eth0: Link is Up - 1Gbps/Full - flow control rx/tx
>>>> [   99.878938] r8169 0000:02:00.0 eth0: Link is Down
>>>> [  102.579290] r8169 0000:02:00.0 eth0: Link is Up - 1Gbps/Full - flow control rx/tx
>>>> [  185.086002] r8169 0000:02:00.0 eth0: Link is Down
>>>> [  392.884584] r8169 0000:02:00.0 eth0: Link is Up - 1Gbps/Full - flow control rx/tx
>>>> [  392.891208] r8169 0000:02:00.0 eth0: Link is Down
>>>> [  395.889047] r8169 0000:02:00.0 eth0: Link is Up - 1Gbps/Full - flow control rx/tx
>>>> [  406.670738] r8169 0000:02:00.0 eth0: Link is Down
>>>>
>>>> Really nothing strange, even it negotiates to 1Gbps.
>>>>
>>>> But during iperf3, it only goes up to miserable 3Mbps.
>>>>
>>>> Is this some known bug or something special related to the passive adapter?
>>>>
>>>> Since the adapter is passive, and hasn't experience anything wrong for a long time, I really doubt that.
>>>>
>>>> Thanks,
>>>> Qu
>>>>
>>>>
>>> Thanks for the report. From which kernel version did you upgrade?
>>
>> Tested back to v5.7, which still shows the miserable performance.
>>
>> So I guess it could be a faulty adapter?
>>
>>> Please test
>>> with the prior kernel version and report behavior (link stability and speed).
>>> Under 5.9, does ethtool -S eth0 report packet errors?
>>>
>> Nope, no tx/rx_errors, no missed/aborted/underrun.
>>
>> Adding that the adapter is completely passive (no chip, just converting
>> RJ45 pins to the I shaped pins), I'm not sure that the adapter itself
>> can fail.
>>
> Each additional mechanical connection may cause reflections or other signal
> disturbance. You could try to restrict the speed to 100Mbps via ethtool,
> and see what the effective speed is then. 100Mbps uses two wire pairs only.

OK, you're right, now I can get around 60Mbps.

So definitely something wrong with the adapter.

Will use the RJ45 one and avoid use the ThinkPad proprietary interface.

Thanks,
Qu
> 
>> THanks,
>> Qu
>>
>

Attachment: signature.asc
Description: OpenPGP digital signature