Re: r8169 and out of space

[Nathan Grennan <alistair@cygnusx-1.org>]

Francois Romieu wrote:
> Alistair John Strachan <alistair@devzero.co.uk> :
> [..]
>   
>> No, we have not diagnosed the cause of the problem, beyond the swiotlb usage. 
>> I'm adding the r8169 maintainer, linux-net and linux-kernel to CC, to pass on 
>> your information, I hope you don't mind.
>>     
>
> swiotlb fragmentation perhaps ?
>
> Switching the driver to be page based on Rx would help then.
>
> [...]
>   
>>>   I have a Abit AB9 Pro motherboard with Intel P965 chipset, 4gb of
>>> memory, and two onboard r8169.
>>>       
>
> Which r8169 model exactly ?
>
>   
  I seem to have been wrong about the kernel update fixing my mtu issue. 
I am not 100% sure, but I think 7200 works if the forcedeth system is 
sending, but not if the r8169 system is sending.

  I tried a mtu of 3000, and basically the same errors, but I did 
noticed something interesting. Note the three different byte sizes.

DMA: Out of SW-IOMMU space for 2410 bytes at device 0000:03:00.0
DMA: Out of SW-IOMMU space for 3014 bytes at device 0000:03:00.0
DMA: Out of SW-IOMMU space for 3014 bytes at device 0000:03:00.0
DMA: Out of SW-IOMMU space for 3022 bytes at device 0000:03:00.0


  On a side note, leaving the mtu at 1500 seems to work without error, 
and I get about the same performance.