Re: [PATCH net-next] r8169: migrate Rx path to page_pool

[Heiner Kallweit <hkallweit1@gmail.com>]

On 17.06.2026 05:28, Atharva Potdar wrote:
> Hi Heiner, Francois,
> Thank you for reviewing this patch.
> 
> Francois:
>> You may consider fdd7b4c3302c93f6833e338903ea77245eb510b4 and some related
>> changes around that time.
> 
> I am sorry but I don't fully understand the context of this commit or
> the behaviour it addresses. Could you please help me regarding what I
> need to watch out for this change?
> 
> Heiner:
>> Assuming your link speed is 1Gbps, 470Mbps is quite low.
> 
> I apologize, that was my benchmark figure when I passed my NIC via
> VFIO to a VM for testing. When I tested it bare metal again with
> iperf3, I hit line rates of 941 Mbps.
> 
>> If I read this correctly, max_mtu may be lower with this patch.
>> This may cause a regression for existing users.
> 
> My main intention for restricting to order-0 pages is to prepare the
> driver for XDP support in the subsequent patches. I understand this
> causes a regression but I am not sure of another way to tackle it. How
> do you prefer I handle this to avoid breaking current setups while
> still having the driver be ready for XDP?
> 
>> Did you test also on non-x86 architectures? We had DMA-related regressions
>> in the past which showed up on certain non-x86 architectures only.
> 
> Unfortunately, I currently only have access to x86 hardware. I cannot
> test this on a bare-metal ARM machine, only an ARM VM - which may not
> show those hardware issues. How is the testing typically handled for
> other architectures in a situation like this?
> 
It's not only about ARM, I'm aware of at least loongarch systems with
such Realtek NICs. If you can't test it, then you should at least
ensure that in theory the DMA-related flags are OK for basically
any architecture.

> Thanks,
> Atharva.