RE: [PATCH net-next 4/6] r8152: support new chips

From: Hayes Wang
Date: Tue Apr 20 2021 - 22:24:01 EST


Jakub Kicinski <kuba@xxxxxxxxxx>
> Sent: Wednesday, April 21, 2021 2:34 AM
[...]
> > We test 2.5G Ethernet on some embedded platform.
> > And we find 64 is not large enough, and the performance
> > couldn't reach 2.5 G bits/s.
>
> Did you manage to identify what the cause is?
>
> NAPI will keep calling your driver if the budget was exhausted, the
> only difference between 64 and 256 should be the setup cost of the
> driver's internal loop. And perhaps more frequent GRO flush - what's
> the CONFIG_HZ set to?

I am not sure. It is more than one year ago.
The CONFIG_HZ may be 250.

First, the CPU of that platform is slower than a x86 platform.
Then, the rx data comes very fast, because of the 2.5G Ethernet.
We find the budget is always exhausted, when the traffic is busy.

Best Regards,
Hayes