Re: [PATCH net] net: bcmgenet: allocate RX buffers as page fragments

[Karl Mehltretter]

On Thu, Sep 24, 2026 at 12:19:21PM +0100, Nicolai Buchwitz wrote:
> Fix this and allocate the buffers as page fragments, so the truesize is
> what a packet occupies. 4 KiB pages stay one buffer per page.
> 

Tested-by: Karl Mehltretter <kmehltretter@xxxxxxxxx>

I applied this unchanged to current net at 11536ee3d3e0, current net-next at
42a9fb3382fc, and after patches 129 and 130 from 6.18.54-rc1. I tested each
with a 64 KiB arm64 kernel in a custom QEMU Pi 400 model with GENET v5 DMA.

My LLM agent helped me running these tests.

Results with a 524,288-byte receive buffer (repeated over five rounds):

                             Unpatched net   Patched net/net-next
Charge per 512-byte UDP      65,792 bytes    2,624 bytes
Datagrams queued (of 1,000)  7               195
Socket drops                 993             805

Thanks,
Karl