Re: [PATCH net-next] net: airoha: Add TCP LRO support

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 12 Jun 2025 23:02:30 +0200 Lorenzo Bianconi wrote:
> > I'm not Eric but FWIW 256B is not going to help much. It's best to keep
> > the len / truesize ratio above 50%, so with 32k buffers we're talking
> > about copying multiple frames.  
> 
> what I mean here is reallocate the skb if the true size is small (e.g. below
> 256B) in order to avoid consuming the high order page from the page_pool. Maybe
> we can avoid it if reducing the page order to 2 for LRO queues provide
> comparable results.

Hm, truesize is the buffer size, right? If the driver allocated n bytes
of memory for packets it sent up the stack, the truesizes of the skbs
it generated must add up to approximately n bytes.

So if the HW places one aggregation session per buffer, and the buffer
is 32kB -- to avoid mem use ratio < 25% you'd need to copy all sessions
smaller than 8kB?

If I'm not making sense - just ignore, I haven't looked at the rest of
the driver :)