From: Jon Maloy
> Sent: 15 November 2017 20:24
> The socket level flow control is based on the assumption that incoming
> buffers meet the condition (skb->truesize / roundup(skb->len) <= 4),
> where the latter value is rounded off upwards to the nearest 1k number.
> This does empirically hold true for the device drivers we know, but we
> cannot trust that it will always be so, e.g., in a system with jumbo
> frames and very small packets.
I'd be more worried about drivers that set skb->truesize to the amount
of data in the skb rather than the memory used by the skb.
Last I looked some of the usbnet drivers lied badly.
David
