Re: [PATCH net] ppp: linearize bridged packets when required

[Qingfang Deng]

On 2026/10/22 1:55, Eric Dumazet wrote:
> > What about NETIF_F_FRAGLIST?
> I do not see your point. Can you elaborate?
>
> There’s also nothing left to gain on fraglist packets.
>
> SKB_GSO_FRAGLIST packets already go through skb_segment_list(),
> which just unchains the original skbs without copying, as the fraglist
> test run showed.
>
> Frag_list skbs that aren’t fraglist GRO go through skb_segment(),
> which with NETIF_F_SG already shares the pages of the chained skbs
> instead of copying them.

I've run selftests and confirmed that NETIF_F_FRAGLIST is unnecessary here.

One extra finding: passing NETIF_F_SG conditionally can avoid an extra 
reallocation in skb_linearize().

segs = skb_gso_segment(skb, chan->direct_xmit ? NETIF_F_SG : 0);