Re: [PATCH v2 net] fq_codel: fix NET_XMIT_CN behavior

[Florian Westphal]

Jamal Hadi Salim <j...@mojatatu.com> wrote:
> BTW, returning NET_XMIT_CN could be confusing to tcp;
> it does not mean that the packet that we are getting return
> code for was dropped; it could mean _another_ packet in
> the queue was dropped.

Yes, but we currently conceal NET_XMIT_CN from upper layer (tcp)
via the net_xmit_* macros:

#define net_xmit_eval(e)       ((e) == NET_XMIT_CN ? 0 : (e))
#define net_xmit_errno(e)      ((e) != NET_XMIT_CN ? -ENOBUFS : 0)

Might be worth changing this so tcp reduces cwnd in _CN case too.