Re: [PATCH net-next 1/2] tcp: call tcp_drop() in tcp collapse

[Yafang Shao]

On Mon, Jul 30, 2018 at 11:56 PM, Eric Dumazet <edumazet@xxxxxxxxxx> wrote:
> On Sun, Jul 29, 2018 at 10:40 PM Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
>
>> Should we put NET_INC_STATS(sock_net(sk),  mib_idx) into the funtion
>> tcp_drop() ?
>> Then we could easily relate the sk_drops with the SNMP counters.
>>
>> Something like that,
>>
>>     static void tcp_drop(struct sock *sk, struct sk_buff *skb, int mib_idx)
>>     {
>>         int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
>>
>>         atomic_add(segs, &sk->sk_drops);
>>         NET_ADD_STATS(sock_net(sk), mib_idx, segs);
>>         __kfree_skb(skb);
>>     }
>
> We had a discussion during netconf, and Brendan Gregg was working on
> an idea like that,
> so that distinct events could be traced/reported.
>

Oh yes, introducing a new tracepoint for it should be better.
trace_tcp_probe(sk, skb, mib_idx);

> I prefer letting Brendan submit his patch, which not only refactors
> things, but add new functionality.
>

OK.