Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
In-Reply-To: <CANn89iK4KLHww-R2JmNr-tYVcUWevq6ceFQW0qE2mJCsq6eL-g@mail.gmail.com>
References: <1532746900-11710-1-git-send-email-laoar.shao@gmail.com>
 <CANn89iJ=Ad7sVWr3zBmXNSyePJJZaxgnMymN8S7x6fCSvG2jTQ@mail.gmail.com>
 <CALOAHbC4Rs7w1RwZRBsw_fjGSDvuHV37=nguzJNZzkreR5f4Dw@mail.gmail.com>
 <CANn89iKXPu=RKkLop4NJWZLixE__qYV2S=PngSj6ienuvWWL8g@mail.gmail.com>
 <CALOAHbAjtNf1LOhWEJMKNEEHSxjfEKiVV22KPUK88CTzt-eW0w@mail.gmail.com>
 <CANn89i+12HvAsvk9crDcqGh=v-DvLjuGQCOzVTPVDTUhHgeDiw@mail.gmail.com>
 <CALOAHbBFuASgsQK+iiAE+ebPOg5zjtzauYaN_Xtmfc9_wjTFgw@mail.gmail.com>
 <CANn89i+0peAq_BS3Ge-h2_MENHQAHtf8D_M0gzgchK6CxU8D+Q@mail.gmail.com>
 <CALOAHbBy6wEwDcVaWx9PG35jknwkhM-Y-TVyis3TpVQYr5K-Jw@mail.gmail.com> <CANn89iK4KLHww-R2JmNr-tYVcUWevq6ceFQW0qE2mJCsq6eL-g@mail.gmail.com>
From:   Yafang Shao <laoar.shao@gmail.com>
Date:   Tue, 31 Jul 2018 08:48:49 +0800
Message-ID: <CALOAHbCcK5OoGn1Zc_CDYwM9FXKgi0wk8zq8xB1wHyH4iZTxZA@mail.gmail.com>
Subject: Re: [PATCH net-next 1/2] tcp: call tcp_drop() in tcp collapse
To:     Eric Dumazet <edumazet@google.com>
Cc:     Brendan Gregg <bgregg@netflix.com>,
        David Miller <davem@davemloft.net>,
        netdev <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, Jul 30, 2018 at 11:56 PM, Eric Dumazet <edumazet@google.com> wrote:
> On Sun, Jul 29, 2018 at 10:40 PM Yafang Shao <laoar.shao@gmail.com> 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.