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Subject: Re: [PATCH net-next] tcp: add SNMP counter for the number of packets
 pruned from ofo queue
To:     Yafang Shao <laoar.shao@gmail.com>, davem@davemloft.net,
        edumazet@google.com
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org
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From:   Eric Dumazet <eric.dumazet@gmail.com>
Message-ID: <047bc12f-9eb5-e512-10c5-6334c494c77e@gmail.com>
Date:   Wed, 25 Jul 2018 06:33:41 -0700
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On 07/25/2018 06:06 AM, Yafang Shao wrote:
> LINUX_MIB_OFOPRUNED is used to count how many times ofo queue is pruned,
> but sometimes we want to know how many packets are pruned from this queue,
> that could help us to track the dropped packets.
> 
> As LINUX_MIB_OFOPRUNED is a useful event for us, so I introduce a new
> SNMP counter LINUX_MIB_OFOPRUNEDROP, which could be showed in netstat as
> OfoPruneDrop.


Okay, but why tracking number of skbs that are removed ?

Skb can contain many segments (because of GRO and TCP coalescing)

So your claim of tracking dropped packets is ill defined.

Also I prefer having net tree being merged into net-next, since your patch would
add a merge conflict.