Re: [PATCH net-next] tcp: add SNMP counter for the number of packets pruned from ofo queue

From: Eric Dumazet
Date: Wed Jul 25 2018 - 09:33:45 EST




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.