Re: [PATCH net-next] net: init sk_cookie for inet socket

[Eric Dumazet]

On 04/23/2018 08:58 AM, David Miller wrote:
> From: Yafang Shao <laoar.shao@xxxxxxxxx>
> Date: Sun, 22 Apr 2018 21:50:04 +0800
> 
>> With sk_cookie we can identify a socket, that is very helpful for
>> traceing and statistic, i.e. tcp tracepiont and ebpf.
>> So we'd better init it by default for inet socket.
>> When using it, we just need call atomic64_read(&sk->sk_cookie).
>>
>> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> 
> Applied, thank you.
> 

This is adding yet another atomic_inc on a global cache line.

Most applications do not need the cookie being ever set.

The existing mechanism was fine. Set it on demand.