Re: [PATCH net-next] net/smc: introduce shadow sockets for fallback connections

[Kai <KaiShen@linux.alibaba.com>]

On 3/22/23 9:08 PM, Paolo Abeni wrote:
> 
> It looks like only the shadow sockets' receive queue is needed/used.
> 
> Have you considered instead adding 2 receive queues to smc_sock, and
> implement a custom accept() variant fetching the accepted sockets from
> there?
> 
> That will allow better encapsulating the changes into the smc code and
> will avoid creating that 2 non-listening but almost listening sockets
> which look quite strange.
> 
> Cheers,
> 
> Paolo

I am not so sure about this two sockets implementation but Here are my
concerns:
1. When I tried to implement a custom accept, I found the function.
mem_cgroup_charge_skmem is not exported and SMC-R couldn't access it as
a module. If there are more functions like this in future updates this
could be a problem.
3. The custom accept should synchronize with future updates of TCP
accept.
2. SMC-R is trying to behave like TCP and if we implement custom accept,
there may be repeated code and looks not good.

Thanks,

Kai