Subject: Re: [PATCH v5 6/8] tcp buffer limitation: per-cgroup limit

From: Glauber Costa <[email-masked]>
Date: Thu, 6 Oct 2011 12:38:59 +0400

On 10/05/2011 12:58 PM, Eric Dumazet wrote:
> Le mercredi 05 octobre 2011 à 12:08 +0400, Glauber Costa a écrit :
>> On 10/04/2011 04:48 PM, Eric Dumazet wrote:
>
>>> 2) Could you add const qualifiers when possible to your pointers ?
>>
>> Well, I'll go over the patches again and see where I can add them.
>> Any specific place site you're concerned about?
>
> Everywhere its possible :
>
> It helps reader to instantly knows if a function is about to change some
> part of the object or only read it, without reading function body.
Sure it does.

So, give me your opinion on this:

most of the acessors inside struct sock do not modify the pointers,
but return an address of an element inside it (that can later on be
modified by the caller.

I think it is fine for the purpose of clarity, but to avoid warnings we 
end up having to do stuff like this:

+#define CONSTCG(m) ((struct mem_cgroup *)(m))
+long *tcp_sysctl_mem(const struct mem_cgroup *memcg)
+{
+       return CONSTCG(memcg)->tcp.tcp_prot_mem;
+}

Is it acceptable?