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

From: Glauber Costa
Date: Thu Oct 06 2011 - 04:39:36 EST

On 10/05/2011 12:58 PM, Eric Dumazet wrote:
Le mercredi 05 octobre 2011 Ã 12:08 +0400, Glauber Costa a Ãcrit :
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?
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