Subject: Re: [PATCH] IPv4/IPv6: update sysctl files

From: Shen Feng <[email-masked]>
Date: Wed, 08 Apr 2009 16:50:49 +0800

on 04/08/2009 03:18 PM, David Miller wrote:
> From: Shen Feng <[email-masked]>
> Date: Wed, 08 Apr 2009 11:28:21 +0800
> 
>>
>> on 04/08/2009 10:47 AM, Ben Hutchings wrote:
>>> On Wed, 2009-04-08 at 02:39 +0000, Shen Feng wrote:
>>>> Now the following sysctl files in /proc/sys/net/ipv4 are used by
>>>> both IPv4 and IPv6.
>>>> tcp_mem  tcp_rmem  tcp_wmem
>>>> udp_mem  udp_rmem_min  udp_wmem_min
>>>> Putting them in /proc/sys/net/ipv4 is not a good choice.
>>> [...]
>>>
>>> But this is part of the ABI to userland.  You cannot remove sysctl files
>>> without long advance notice documented in feature-removal-schedule.txt
>>> (if at all).
>>>
>>> If it is possible to add the paths
>>> /proc/sys/net/{tcp,udp} while retaining aliases under /proc/sys/net/ipv4
>>> then that might be a workable solution.
>> Thanks. That's a good solution.
>>
>> But I'm still confused.
>> Why not create another tcp_mem in /proc/sys/net/ipv6?
> 
> People just need to understand that ipv4 is always going to be
> there and that's where all the tcp controls are.
> 
> I really am not going to entertain changes that try to move generic
> inet sysctl things out of the ipv4 directory.  There is really no
> point at all.
> 

/proc/sys/net/ipv4/tcp_mem is a inet sysctl, but it also controls the tcp v6.
So it's also a inet6 sysctl. Is it intentional?
This may confuse users. We may have a /proc/sys/net/ipv6/tcp6_mem.