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Subject: Re: [PATCH net-next v4] net: linux/skbuff.h: combine SKB_EXTENSIONS +
 KCOV handling
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Florian Westphal <fw@strlen.de>,
        Matthieu Baerts <matthieu.baerts@tessares.net>,
        linux-kernel@vger.kernel.org, kernel test robot <lkp@intel.com>,
        Aleksandr Nogikh <nogikh@google.com>,
        Willem de Bruijn <willemb@google.com>,
        linux-next@vger.kernel.org, netdev@vger.kernel.org
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 <20201116143121.GC22792@breakpoint.cc>
 <20201116073013.24d45385@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
From:   Randy Dunlap <rdunlap@infradead.org>
Message-ID: <53e73344-3a3a-4a11-9914-8490efa1a3b9@infradead.org>
Date:   Mon, 16 Nov 2020 09:08:56 -0800
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On 11/16/20 7:30 AM, Jakub Kicinski wrote:
> On Mon, 16 Nov 2020 15:31:21 +0100 Florian Westphal wrote:
>>>> @@ -4151,12 +4150,11 @@ enum skb_ext_id {
>>>>   #if IS_ENABLED(CONFIG_MPTCP)
>>>>   	SKB_EXT_MPTCP,
>>>>   #endif
>>>> -#if IS_ENABLED(CONFIG_KCOV)
>>>>   	SKB_EXT_KCOV_HANDLE,
>>>> -#endif  
>>>
>>> I don't think we should remove this #ifdef: the number of extensions are
>>> currently limited to 8, we might not want to always have KCOV there even if
>>> we don't want it. I think adding items in this enum only when needed was the
>>> intension of Florian (+cc) when creating these SKB extensions.
>>> Also, this will increase a tiny bit some structures, see "struct skb_ext()".  
>>
>> Yes, I would also prefer to retrain the ifdef.
>>
>> Another reason was to make sure that any skb_ext_add(..., MY_EXT) gives
>> a compile error if the extension is not enabled.
> 
> Oh well, sorry for taking you down the wrong path Randy!

No problem.
So we are back to v2, right?
Do I need to resend that one?

thanks.
-- 
~Randy