Subject: Re: [PATCH net-next 5/5] net: sctp: fix and consolidate SCTP checksumming code

From: Vlad Yasevich <[email-masked]>
Date: Mon, 04 Nov 2013 11:10:12 -0500

On 11/04/2013 07:11 AM, Daniel Borkmann wrote:
> On 10/30/2013 03:29 PM, Vlad Yasevich wrote:
>> On 10/30/2013 06:50 AM, Daniel Borkmann wrote:
> [...]
>> Daniel
>>
>> Here is a follow-on idea that might help even more.
>> What if we put a pointer to skb_checksum_ops() in the skb
>> somewhere (I was thinking of skb_shinfo).  Then
>> skb_checksum can simply use the data from there.  This would
>> allow us to get rid of all the special cases in SCTP that do
>> checksumming.  We can just set it to partial, set up the right
>> fields and let HW or SW always do the right thing.
>
> I need to think about this a bit. This would certainly have the
> negative side-effect of a higher skb->truesize usage and thus
> affecting memory accounting for everyone as we extend
> skb_shared_info.

You are talking a single pointer here...  The alternative
is to do a per-protocol table.

-vlad