Re: [PATCH net-next] net: generalize calculation of skb extensions length

From: linux
Date: Wed Aug 23 2023 - 06:12:15 EST


Hi Jakub,


Aug 23, 2023 03:46:48 Jakub Kicinski <kuba@xxxxxxxxxx>:

> On Tue, 22 Aug 2023 08:51:57 +0200 Thomas Weißschuh wrote:
>> Remove the necessity to modify skb_ext_total_length() when new extension
>> types are added.
>> Also reduces the line count a bit.
>>
>> With optimizations enabled the function is folded down to a constant
>> value as before.
>
> Could you include more info about the compiler versions you tried
> and maybe some objdump? We'll have to take your word for it getting
> optimized out, would be great if we had more proof in the commit msg.
> --
> pw-bot: cr

Thanks for the feedback.
I'll send a v2 with more background soon.

On the other hand this function is only ever
executed once, so even if it is slightly inefficient
it shouldn't matter.

Thomas