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

From: Sabrina Dubroca
Date: Thu Aug 24 2023 - 09:03:29 EST


2023-08-23, 07:53:18 -0700, Jakub Kicinski wrote:
> On Wed, 23 Aug 2023 10:14:48 +0200 (GMT+02:00) linux@xxxxxxxxxxxxxx
> wrote:
> > > 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.
>
> Oh you're right, somehow I thought it was for every alloc.
> You can mention it's only run at init in the commit msg if
> that's easier.

We could also add __init annotations to skb_ext_total_length and
skb_extensions_init to make that clearer.

--
Sabrina