Re: [PATCH net-next v4] net: linux/skbuff.h: combine SKB_EXTENSIONS + KCOV handling

Jakub Kicinski
2020-11-16T15:30:36Z

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!