On Mon, 12 Oct 2020 at 09:04, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: > > On Sat, Oct 10, 2020 at 5:14 PM Jakub Kicinski <kuba@xxxxxxxxxx> wrote: > > > > On Sat, 10 Oct 2020 09:54:57 +0200 Dmitry Vyukov wrote: > > > On Sat, Oct 10, 2020 at 1:16 AM Jakub Kicinski <kuba@xxxxxxxxxx> wrote: [...] > > > > Could you use skb_extensions for this? > > > > > > Why? If for space, this is already under a non-production ifdef. > > > > I understand, but the skb_ext infra is there for uncommon use cases > > like this one. Any particular reason you don't want to use it? > > The slight LoC increase? > > > > Is there any precedent for adding the kcov field to other performance > > critical structures? It would be great to come to some conclusion on where exactly to store kcov_handle. Technically, it is possible to use skb extensions for the purpose, though it will indeed slightly increase the complexity. Jakub, you think that kcov_handle should be added as an skb extension, right? Though I do not really object to moving the field, it still seems to me that sk_buff itself is a better place. Right now skb extensions store values that are local to specific protocols and that are only meaningful in the context of these protocols (correct me if I'm wrong). Although this patch only adds remote kcov coverage to the wifi code, kcov_handle can be meaningful for other protocols as well - just like the already existing sk_buff fields. So adding kcov_handle to skb extensions will break this logical separation. -- Best regards, Aleksandr
