Hello,
</snip>
> > I'm not sure about your diff see below.
>
> visa@ pointed out that PF_LOCK will introduce a potential sleep inside
> if_vinput(),
> making this unsafe, so here's a less optimistic diff where only the vlan list
> traversal is inside the SMR read section, and vlan_softcs are still
> refcounted.
> I probably need to rework some other unsent SRP->SMR diffs now too.
less optimistic variant looks better. Though I have one
question related to refcnt_finalize().
</snip>
> @@ -257,6 +239,7 @@ vlan_clone_destroy(struct ifnet *ifp)
>
> ether_ifdetach(ifp);
> if_detach(ifp);
> + smr_barrier();
> refcnt_finalize(&sc->sc_refcnt, "vlanrefs");
^^^^
I think a protection should be added so there will be at most 1 thread
calling to refcnt_finalize(). I've noticed vlan_clone_destroy() does
->sc_dead = 1; couple line earlier under protection of NET_LOCK(). Would it
make sense to do if (->sc_dead == 1) first? We would just bail out if
->sc_dead will be set already, because there is vlan_clone_destroy() in
progress already.
Otherwise the change looks good.
thanks and
regards
sashan
