On Fri, Sep 07, 2018 at 11:22:00AM +0800, Jason Wang wrote: > > > @@ -1668,6 +1668,9 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, > > > if (copied != len) > > > return ERR_PTR(-EFAULT); > > > + get_page(alloc_frag->page); > > > + alloc_frag->offset += buflen; > > > + > > This adds an atomic op on XDP_DROP which is a data path > > operation for some workloads. > > Yes, I have patch on top to amortize this, the idea is to have a very big > refcount once after the frag was allocated and maintain a bias and decrease > them all when allocating new frags.' Why bother with refcounting for a drop though? It should be simple. -- MST
