quoted

-             page = alloc_page(gfp_mask);
+             page = skb_frag_page(f);
+             if (page_count(page) == 1) {
+                     skb_frag_ref(skb, i);

This could be : get_page(page);

Ah, indeed. Thanks.

quoted

+                     goto copy_done;
+             }
+
+             if (f->size > PAGE_SIZE) {
+                     order = get_order(f->size);
+                     mask |= __GFP_COMP;

Note that this would probably fail under memory pressure.

We could instead try to explode the few segments into order-0 only
pages.

Good point. I'll revise to use only order-0 here.