Nishit Shah <nsshah.82@xxxxxxxxx> wrote: > On Wed, Apr 17, 2013 at 10:17 PM, Patrick McHardy <kaber@xxxxxxxxx> wrote: > > > > Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx> [..] > > diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c > > index 5e280b3..ef3cdb4 100644 > > --- a/net/netfilter/nfnetlink_queue_core.c > > +++ b/net/netfilter/nfnetlink_queue_core.c > > @@ -339,7 +339,8 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue, > > if (queue->flags & NFQA_CFG_F_CONNTRACK) > > ct = nfqnl_ct_get(entskb, &size, &ctinfo); > > > > - skb = alloc_skb(size, GFP_ATOMIC); > > + skb = nfnetlink_alloc_skb(&init_net, size, queue->peer_portid, > > + GFP_ATOMIC); > > if (!skb) > > return NULL; > > > > does this mean that we have a true zero copy support with Eric D's > patch (nfnetlink_queue: zero-copy support) and this patch ? No. In both socket and mmap case there is one copy involved. Before Erics patch, there were two: first copy: skb_copy_bits() that copies to packet payload into the netlink message second copy: copy to userspace when recv() is called Patricks mmap patch removes the second copy; as the netlink message is already allocated in userspace memory (the mmap ring). Erics patch avoids the first copy by only copying fragments' addresses instead of the payload. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
