[RFC PATCH net-next 08/12] tuntap: tweak on the path of non-xdp case in tun_build_skb()
From: Jason Wang <jasowang@redhat.com>
Date: 2018-05-21 09:05:23
Also in:
kvm, lkml
Subsystem:
networking drivers, the rest, tun/tap driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Willem de Bruijn, Jason Wang
If we're sure not to go native XDP, there's no need for several things like touching preemption counter and rcu stuffs. Signed-off-by: Jason Wang <jasowang@redhat.com> --- drivers/net/tun.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index f6e0f96..ed04291 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c@@ -1645,10 +1645,12 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, * of xdp_prog above, this should be rare and for simplicity * we do XDP on skb in case the headroom is not enough. */ - if (hdr->gso_type || !xdp_prog) + if (hdr->gso_type || !xdp_prog) { *skb_xdp = 1; - else - *skb_xdp = 0; + goto build; + } + + *skb_xdp = 0; preempt_disable(); rcu_read_lock();
@@ -1695,6 +1697,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, rcu_read_unlock(); preempt_enable(); +build: skb = build_skb(buf, buflen); if (!skb) { skb = ERR_PTR(-ENOMEM);
--
2.7.4