From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [RFC PATCH net-next 08/12] tuntap: tweak on the path of non-xdp case in tun_build_skb() Date: Mon, 21 May 2018 17:04:29 +0800 Message-ID: <1526893473-20128-9-git-send-email-jasowang@redhat.com> References: <1526893473-20128-1-git-send-email-jasowang@redhat.com> Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: mst@redhat.com, jasowang@redhat.com Return-path: In-Reply-To: <1526893473-20128-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 --- 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