skbuff: add check for non-linear to warn_if_lro and needs_linearize

We can avoid an unecessary cache miss by checking if the skb is non-linear
before accessing gso_size/gso_type in skb_warn_if_lro, the same can also be
done to avoid a cache miss on nr_frags if data_len is 0.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 4 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index bf243fc54959..645e78d395fd 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2129,7 +2129,8 @@ static inline bool skb_warn_if_lro(const struct sk_buff *skb)
         /* LRO sets gso_size but not gso_type, whereas if GSO is really
          * wanted then gso_type will be set. */
         struct skb_shared_info *shinfo = skb_shinfo(skb);
-        if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
+        if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
+            unlikely(shinfo->gso_type == 0)) {
                 __skb_warn_lro_forwarding(skb);
                 return true;
         }
diff --git a/net/core/dev.c b/net/core/dev.c
index ec01a5998d70..3abb3a6058be 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2103,9 +2103,10 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 static inline int skb_needs_linearize(struct sk_buff *skb,
                                       struct net_device *dev)
 {
-        return (skb_has_frags(skb) && !(dev->features & NETIF_F_FRAGLIST)) ||
-               (skb_shinfo(skb)->nr_frags && (!(dev->features & NETIF_F_SG) ||
-                                              illegal_highdma(dev, skb)));
+        return skb_is_nonlinear(skb) &&
+               ((skb_has_frags(skb) && !(dev->features & NETIF_F_FRAGLIST)) ||
+                (skb_shinfo(skb)->nr_frags && (!(dev->features & NETIF_F_SG) ||
+                                              illegal_highdma(dev, skb))));
 }
 
 /**