gro: Avoid unnecessary comparison after skb_gro_header
For the overwhelming majority of cases, skb_gro_header's return
value cannot be NULL. Yet we must check it because of its current
form. This patch splits it up into multiple functions in order
to avoid this.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 2e44a04..371ece5 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1132,20 +1132,25 @@
NAPI_GRO_CB(skb)->data_offset += len;
}
-static inline void *skb_gro_header(struct sk_buff *skb, unsigned int hlen)
+static inline void *skb_gro_header_fast(struct sk_buff *skb,
+ unsigned int offset)
{
- unsigned int offset = skb_gro_offset(skb);
-
- hlen += offset;
- if (NAPI_GRO_CB(skb)->frag0_len < hlen) {
- NAPI_GRO_CB(skb)->frag0 = NULL;
- NAPI_GRO_CB(skb)->frag0_len = 0;
- return pskb_may_pull(skb, hlen) ? skb->data + offset : NULL;
- }
-
return NAPI_GRO_CB(skb)->frag0 + offset;
}
+static inline int skb_gro_header_hard(struct sk_buff *skb, unsigned int hlen)
+{
+ return NAPI_GRO_CB(skb)->frag0_len < hlen;
+}
+
+static inline void *skb_gro_header_slow(struct sk_buff *skb, unsigned int hlen,
+ unsigned int offset)
+{
+ NAPI_GRO_CB(skb)->frag0 = NULL;
+ NAPI_GRO_CB(skb)->frag0_len = 0;
+ return pskb_may_pull(skb, hlen) ? skb->data + offset : NULL;
+}
+
static inline void *skb_gro_mac_header(struct sk_buff *skb)
{
return NAPI_GRO_CB(skb)->frag0 ?: skb_mac_header(skb);
