net: NET_SKB_PAD should depend on L1_CACHE_BYTES

[linux-2.6.git] / include / linux / skbuff.h

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 7cdfb4d52847e6f733df1538f48fc73508e3d13e..ac74ee085d743139faddc1f36958a99c0f7f6a05 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -380,7 +380,10 @@ struct sk_buff {
        kmemcheck_bitfield_begin(flags2);
        __u16                   queue_mapping:16;
 #ifdef CONFIG_IPV6_NDISC_NODETYPE
-       __u8                    ndisc_nodetype:2;
+       __u8                    ndisc_nodetype:2,
+                               deliver_no_wcard:1;
+#else
+       __u8                    deliver_no_wcard:1;
 #endif
        kmemcheck_bitfield_end(flags2);
 
@@ -501,7 +504,7 @@ static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
        return __alloc_skb(size, priority, 1, -1);
 }
 
-extern int skb_recycle_check(struct sk_buff *skb, int skb_size);
+extern bool skb_recycle_check(struct sk_buff *skb, int skb_size);
 
 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
 extern struct sk_buff *skb_clone(struct sk_buff *skb,
@@ -1411,12 +1414,14 @@ static inline int skb_network_offset(const struct sk_buff *skb)
  *
  * Various parts of the networking layer expect at least 32 bytes of
  * headroom, you should not reduce this.
- * With RPS, we raised NET_SKB_PAD to 64 so that get_rps_cpus() fetches span
- * a 64 bytes aligned block to fit modern (>= 64 bytes) cache line sizes
+ *
+ * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
+ * to reduce average number of cache lines per packet.
+ * get_rps_cpus() for example only access one 64 bytes aligned block :
  * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
  */
 #ifndef NET_SKB_PAD
-#define NET_SKB_PAD    64
+#define NET_SKB_PAD    max(32, L1_CACHE_BYTES)
 #endif
 
 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
@@ -2129,7 +2134,8 @@ 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;
        }