[NET]: Reduce size of sk_buff by 4 bytes

Reduce local_df to a bit field and ip_summed to a 2 bits
field thus saving 13 bits. Move bit fields, packet type,
and protocol into the spare area between the priority
and the destructor. Saves 4 bytes on both, 32bit and
64bit architectures.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 7 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 1e6290f4f8..14b9504134 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -248,17 +248,18 @@ struct sk_buff {
                                 data_len,
                                 mac_len,
                                 csum;
-        unsigned char           local_df,
-                                cloned:1,
-                                nohdr:1,
-                                pkt_type,
-                                ip_summed;
         __u32                   priority;
-        unsigned short          protocol;
+        __u8                    local_df:1,
+                                cloned:1,
+                                ip_summed:2,
+                                nohdr:1;
+                                /* 3 bits spare */
+        __u8                    pkt_type;
+        __u16                   protocol;
 
         void                    (*destructor)(struct sk_buff *skb);
 #ifdef CONFIG_NETFILTER
-        unsigned long           nfmark;
+        unsigned long           nfmark;
         __u32                   nfcache;
         __u32                   nfctinfo;
         struct nf_conntrack     *nfct;