[NET]: Decrease skb->cb[] to 40 bytes.

No control block usage, even on 64-bit, needs
the full current 48 bytes.  This brings sk_buff
size down to 256 bytes on 64-bit platforms and
fixes some performance regressions due to the
addition of the input_dev member.

Signed-off-by: David S. Miller <davem@redhat.com>

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 3d0ba45fa88d25661ef13de203193de563e6c34f..11f514844817d0c9297b86e3fcc802668b9de936 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -233,7 +233,7 @@ struct sk_buff {
         * want to keep them across layers you have to do a skb_clone()
         * first. This is owned by whoever has the skb queued ATM.
         */
-       char                    cb[48];
+       char                    cb[40];
 
        unsigned int            len,
                                data_len,