From: Thomas Graf <tgraf@suug.ch>
Date: Tue, 5 Jul 2005 21:13:41 +0000 (-0700)
Subject: [NET]: Reduce size of sk_buff by 4 bytes
X-Git-Tag: firefly_0821_release~43098^2~36
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1cbb3380ef683f742876f48e3739b3df4ea9e168;p=firefly-linux-kernel-4.4.55.git

[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>
---

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 1e6290f4f81e..14b950413495 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;