From 67e28ffd864eebbaf48b404d0a8cb4edd2bdc924 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 9 Mar 2011 20:42:07 -0800
Subject: ipv4: Optimize flow initialization in input route lookup.

Like in commit 44713b67db10c774f14280c129b0d5fd13c70cf2
("ipv4: Optimize flow initialization in output route lookup."
we can optimize the on-stack flow setup to only initialize
the members which are actually used.

Otherwise we bzero the entire structure, then initialize
explicitly the first half of it.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/route.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 92a24ea34c1b..ac32d8f3d68f 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2081,12 +2081,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 {
 	struct fib_result res;
 	struct in_device *in_dev = __in_dev_get_rcu(dev);
-	struct flowi fl = { .fl4_dst	= daddr,
-			    .fl4_src	= saddr,
-			    .fl4_tos	= tos,
-			    .fl4_scope	= RT_SCOPE_UNIVERSE,
-			    .mark = skb->mark,
-			    .iif = dev->ifindex };
+	struct flowi fl;
 	unsigned	flags = 0;
 	u32		itag = 0;
 	struct rtable * rth;
@@ -2123,6 +2118,13 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	/*
 	 *	Now we are ready to route packet.
 	 */
+	fl.oif = 0;
+	fl.iif = dev->ifindex;
+	fl.mark = skb->mark;
+	fl.fl4_dst = daddr;
+	fl.fl4_src = saddr;
+	fl.fl4_tos = tos;
+	fl.fl4_scope = RT_SCOPE_UNIVERSE;
 	err = fib_lookup(net, &fl, &res);
 	if (err != 0) {
 		if (!IN_DEV_FORWARD(in_dev))
-- 
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