Merge branch 'fib_trie_remove_leaf_info'

Alexander Duyck says:

====================
fib_trie: Remove leaf_info structure

This patch set removes the leaf_info structure from the IPv4 fib_trie.  The
general idea is that the leaf_info structure itself only held about 6
actual bits of data, beyond that it was mostly just waste.  As such we can
drop the structure, move the 1 byte representing the prefix/suffix length
into the fib_alias and just link it all into one list.

My testing shows that this saves somewhere between 4 to 10ns depending on
the type of test performed.  I'm suspecting that this represents 1 to 2 L1
cache misses saved per look-up.

One side effect of this change is that semantic_match_miss will now only
increment once per leaf instead of once per leaf_info miss.  However the
stat is already skewed now that we perform a preliminary check on the leaf
as a part of the look-up.

I also have gone through and addressed a number of ordering issues in the
first patch since I had misread the behavior of list_add_tail.

I have since run some additional testing and verified the resulting lists
are in the same order when combining multiple prefix length and tos values
in a single leaf.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip_fib.h

@@ -136,7 +136,7 @@ struct fib_result {
 	u32		tclassid;
 	struct fib_info *fi;
 	struct fib_table *table;
-	struct list_head *fa_head;
+	struct hlist_head *fa_head;
 };
 
 struct fib_result_nl {

net/ipv4/fib_lookup.h

@@ -6,11 +6,12 @@
 #include <net/ip_fib.h>
 
 struct fib_alias {
-	struct list_head	fa_list;
+	struct hlist_node	fa_list;
 	struct fib_info		*fa_info;
 	u8			fa_tos;
 	u8			fa_type;
 	u8			fa_state;
+	u8			fa_slen;
 	struct rcu_head		rcu;
 };
 

net/ipv4/fib_semantics.c

@@ -1163,12 +1163,12 @@ int fib_sync_down_dev(struct net_device *dev, int force)
 void fib_select_default(struct fib_result *res)
 {
 	struct fib_info *fi = NULL, *last_resort = NULL;
-	struct list_head *fa_head = res->fa_head;
+	struct hlist_head *fa_head = res->fa_head;
 	struct fib_table *tb = res->table;
 	int order = -1, last_idx = -1;
 	struct fib_alias *fa;
 
-	list_for_each_entry_rcu(fa, fa_head, fa_list) {
+	hlist_for_each_entry_rcu(fa, fa_head, fa_list) {
 		struct fib_info *next_fi = fa->fa_info;
 
 		if (next_fi->fib_scope != res->scope ||