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authorAlexander Duyck <alexander.h.duyck@redhat.com>2014-12-31 10:57:02 -0800
committerDavid S. Miller <davem@davemloft.net>2014-12-31 18:25:55 -0500
commit21d1f11db0e2f20a549ad8322879507850544670 (patch)
treeb8e624c9b2d1426f74d39090e982037daabb2d2f /net/ipv4/fib_trie.c
parent12c081a5c82ef64a90906247cecfa5422962e387 (diff)
downloadop-kernel-dev-21d1f11db0e2f20a549ad8322879507850544670.zip
op-kernel-dev-21d1f11db0e2f20a549ad8322879507850544670.tar.gz
fib_trie: Remove checks for index >= tnode_child_length from tnode_get_child
For some reason the compiler doesn't seem to understand that when we are in a loop that runs from tnode_child_length - 1 to 0 we don't expect the value of tn->bits to change. As such every call to tnode_get_child was rerunning tnode_chile_length which ended up consuming quite a bit of space in the resultant assembly code. I have gone though and verified that in all cases where tnode_get_child is used we are either winding though a fixed loop from tnode_child_length - 1 to 0, or are in a fastpath case where we are verifying the value by either checking for any remaining bits after shifting index by bits and testing for leaf, or by using tnode_child_length. size net/ipv4/fib_trie.o Before: text data bss dec hex filename 15506 376 8 15890 3e12 net/ipv4/fib_trie.o After: text data bss dec hex filename 14827 376 8 15211 3b6b net/ipv4/fib_trie.o Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/fib_trie.c')
-rw-r--r--net/ipv4/fib_trie.c14
1 files changed, 5 insertions, 9 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 0c88df0..87fc9a4 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -186,8 +186,6 @@ static inline unsigned long tnode_child_length(const struct tnode *tn)
static inline struct tnode *tnode_get_child(const struct tnode *tn,
unsigned long i)
{
- BUG_ON(i >= tnode_child_length(tn));
-
return rtnl_dereference(tn->child[i]);
}
@@ -195,8 +193,6 @@ static inline struct tnode *tnode_get_child(const struct tnode *tn,
static inline struct tnode *tnode_get_child_rcu(const struct tnode *tn,
unsigned long i)
{
- BUG_ON(i >= tnode_child_length(tn));
-
return rcu_dereference_rtnl(tn->child[i]);
}
@@ -371,7 +367,7 @@ static inline int tnode_full(const struct tnode *tn, const struct tnode *n)
*/
static void put_child(struct tnode *tn, unsigned long i, struct tnode *n)
{
- struct tnode *chi = rtnl_dereference(tn->child[i]);
+ struct tnode *chi = tnode_get_child(tn, i);
int isfull, wasfull;
BUG_ON(i >= tnode_child_length(tn));
@@ -867,7 +863,7 @@ static struct tnode *fib_find_node(struct trie *t, u32 key)
if (IS_LEAF(n))
break;
- n = rcu_dereference_rtnl(n->child[index]);
+ n = tnode_get_child_rcu(n, index);
}
return n;
@@ -934,7 +930,7 @@ static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
}
tp = n;
- n = rcu_dereference_rtnl(n->child[index]);
+ n = tnode_get_child_rcu(n, index);
}
l = leaf_new(key);
@@ -1215,7 +1211,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
cindex = index;
}
- n = rcu_dereference(n->child[index]);
+ n = tnode_get_child_rcu(n, index);
if (unlikely(!n))
goto backtrace;
}
@@ -1835,7 +1831,7 @@ static void trie_collect_stats(struct trie *t, struct trie_stat *s)
if (n->bits < MAX_STAT_DEPTH)
s->nodesizes[n->bits]++;
- for (i = 0; i < tnode_child_length(n); i++) {
+ for (i = tnode_child_length(n); i--;) {
if (!rcu_access_pointer(n->child[i]))
s->nullpointers++;
}
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