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-rw-r--r--target/linux/generic/pending-3.18/080-18-fib_trie-Add-tracking-value-for-suffix-length.patch234
1 files changed, 0 insertions, 234 deletions
diff --git a/target/linux/generic/pending-3.18/080-18-fib_trie-Add-tracking-value-for-suffix-length.patch b/target/linux/generic/pending-3.18/080-18-fib_trie-Add-tracking-value-for-suffix-length.patch
deleted file mode 100644
index 6a4a45e952..0000000000
--- a/target/linux/generic/pending-3.18/080-18-fib_trie-Add-tracking-value-for-suffix-length.patch
+++ /dev/null
@@ -1,234 +0,0 @@
-From: Alexander Duyck <alexander.h.duyck@redhat.com>
-Date: Wed, 31 Dec 2014 10:57:08 -0800
-Subject: [PATCH] fib_trie: Add tracking value for suffix length
-
-This change adds a tracking value for the maximum suffix length of all
-prefixes stored in any given tnode. With this value we can determine if we
-need to backtrace or not based on if the suffix is greater than the pos
-value.
-
-By doing this we can reduce the CPU overhead for lookups in the local table
-as many of the prefixes there are 32b long and have a suffix length of 0
-meaning we can immediately backtrace to the root node without needing to
-test any of the nodes between it and where we ended up.
-
-Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
-Signed-off-by: David S. Miller <davem@davemloft.net>
----
-
---- a/net/ipv4/fib_trie.c
-+++ b/net/ipv4/fib_trie.c
-@@ -96,6 +96,7 @@ struct tnode {
- t_key key;
- unsigned char bits; /* 2log(KEYLENGTH) bits needed */
- unsigned char pos; /* 2log(KEYLENGTH) bits needed */
-+ unsigned char slen;
- struct tnode __rcu *parent;
- struct rcu_head rcu;
- union {
-@@ -311,6 +312,7 @@ static struct tnode *leaf_new(t_key key)
- * as the nodes are searched
- */
- l->key = key;
-+ l->slen = 0;
- l->pos = 0;
- /* set bits to 0 indicating we are not a tnode */
- l->bits = 0;
-@@ -342,6 +344,7 @@ static struct tnode *tnode_new(t_key key
-
- if (tn) {
- tn->parent = NULL;
-+ tn->slen = pos;
- tn->pos = pos;
- tn->bits = bits;
- tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
-@@ -387,6 +390,9 @@ static void put_child(struct tnode *tn,
- else if (!wasfull && isfull)
- tn->full_children++;
-
-+ if (n && (tn->slen < n->slen))
-+ tn->slen = n->slen;
-+
- rcu_assign_pointer(tn->child[i], n);
- }
-
-@@ -635,6 +641,41 @@ static int halve(struct trie *t, struct
- return 0;
- }
-
-+static unsigned char update_suffix(struct tnode *tn)
-+{
-+ unsigned char slen = tn->pos;
-+ unsigned long stride, i;
-+
-+ /* search though the list of children looking for nodes that might
-+ * have a suffix greater than the one we currently have. This is
-+ * why we start with a stride of 2 since a stride of 1 would
-+ * represent the nodes with suffix length equal to tn->pos
-+ */
-+ for (i = 0, stride = 0x2ul ; i < tnode_child_length(tn); i += stride) {
-+ struct tnode *n = tnode_get_child(tn, i);
-+
-+ if (!n || (n->slen <= slen))
-+ continue;
-+
-+ /* update stride and slen based on new value */
-+ stride <<= (n->slen - slen);
-+ slen = n->slen;
-+ i &= ~(stride - 1);
-+
-+ /* if slen covers all but the last bit we can stop here
-+ * there will be nothing longer than that since only node
-+ * 0 and 1 << (bits - 1) could have that as their suffix
-+ * length.
-+ */
-+ if ((slen + 1) >= (tn->pos + tn->bits))
-+ break;
-+ }
-+
-+ tn->slen = slen;
-+
-+ return slen;
-+}
-+
- /* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
- * the Helsinki University of Technology and Matti Tikkanen of Nokia
- * Telecommunications, page 6:
-@@ -790,6 +831,19 @@ no_children:
- /* drop dead node */
- tnode_free_init(tn);
- tnode_free(tn);
-+ return;
-+ }
-+
-+ /* Return if at least one deflate was run */
-+ if (max_work != MAX_WORK)
-+ return;
-+
-+ /* push the suffix length to the parent node */
-+ if (tn->slen > tn->pos) {
-+ unsigned char slen = update_suffix(tn);
-+
-+ if (tp && (slen > tp->slen))
-+ tp->slen = slen;
- }
- }
-
-@@ -818,8 +872,58 @@ static inline struct list_head *get_fa_h
- return &li->falh;
- }
-
--static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
-+static void leaf_pull_suffix(struct tnode *l)
-+{
-+ struct tnode *tp = node_parent(l);
-+
-+ while (tp && (tp->slen > tp->pos) && (tp->slen > l->slen)) {
-+ if (update_suffix(tp) > l->slen)
-+ break;
-+ tp = node_parent(tp);
-+ }
-+}
-+
-+static void leaf_push_suffix(struct tnode *l)
-+{
-+ struct tnode *tn = node_parent(l);
-+
-+ /* if this is a new leaf then tn will be NULL and we can sort
-+ * out parent suffix lengths as a part of trie_rebalance
-+ */
-+ while (tn && (tn->slen < l->slen)) {
-+ tn->slen = l->slen;
-+ tn = node_parent(tn);
-+ }
-+}
-+
-+static void remove_leaf_info(struct tnode *l, struct leaf_info *old)
-+{
-+ struct hlist_node *prev;
-+
-+ /* record the location of the pointer to this object */
-+ prev = rtnl_dereference(hlist_pprev_rcu(&old->hlist));
-+
-+ /* remove the leaf info from the list */
-+ hlist_del_rcu(&old->hlist);
-+
-+ /* if we emptied the list this leaf will be freed and we can sort
-+ * out parent suffix lengths as a part of trie_rebalance
-+ */
-+ if (hlist_empty(&l->list))
-+ return;
-+
-+ /* if we removed the tail then we need to update slen */
-+ if (!rcu_access_pointer(hlist_next_rcu(prev))) {
-+ struct leaf_info *li = hlist_entry(prev, typeof(*li), hlist);
-+
-+ l->slen = KEYLENGTH - li->plen;
-+ leaf_pull_suffix(l);
-+ }
-+}
-+
-+static void insert_leaf_info(struct tnode *l, struct leaf_info *new)
- {
-+ struct hlist_head *head = &l->list;
- struct leaf_info *li = NULL, *last = NULL;
-
- if (hlist_empty(head)) {
-@@ -836,6 +940,12 @@ static void insert_leaf_info(struct hlis
- else
- hlist_add_before_rcu(&new->hlist, &li->hlist);
- }
-+
-+ /* if we added to the tail node then we need to update slen */
-+ if (!rcu_access_pointer(hlist_next_rcu(&new->hlist))) {
-+ l->slen = KEYLENGTH - new->plen;
-+ leaf_push_suffix(l);
-+ }
- }
-
- /* rcu_read_lock needs to be hold by caller from readside */
-@@ -925,7 +1035,7 @@ static struct list_head *fib_insert_node
- /* we have found a leaf. Prefixes have already been compared */
- if (IS_LEAF(n)) {
- /* Case 1: n is a leaf, and prefixes match*/
-- insert_leaf_info(&n->list, li);
-+ insert_leaf_info(n, li);
- return fa_head;
- }
-
-@@ -939,7 +1049,7 @@ static struct list_head *fib_insert_node
- return NULL;
- }
-
-- insert_leaf_info(&l->list, li);
-+ insert_leaf_info(l, li);
-
- /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
- *
-@@ -1206,7 +1316,7 @@ int fib_table_lookup(struct fib_table *t
- /* only record pn and cindex if we are going to be chopping
- * bits later. Otherwise we are just wasting cycles.
- */
-- if (index) {
-+ if (n->slen > n->pos) {
- pn = n;
- cindex = index;
- }
-@@ -1225,7 +1335,7 @@ int fib_table_lookup(struct fib_table *t
- * between the key and the prefix exist in the region of
- * the lsb and higher in the prefix.
- */
-- if (unlikely(prefix_mismatch(key, n)))
-+ if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
- goto backtrace;
-
- /* exit out and process leaf */
-@@ -1425,7 +1535,7 @@ int fib_table_delete(struct fib_table *t
- tb->tb_num_default--;
-
- if (list_empty(fa_head)) {
-- hlist_del_rcu(&li->hlist);
-+ remove_leaf_info(l, li);
- free_leaf_info(li);
- }
-
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-25 11:51:55 +0000