| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Mon, 02 Mar 2015 13:32:22 -0800
From: Alexander Duyck <alexander.h.duyck@...hat.com>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net
Subject: [net-next PATCH 1/6] fib_trie: Only resize tnodes once instead of
on each leaf removal in fib_table_flush
This change makes it so that we only call resize on the tnodes, instead of
from each of the leaves. By doing this we can significantly reduce the
amount of time spent resizing as we can update all of the leaves in the
tnode first before we make any determinations about resizing. As a result
we can simply free the tnode in the case that all of the leaves from a
given tnode are flushed instead of resizing with each leaf removed.
Signed-off-by: Alexander Duyck <alexander.h.duyck@...hat.com>
---
net/ipv4/fib_trie.c | 141 ++++++++++++++++++++++++++++-----------------------
1 file changed, 78 insertions(+), 63 deletions(-)
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index f485345..d8b68b4 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1400,25 +1400,6 @@ found:
EXPORT_SYMBOL_GPL(fib_table_lookup);
/*
- * Remove the leaf and return parent.
- */
-static void trie_leaf_remove(struct trie *t, struct tnode *l)
-{
- struct tnode *tp = node_parent(l);
-
- pr_debug("entering trie_leaf_remove(%p)\n", l);
-
- if (tp) {
- put_child(tp, get_index(l->key, tp), NULL);
- trie_rebalance(t, tp);
- } else {
- RCU_INIT_POINTER(t->trie, NULL);
- }
-
- node_free(l);
-}
-
-/*
* Caller must hold RTNL.
*/
int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
@@ -1483,8 +1464,18 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
if (!plen)
tb->tb_num_default--;
- if (hlist_empty(&l->leaf))
- trie_leaf_remove(t, l);
+ if (hlist_empty(&l->leaf)) {
+ struct tnode *tp = node_parent(l);
+
+ if (tp) {
+ put_child(tp, get_index(l->key, tp), NULL);
+ trie_rebalance(t, tp);
+ } else {
+ RCU_INIT_POINTER(t->trie, NULL);
+ }
+
+ node_free(l);
+ }
if (fa->fa_state & FA_S_ACCESSED)
rt_cache_flush(cfg->fc_nlinfo.nl_net);
@@ -1494,33 +1485,6 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
return 0;
}
-static int trie_flush_leaf(struct tnode *l)
-{
- struct hlist_node *tmp;
- unsigned char slen = 0;
- struct fib_alias *fa;
- int found = 0;
-
- hlist_for_each_entry_safe(fa, tmp, &l->leaf, fa_list) {
- struct fib_info *fi = fa->fa_info;
-
- if (fi && (fi->fib_flags & RTNH_F_DEAD)) {
- hlist_del_rcu(&fa->fa_list);
- fib_release_info(fa->fa_info);
- alias_free_mem_rcu(fa);
- found++;
-
- continue;
- }
-
- slen = fa->fa_slen;
- }
-
- l->slen = slen;
-
- return found;
-}
-
/* Scan for the next right leaf starting at node p->child[idx]
* Since we have back pointer, no recursion necessary.
*/
@@ -1588,30 +1552,81 @@ static struct tnode *trie_leafindex(struct trie *t, int index)
*/
int fib_table_flush(struct fib_table *tb)
{
- struct trie *t = (struct trie *) tb->tb_data;
- struct tnode *l, *ll = NULL;
+ struct trie *t = (struct trie *)tb->tb_data;
+ struct hlist_node *tmp;
+ struct fib_alias *fa;
+ struct tnode *n, *pn;
+ unsigned long cindex;
+ unsigned char slen;
int found = 0;
- for (l = trie_firstleaf(t); l; l = trie_nextleaf(l)) {
- found += trie_flush_leaf(l);
+ n = rcu_dereference(t->trie);
+ if (!n)
+ goto flush_complete;
+
+ pn = NULL;
+ cindex = 0;
+
+ while (IS_TNODE(n)) {
+ /* record pn and cindex for leaf walking */
+ pn = n;
+ cindex = 1ul << n->bits;
+backtrace:
+ /* walk trie in reverse order */
+ do {
+ while (!(cindex--)) {
+ t_key pkey = pn->key;
+
+ n = pn;
+ pn = node_parent(n);
+
+ /* resize completed node */
+ resize(t, n);
+
+ /* if we got the root we are done */
+ if (!pn)
+ goto flush_complete;
- if (ll) {
- if (hlist_empty(&ll->leaf))
- trie_leaf_remove(t, ll);
- else
- leaf_pull_suffix(ll);
+ cindex = get_index(pkey, pn);
+ }
+
+ /* grab the next available node */
+ n = tnode_get_child(pn, cindex);
+ } while (!n);
+ }
+
+ /* track slen in case any prefixes survive */
+ slen = 0;
+
+ hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
+ struct fib_info *fi = fa->fa_info;
+
+ if (fi && (fi->fib_flags & RTNH_F_DEAD)) {
+ hlist_del_rcu(&fa->fa_list);
+ fib_release_info(fa->fa_info);
+ alias_free_mem_rcu(fa);
+ found++;
+
+ continue;
}
- ll = l;
+ slen = fa->fa_slen;
}
- if (ll) {
- if (hlist_empty(&ll->leaf))
- trie_leaf_remove(t, ll);
- else
- leaf_pull_suffix(ll);
+ /* update leaf slen */
+ n->slen = slen;
+
+ if (hlist_empty(&n->leaf)) {
+ put_child_root(pn, t, n->key, NULL);
+ node_free(n);
+ } else {
+ leaf_pull_suffix(n);
}
+ /* if trie is leaf only loop is completed */
+ if (pn)
+ goto backtrace;
+flush_complete:
pr_debug("trie_flush found=%d\n", found);
return found;
}
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists