Re: rib_trie / Fix inflate_threshold_root. Now=15 size=11 bits

[Jarek Poplawski <jarkao2@gmail.com>]

On Fri, Jun 26, 2009 at 03:52:55PM +0200, Robert Olsson wrote:
> 
> Jarek Poplawski writes:
> 
>  Thanks, 
> 
>  Should be worth testing so we synchronize_rcu instead of doing call_rcu's
>  

Alas take 2 (nor 1) doesn't compile, so here it is again.

Thanks,
Jarek P.
--- (take 3 - for testing)

 net/ipv4/fib_trie.c |   30 ++++++++++++++++++++++++------
 1 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 012cf5a..1a4c4b7 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -366,6 +366,17 @@ static void __tnode_vfree(struct work_struct *arg)
 	vfree(tn);
 }
 
+static void __tnode_free(struct tnode *tn)
+{
+	size_t size = sizeof(struct tnode) +
+		      (sizeof(struct node *) << tn->bits);
+
+	if (size <= PAGE_SIZE)
+		kfree(tn);
+	else
+		vfree(tn);
+}
+
 static void __tnode_free_rcu(struct rcu_head *head)
 {
 	struct tnode *tn = container_of(head, struct tnode, rcu);
@@ -402,7 +413,7 @@ static void tnode_free_flush(void)
 	while ((tn = tnode_free_head)) {
 		tnode_free_head = tn->tnode_free;
 		tn->tnode_free = NULL;
-		tnode_free(tn);
+		__tnode_free(tn);
 	}
 }
 
@@ -1021,18 +1032,25 @@ static void trie_rebalance(struct trie *t, struct tnode *tn)
 				      (struct node *)tn, wasfull);
 
 		tp = node_parent((struct node *) tn);
-		tnode_free_flush();
 		if (!tp)
 			break;
 		tn = tp;
 	}
 
+	if (tnode_free_head) {
+		synchronize_rcu();
+		tnode_free_flush();
+	}
+
 	/* Handle last (top) tnode */
-	if (IS_TNODE(tn))
+	if (IS_TNODE(tn)) {
 		tn = (struct tnode *)resize(t, (struct tnode *)tn);
-
-	rcu_assign_pointer(t->trie, (struct node *)tn);
-	tnode_free_flush();
+		rcu_assign_pointer(t->trie, (struct node *)tn);
+		synchronize_rcu();
+		tnode_free_flush();
+	} else {
+		rcu_assign_pointer(t->trie, (struct node *)tn);
+	}
 
 	return;
 }