Subject: Re: [PATCH net-2.6] Re: rib_trie / Fix inflate_threshold_root. Now=15 size=11 bits

From: Jarek Poplawski <[email-masked]>
Date: Sun, 5 Jul 2009 18:20:03 +0200

On Sun, Jul 05, 2009 at 02:30:03AM +0200, Paweł Staszewski wrote:
> Oh
>
> I forgot - please Jarek give me patch with sync rcu and i will make test  
> on preempt kernel

Probably non-preempt kernel might need something like this more, but
comparing is always interesting. This patch is based on Paul's
suggestion (I hope).

Thanks,
Jarek P.
---> (synchronize take 7; apply on top of the 2.6.29.x with the last
	all-in-one patch, or net-2.6)

 net/ipv4/fib_trie.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 00a54b2..fce8238 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -164,6 +164,7 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn);
 static struct tnode *halve(struct trie *t, struct tnode *tn);
 /* tnodes to free after resize(); protected by RTNL */
 static struct tnode *tnode_free_head;
+static size_t tnode_free_size;
 
 static struct kmem_cache *fn_alias_kmem __read_mostly;
 static struct kmem_cache *trie_leaf_kmem __read_mostly;
@@ -393,6 +394,8 @@ static void tnode_free_safe(struct tnode *tn)
 	BUG_ON(IS_LEAF(tn));
 	tn->tnode_free = tnode_free_head;
 	tnode_free_head = tn;
+	tnode_free_size += sizeof(struct tnode) +
+			   (sizeof(struct node *) << tn->bits);
 }
 
 static void tnode_free_flush(void)
@@ -404,6 +407,11 @@ static void tnode_free_flush(void)
 		tn->tnode_free = NULL;
 		tnode_free(tn);
 	}
+
+	if (tnode_free_size >= PAGE_SIZE * 128) {
+		tnode_free_size = 0;
+		synchronize_rcu();
+	}
 }
 
 static struct leaf *leaf_new(void)