From be916cdebe4dc720a23b1a9bb589f2c22afd6589 Mon Sep 17 00:00:00 2001 From: Jarek Poplawski Date: Tue, 14 Jul 2009 09:41:00 +0000 Subject: ipv4: Fix inflate_threshold_root automatically During large updates there could be triggered warnings like: "Fix inflate_threshold_root. Now=25 size=11 bits" if inflate() of the root node isn't finished in 10 loops. It should be much rarer now, after changing the threshold from 15 to 25, and a temporary problem, so this patch tries to handle it automatically using a fix variable to increase by one inflate threshold for next root resizes (up to the 35 limit, max fix = 10). The fix variable is decreased when root's inflate() finishes below 7 loops (even if some other, smaller table/ trie is updated -- for simplicity the fix variable is global for now). Reported-by: Pawel Staszewski Reported-by: Jorge Boncompte [DTI2] Tested-by: Pawel Staszewski Signed-off-by: Jarek Poplawski Signed-off-by: Robert Olsson Signed-off-by: David S. Miller --- net/ipv4/fib_trie.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 58ba9f4f2c92..5741d1306cc5 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -327,6 +327,8 @@ static const int inflate_threshold = 50; static const int halve_threshold_root = 15; static const int inflate_threshold_root = 25; +static int inflate_threshold_root_fix; +#define INFLATE_FIX_MAX 10 /* a comment in resize() */ static void __alias_free_mem(struct rcu_head *head) { @@ -617,7 +619,8 @@ static struct node *resize(struct trie *t, struct tnode *tn) /* Keep root node larger */ if (!tn->parent) - inflate_threshold_use = inflate_threshold_root; + inflate_threshold_use = inflate_threshold_root + + inflate_threshold_root_fix; else inflate_threshold_use = inflate_threshold; @@ -641,15 +644,27 @@ static struct node *resize(struct trie *t, struct tnode *tn) } if (max_resize < 0) { - if (!tn->parent) - pr_warning("Fix inflate_threshold_root." - " Now=%d size=%d bits\n", - inflate_threshold_root, tn->bits); - else + if (!tn->parent) { + /* + * It was observed that during large updates even + * inflate_threshold_root = 35 might be needed to avoid + * this warning; but it should be temporary, so let's + * try to handle this automatically. + */ + if (inflate_threshold_root_fix < INFLATE_FIX_MAX) + inflate_threshold_root_fix++; + else + pr_warning("Fix inflate_threshold_root." + " Now=%d size=%d bits fix=%d\n", + inflate_threshold_root, tn->bits, + inflate_threshold_root_fix); + } else { pr_warning("Fix inflate_threshold." " Now=%d size=%d bits\n", inflate_threshold, tn->bits); - } + } + } else if (max_resize > 3 && !tn->parent && inflate_threshold_root_fix) + inflate_threshold_root_fix--; check_tnode(tn); -- cgit v1.2.3