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| author |   Jarek Poplawski <jarkao2@gmail.com> | 2009-07-14 09:41:00 +0000 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2009-07-20 07:39:29 -0700 |
| commit | be916cdebe4dc720a23b1a9bb589f2c22afd6589 (patch) | |
| tree | 310a6de2576aaf6e5a87463ee89bf7bea745badd | |
| parent | ipv4: Use synchronize_rcu() during trie_rebalance() (diff) | |
| download | linux-dev-be916cdebe4dc720a23b1a9bb589f2c22afd6589.tar.xz linux-dev-be916cdebe4dc720a23b1a9bb589f2c22afd6589.zip | |
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 <pstaszewski@itcare.pl>
Reported-by: Jorge Boncompte [DTI2] <jorge@dti2.net>
Tested-by: Pawel Staszewski <pstaszewski@itcare.pl>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/fib_trie.c | 29 |
1 files 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); |